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Thread: How to accurize an AR15

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    How to accurize an AR15

    I am looking at processes to accurize the AR15 platform in the same manner gunsmiths accurize bolt actions. I am looking for insight into machining and truing the actions rather than the usual "buy a quality barrel and trigger" statements.
    Any input will help!

    Thanks,
    LongArm
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    Re: How to accurize an AR15

    much like a Savage bolt action, the AR platforn is modular... so it doesn't require quite as much "truing", but you can square up the front of the receiver with the threads, square the bolt face with the threads, etc... just like you would any other rifle... you can also bed the upper and lower receivers to each other

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    Re: How to accurize an AR15

    Quality upper's and lower's are true,not mutch left to do exept add what you already said..
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    Re: How to accurize an AR15

    From what I have been told by a reputable AR smith when I asked a similar question...the barrel extension to bolt fit is critical. .015" tolerance. As well as a clamp on gas block and best barrel you can afford.
    Jesse

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    Re: How to accurize an AR15

    Originally Posted By: MuleHunter
    From what I have been told by a reputable AR smith when I asked a similar question...the barrel extension to bolt fit is critical. .015" tolerance. As well as a clamp on gas block and best barrel you can afford.

    I have spoken with q bunch of people who always fridge at the thought of clamp on gas blocks.
    I run the JP on mine without a single issue but I have checked to make sure it stays tight also.
    Never has needed more torqe on the bolt even after thousands of rounds.
    My WOA with matching bolt shoots 1/2 MOA and was priced much lower than most barrels I looked at.
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    Re: How to accurize an AR15

    I as well use WOA and have 9000 rounds on my current barrel with clamp on PRI and its .5 MOA capable,matter fact I shot it with some hi end built ar15 WEAPONS with no less results..
    This is my 6th WOA barrel and all ran the same load and dope.
    NO VOODOO just bolt it up and roll..


    Originally Posted By: strangedays
    Originally Posted By: MuleHunter
    From what I have been told by a reputable AR smith when I asked a similar question...the barrel extension to bolt fit is critical. .015" tolerance. As well as a clamp on gas block and best barrel you can afford.

    I have spoken with q bunch of people who always fridge at the thought of clamp on gas blocks.
    I run the JP on mine without a single issue but I have checked to make sure it stays tight also.
    Never has needed more torqe on the bolt even after thousands of rounds.
    My WOA with matching bolt shoots 1/2 MOA and was priced much lower than most barrels I looked at.
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    Re: How to accurize an AR15

    True receiver, use a good barrel 1/8 or 1/7,freefloat barrel,and use a heavier buffer ie T2 or T3.Dont forget a good trigger for what ever you are doing.Two stage for target shooting of single stage for competition.To make it slick lap in bolt and slick up buffer tube.You can also have a set screw installed to tighten up upper and lower.
    Keep your booger hook off the bang button!!!

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    Re: How to accurize an AR15

    An AR is not a bolt gun and the same tricks do not apply. My suggestion:

    1. Get a top notch barrel (hint Krieger)
    2. Get at top smith to chamber, put the barrel extension on and provide a matching bolt (hint WOA or CLE).

    Done.

    Get the best bullets you can afford and you'll be very pleased with the results. That's that beauty of an AR: it's pretty simple to create a shooter.

    PS. think of the bolt and barrel free-floating within the AR chassis. This is why all the other stuff is not as important. Of course, the barrel and optics must be securely attached to the upper, but that is a trivial task to get right.

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    Re: How to accurize an AR15

    Didn't see anyone mention to free float the barrel as well. Any decent handguard will work depending what your preferences are.

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    Re: How to accurize an AR15

    My question was answered;

    "There are a lot of things that can be done to an AR to enhance consistent accuracy, and I use the words "consistent accuracy" because consistency is a part of it (i.e. plenty of guns will give a couple great five shot groups with a break in between but won't do a very good 10 or 20 shot groups, and some guns will shoot great one day and not so good on others).

    Some items we think are important:

    1. A premium barrel, well machined with a good crown and a match type chambering, true to the bore and well cut, with the extension threads also cut true to the bore, and everything true and in proper alignment.
    2. A gas block that does not impose pointed stress on the barrel (i.e. clamp on types that grab all the way around the barrel are excellent). The blocks that are pinned on with tapered pins that wedge against the barrel or the slip on type of block with set screws that push up from underneath (or directly on the barrel) can deform the bore inside of the barrel and can wreck the accuracy of an otherwise great barrel.
    3. A heavy walled rigid upper receiver. The typical AR upper receiver was made for a lightweight carry rifle and they stripped all the metal they could off it to make it light to carry around all day (i.e. advantageous in military setting). The net result are upper receivers that are so thin you can flex them with your bare hands - they're strong but flexible strong - but not ideal for accuracy which does better with a more rigid upper receiver.
    4. Truing the face of the receiver. Some may argue this point but it is always best to keep everything related to the barrel and the bore in complete alingment with the bore (i.e. barrel extension, bolt, upper receiver, carrier, etc.).
    5. Loctite or glue in the barrel extension into upper receiver. This holds it in place all the way front to back in the upper receiver, otherwise if there is any play (and there typically is) it just hangs on the face of the upper receiver completely dependent on the face of the upper receiver as the sole source of support for the barrel as opposed to being made more an integral part of the uppper receiver by being glued in.
    6. A rigid free float hand guard (and I emphasize the word rigid). There are many free float hand guards and a free float hand guard is in and of itself is a huge improvement over a non free float set up, but best is a rigid set up. Some of the ones on the market are small diameter, thin and/or flexible and if you are shooting off any type of rest, bipod, front bag, etc., a rigid forend is best since AR's want to jump, bounce and twist when you let a shot go, as the carrier starts to begin it's cycle before the bullet exits the bore.
    7. Some meat on the barrel. Between the upper receiver and the gas block don't go real thin with a barrel (we like 1" diameter if it's workable weight wise). When you touch off a round and the bullet passes the gas port the gas system immediately starts pressuring up with a gas impulse that provides vibrations and stress on the barrel, especially between the gas block back to the receiver, a heavier barrel here dampens that. Correspondingly staying a little heavier with barrel contour through the gas block area and out to the muzzle is good for the same reasons. AR's have a lot going on when you touch off a round and the gas system pressures up and the carrier starts moving (all before the bullet exits the bore) so the more things are made a bit heavier and rigid to counteract that the better - up to a point of reasonableness of course).
    8. A gas tube that runs freely through the barrel nut and through the front of the upper receiver and through the gas key in the carrier is not impinged by any of them so that it does not load the carrier in a stressed orientation, nor is it bound up so that when the gas tube pressures up it immediately wants to transmit more force and impulse to the barrel than would normally occur. We spend a lot of time sometimes taking the gas block with gas tube on and off "new build" uppers and "tweaking" gas tubes to get that best (and most gas tubes need a little "tweaking" to get them right - factory tubes go in and they work but they are typically not optimum without hand fitting).
    9. Not over porting the gas port. Being over gassed makes the gas system pressure up earlier and more aggressively leading to more impulse, forces and vibration to the top end and barrel. Do what you need to function properly and adequately but no more.
    10. Front/Back bolt play (keep it .003" but no more than .005"). If accuracy is the game, don't leave a lot of front back bolt play. We've seen factory rifles run .012" to .015", which is o.k. if you need to leave room for dirt, grung, etc. like in a military setting out in the field, but not ideal for an accuracy build up. A lot of front/back bolt play makes it so rounds can be hammered into the chamber and actually re-sized and re-formed in a non-consistent way as they are loaded into the chamber.
    11. Use good parts from a reputable source and watch out with "gun show" specials. All parts are not the same, some are good and some are not so good, and some after market parts are not only not good, they are bad. Don't be afraid to use a mil spec type carrier either, by and large they are excellent for an acccuracy build up, and just because a carrier says "national match" or something else on it does not necessarily mean it's any better. Be careful of chrome plated parts as the chrome plating can change the parts dimensionally and can also make it hard to do hand fitting and necessary stoning for fit and function.
    12. A good upper/lower fit is helpful. For quick and dirty an Accuwedge in the rear helps a lot. The ultimate is to bed the upper to a specific lower (with bedding stuck to the upper but release agent on the lower) so that the upper and lower, when together are more like one integral unit. For the upper receivers we have made for use we try to get the specs as close as we can, but still fit the mix of lowers out in the market place.
    13. Don't screw up the muzzle (literally). Leave as much metal on the barrel at the muzzle as you can. People like to thread the muzzle for a flash supresssor, supresssor, muzzle brake, or some other attachment, but if you really want accuracy, leave as much metal as you can there and if you have something that screws on, set it up so that it can be put on and have it stay there without putting a lot of torque and stress on it right where the bullet exits the bore. If you are going to thread the end of the barrel, make it concentric with the bore and make sure what you screw on there is as well, and that the through holes where the bullet passes through are dead true to the bore (a lot of after market screw on things are not so good that way). Anything that vents gas should vent in a bilateral manner (i.e. if it vents left, it should vent equally right, and the for same up and down). Uneven venting of gas can wreck accuracy.

    There are some more items on things like chamber design, etc., but time is short for me now and this post encompasses most of the big ones."

    Robert Whitley
    www.6mmAR.com
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    Re: How to accurize an AR15

    wow................


    i thought i was at barf15dorcom there for a moment.....


    sometimes.....i quote myself, aand i'll say it agsain..."its all about barrels and triggers"


    there

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    Re: How to accurize an AR15

    Originally Posted By: BOLTRIPPER
    wow................


    i thought i was at barf15dorcom there for a moment.....


    sometimes.....i quote myself, aand i'll say it agsain..."its all about barrels and triggers"


    there

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    Re: How to accurize an AR15

    Thanks Robert, that is an excellent post!

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    Re: How to accurize an AR15

    Originally Posted By: LongArm
    Originally Posted By: BOLTRIPPER
    wow................


    i thought i was at barf15dorcom there for a moment.....


    sometimes.....i quote myself, aand i'll say it agsain..."its all about barrels and triggers"


    there

    Never miss a chance to shit on something.




    prove i'm wrong.........or maybe its just you being somewhat anal retentive

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    Re: How to accurize an AR15

    Originally Posted By: LongArm
    I am looking at processes to accurize the AR15 platform in the same manner gunsmiths accurize bolt actions. I am looking for insight into machining and truing the actions rather than the usual "buy a quality barrel and trigger" statements.
    Any input will help!

    Thanks,
    LongArm


    Read the first post? Like stated above you gave the usual answer that was not needed or wanted. I am not here for a pissing match. I wanted to know how to machine and true AR15 actions for accuracy as well as other things that will acquire accuracy.
    The democracy will cease to exist when you take away from those who are willing to work and give to those who would not. -- Thomas Jefferson

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    Re: How to accurize an AR15

    i guess there is no help for the handicapped....i mean really do you actually ever get out to shoot any of this stuff ??

    have you ever talked with and or seen anyone that got the score cards and national championships to see what they play with?

    re-inventing the wheel is your perogative and ....you may could do that but to what end.....

    this is all been done before by folks much smarter that you or i....and guess what.......or better put ...guess what it boilds down to........

    sometimes i quote myself......but i won't labor the point.,

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    Re: How to accurize an AR15


    "sometimes i quote myself......but i won't labor the point.,"

    But you are. Big talk over the internet. I am sure that you are "a big deal" and everyone values your frank opinions and sassy talk. You complain about "barf15dorcom" well guess what you are bringing this site one step closer to being just like barf15dorcom.
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    Re: How to accurize an AR15

    I'm confused.....you post on here asking a question then when you don't hear what you want you post your own researched answer and proceed to hammer everyone who tried to help.
    Still missing the point of this whole thread....

    Just saying...
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    Re: How to accurize an AR15

    Originally Posted By: Exhogflyer
    I'm confused.....you post on here asking a question then when you don't hear what you want you post your own researched answer and proceed to hammer everyone who tried to help.
    Still missing the point of this whole thread....

    Just saying...


    A ok, The question was never will a good barrel and trigger give you accuracy. It was for a more in depth answer. If you already have a good barrel and trigger what are processes that can be done to an AR15 to get more accuracy out the AR15.

    I searched and was given a link from snipershide which I posted. The link answered most of my questions so I posted it just in case it could help others.

    No "hammering" was given until boltripper jumped in with, oh this sounds like barf15dorcom. So if someone askes a questions and during the post finds the answer, posts it for others to see that's bad? Then you have people chiming in with smart ass comments (boltripper). I agree that a good barrel and trigger will give you good accuracybut I was not asking for that, which is clearly stated in the first OP.

    Anyone who replied I thank them, even if they stated that they believed that a good barrel and trigger was the way to go. I just don't like they way boltripper ran his mouth like he was king shit and who was I to ask such stupid questions. If I offended anyone who posted before boltripper I apologize.

    I am done with this part of the post. I only posted to hear input on machining and truing processes for accuracy and tips.

    Thanks,
    LongArm
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    Re: How to accurize an AR15

    A few years ago I was looking into building my own 1/4 moa AR. I called around to a few reputable builders including the company that built the first AR to win Camp Perry. He referred me to Robert Whitley. Long story short I bought a 6mmAR upper from Robert and put my own lower together. My best 5 shot group at 100yds was .115". Robert is VERY knowledgable about building an accurate AR and competes regularly, when he offers advice on accurizing an AR it is wise to listen! He was the builder I was quoting earlier
    Jesse

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    Re: How to accurize an AR15

    Originally Posted By: LongArm
    I am looking at processes to accurize the AR15 platform in the same manner gunsmiths accurize bolt actions. I am looking for insight into machining and truing the actions rather than the usual "buy a quality barrel and trigger" statements.
    Any input will help!

    Thanks,
    LongArm

    Accurizing an AR15 is very different from doing it for a bolt action rifle because they are different mechanical systems. The AR15 works well, in part, because some parts are loose on one hand, while on the other hand the bolt, receiver, receiver extension, and barrel lock up tight together.

    You should buy and read "The New Competitive AR15" by Glen Zediker. He explains what's important, why it's different than a bolt action, and how to accurize it or select parts that will make it accurate. There are a limited number of things you can do yourself, unlike a bolt action rifle.

    He has a new book on building your own AR15, step by step. I'm going to order it myself.

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    Re: How to accurize an AR15

    Mr. Whitney's explanation was an interesting read.

    Boltripper raises points more germane to this site.

    The questions in my mind are:

    1. With respect to Mr. Whitney's methods - has Mr. Whitney or others that subscribe to the same ever taken just a good barrel / FF / and a good trigger - worked up a load, shot it for accuracy; and then made the rest of the changes, used the same load and recorded the results? (Or better yet made individual changes and recorded the results for each change?)

    2. The blocks that are pinned on with tapered pins that wedge against the barrel or the slip on type of block with set screws that push up from underneath (or directly on the barrel) can deform the bore inside of the barrel and can wreck the accuracy of an otherwise great barrel

    Can this be expanded on? Deform the bore? You mean change the physical shape of the bore? I'd like to hear more about this. In fact - I'd love to see a photo, b/c the only way I can conceptualize this happening is that the bore is breached when drilling the hole for the taper pin and pin then becomes part of the bore - thus deforming it or altering the dimensions. Related and follow up question - would you say this is more of an error on the part of the builder and that it is a rare anomaly, or that it is a common issue with pinned blocks?

    Pinned blocks have the advantage of being much less likely to come loose in austere environments.



    Good luck
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    Re: How to accurize an AR15

    Originally Posted By: Mo_Zam_Beek
    2. The blocks that are pinned on with tapered pins that wedge against the barrel or the slip on type of block with set screws that push up from underneath (or directly on the barrel) can deform the bore inside of the barrel and can wreck the accuracy of an otherwise great barrel

    Can this be expanded on? Deform the bore? You mean change the physical shape of the bore?


    The clamp-on gas blocks avoid creating a stress-point on the barrel. The pinned blocks don't actually "deform" the barrel but instead create a stressed area which can impart a "bump" in the bore and/or alter the barrel's response to the shock wave of the bullet and gasses passing through it.

    Match-grade barrels are usually completely (or as close as they can get them) releived of any stresses created by the boring and rifling processes. Most top 'smiths do everything they can to prevent any outward stresses being placed on the barrel when mounting in the chassis.
    X's are great but 10s are what wins.

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    Re: How to accurize an AR15

    Originally Posted By: LongArm
    Originally Posted By: LongArm
    I am looking at processes to accurize the AR15 platform in the same manner gunsmiths accurize bolt actions. I am looking for insight into machining and truing the actions rather than the usual "buy a quality barrel and trigger" statements.
    Any input will help!

    Thanks,
    LongArm


    Read the first post? Like stated above you gave the usual answer that was not needed or wanted. I am not here for a pissing match. I wanted to know how to machine and true AR15 actions for accuracy as well as other things that will acquire accuracy.

    And you have a good answer from Whitley. ARs are capable of shooting under .2 if they are built right most just don't know what it takes and most just blast at computers or beer cans, anyway you have your answer.
    Does your daddy tell you what to post here? Then who gives a shit what he does?

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    Re: How to accurize an AR15

    Anything that squeezes or stretches the barrel creates stress, when the barrel heats the barrel will react to stresses and make shots walk. Clamp gas blocks are better than set screw blocks but there are some that require nothing more than a little loctite and the close tolerance they are machined to.
    I think most think of an AR as a combat rifle where a pinned gas block or F sight base may be important, it doesn't take much to make a rifle combat accurate but when you are looking for 1/4MOA consistently for a long range comp rifle there are things that should be done.
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    Re: How to accurize an AR15

    BoltRipper....13766 posts......dude......get a girlfriend!

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    Re: How to accurize an AR15

    Originally Posted By: Killshot44
    Originally Posted By: Mo_Zam_Beek
    2. The blocks that are pinned on with tapered pins that wedge against the barrel or the slip on type of block with set screws that push up from underneath (or directly on the barrel) can deform the bore inside of the barrel and can wreck the accuracy of an otherwise great barrel

    Can this be expanded on? Deform the bore? You mean change the physical shape of the bore?


    The clamp-on gas blocks avoid creating a stress-point on the barrel. The pinned blocks don't actually "deform" the barrel but instead create a stressed area which can impart a "bump" in the bore and/or alter the barrel's response to the shock wave of the bullet and gasses passing through it.



    Hmmm.... so it isn't "deformed" but there is a 'bump'... sounds quantifiable and definitely something that could be verified by photography - again - can I see some pics and review some data?

    BTW since you aren't the OP of the original "Deform" statement - are you a trained gunsmith making a living from the same? Or are you a garage builder?


    Good luck
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    Re: How to accurize an AR15

    For those of you concerned about clamping gasblocks, as long as they are the single split clamping style, they have VERY good holding strength. You will not be able to knock them out of alignment. The force required to knock them out of alignment, would trash the rest of the rifle.

    Just look at the Military Morons post on the Vltor VST-1C where he welds a 1/2" driver socket onto the gasblock and applies enough torque to shear the index pin in the upper. The clamp didn't move through this test.

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    Re: How to accurize an AR15

    Good read, I learn something new everyday.

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    Re: How to accurize an AR15

    Originally Posted By: Scooter-PIE
    BoltRipper....13766 posts......dude......get a girlfriend!


    AGREED! I have seen more "5 words or less" posts from him and they rarely seem to be related to the original post.

    I, for one, would like to thank you for posting this information to help better educate some of us. I do not buy into the "ultimate AR accuracy in a bottle" by just adding a barrel and trigger.

    If bolt fit didn't matter why would any bolt action have the lugs lapped on the bolt? Once the boly and lugs are locked and engaged into the reciever or barrel extension it is a singular, hopefully concentric with the bore, piece. if the bolt is canted or the bolt face is canted to the bore then so will the cartidge on it's start into the chamber.

    Benchrest actions tend to be some of the beefiest that there are! because they are stiff. If you have a bolt that rides in a bore that can easily be torqued and flexed then you will lose concentricity with the bore and your accuracy will suffer....Period.

    Yes, a kreiger, hart, shilen, etc. will shoot better than your run-of-the-milspec barrel due to metalurgical superiority and extremely tight machining tolerances. A timney, Chip McCormick, Riflebasix, etc. trigger will break worlds better than the feels-like-sand-in-Tw@t mil-spec junk.

    Are these the only things that matter?....Absolutely not! if this were the case with harmonics, machining tolerances, metal fatigue, and concentricity with the bore then everybody might as well just throw away their AICS 2.0's, buy the best trigger and the best barrel on the market, forget about free floating the barrel on your Rem, Savage, Sako, etc. Don't even think about bedding the action to the stock let alone torquing the action screws and GOD FORBID that you had the bolt lugs lapped on your Rem 700.

    A rifle is a system.

    The trigger must break cleanly and quickly with a very short lock time and the rifle should remain pointed at the target throughout this happening.

    The firing pin should strike the primer and ignite the powder inside the case that should be in an exactly centered chamber (this includes the bolt face to the rifling and everything in between).

    The barrel should have as little stress as is possible by any outside influences (this is why it should be free floated, of large diameter, and be attached to an as ridgid as possible upper reciever) the barrel will contain harmonic vibrations from the firing of the cartridge (look up ladder test) the barrel will flex under these vibrations and these will travel throughout the entire rifle.

    Taper pins that have been machined into the barrel (that from the manufacturer should be stress RELIEVED!) once driven in have a very large amount of force imparted into the metal surronding the holes that have been drilled for them; guess what differing stresses and grain structure does to vibrations traveling through the barrel!? This is a situation that is best to be avoided....just clamp it and go as far as a FSB or gas block is concerned.

    Once the bulet leaves the beautifully smooth and mirror finished bore of your top notch barrel the resulting gasses of the propellant will dissipate directly behind the bullet. If there are any stresses in the muzzle of the barrel it will already leave the bullet in a less than perfect state of stability. Now if we wanted less than perfect stability would we have bought a top of the line barrel!? These gasses must vent evenly in all directions or this will cause the bullet's base to be forced out of the concentric line of the bore. The break should be inline with the bore and should impart as little stress as is possible into the muzzle. After all of this has been done the happy little, or big, bullet should be spinning on it's way torward the intended target, that the rifle should still be pointing at, and geared up for its impending doom in the backstop.

    The above is for those who NEED reasons (or if boltripper should want to question why on this I won't have to sit down and type all of this up later)

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    Re: How to accurize an AR15

    Originally Posted By: BOLTRIPPER
    wow................


    i thought i was at barf15dorcom there for a moment.....


    sometimes.....i quote myself, aand i'll say it agsain..."its all about barrels and triggers"


    there


    Way to fuck up the thread with your narcissistic, ego stroking bullshit after Robert's truly excellent post. Do you feel better now? Since English obviously isn't your forte, at least you're good at ruining threads.

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    Re: How to accurize an AR15

    resurrecting in this thread.

    Well I bought another AR in 308. I am thinking about trying to bed the upper. Does anyone have any pics on how this is done? I have seen some pics from the web but who knows if it was correct or just a guess.
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    Re: How to accurize an AR15

    I finally did my own bedding job on a DPMS/Bushmaster LR308 (AR10 type). I wanted to post it here because when this all started this is where I posted my questions, so here is a link.

    How to bed an AR10/AR15
    The democracy will cease to exist when you take away from those who are willing to work and give to those who would not. -- Thomas Jefferson

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    Re: How to accurize an AR15

    Your bedding job is nice for mismatched upper and lower fit but really has no part in accuracy improvement.

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    Re: How to accurize an AR15

    What recommendations for a "heavy walled rigid upper"?
    Judges 6:12-16 The angel of the LORD said to Gideon, "The LORD is with you, mighty warrior." "But Lord," Gideon said, " how can I save Israel? I am the least in my family." The LORD answered, "I will be with you."

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    Re: How to accurize an AR15

    i vote for a quality barrel, and then a good trigger
    KACHI KAPSHIDA

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    Re: How to accurize an AR15

    Originally Posted By: Jerub-Baal
    What recommendations for a "heavy walled rigid upper"?


    The bolt locks into the barrel itself. Stiffening the receiver doesn't really do anything.

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    Re: How to accurize an AR15

    Originally Posted By: BCP
    The bolt locks into the barrel itself. Stiffening the receiver doesn't really do anything.


    True enough about the bolt locking to the barrel but a more flexible upper will result in greater barrel movement with a possible reduction in accuracy.
    Judges 6:12-16 The angel of the LORD said to Gideon, "The LORD is with you, mighty warrior." "But Lord," Gideon said, " how can I save Israel? I am the least in my family." The LORD answered, "I will be with you."

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    Re: How to accurize an AR15

    I don't vote for any of the above. I vote for you to go out and shoot till you puke.I use a "68" SP1 and have never had a accuracy issue because case after case of ammo I learned how to shoot that platform. And I am still learning. To many times I have seen people come into the shop and want to buy the most accurate gun that I can get them only to figure out the person has never shot one time with the gun he is buying let alone over a hundred yards EVER! I go out with guy's all the time with the latest crap magnet rifle and shoot like shit because they never spend good time behind the trigger.

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    Re: How to accurize an AR15

    I like the informative parts of this thread. To address the issue about pinned blocks. I remember reading Bill Calfee on slugging bores of rimfires. He has demonstrated that he can feel the area where a barrel is stamped with name cal etc. Also, remember that the 40X BR rifles are etched on the action and barrel. If slight stamping causes changes on the inside, a wedged pin block sure can.

    True precision is beyond the area of interest and ability to comprehend of most humans, including many on this site. To bad they can still type and post, when they have nothing to say. Or worse yet, the guy who specilizes in vulgarity in any post and his sig as well. A waste of 02.

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    Re: How to accurize an AR15

    Originally Posted By: smschulz
    Your bedding job is nice for mismatched upper and lower fit but really has no part in accuracy improvement.


    Thanks, I agree but it was not done for an accuracy improvement. That was stated twice in the first paragraph of the link I posted.

    However if the accuracy was improved I would not complain. It was done more to fix the slop in the upper and lower. I had never done it and figured it'd be fun to do.
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    Re: How to accurize an AR15

    Vltor stiff upper. Rifle or at least mid length gas system. Quality barrel and get the gas tub with the barrel from the manufacturer. They know what they can do with their gas blocks and keep accuracy. Geissele SSA TRIGGER.

    Been there , done that, got sub MOA , oh yea 69 grain SMK's.

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    Re: How to accurize an AR15

    Thanks for all of the info guys!

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    Re: How to accurize an AR15

    Longarm....thanks for putting up Robert Whitleys very interesting info on his techniques. Your question is a really good one and you are right...it is seldom thoroughly addressed.

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    Re: How to accurize an AR15

    Thanks. I knew that there had to be something that could be done to get more out of the AR platform. There is always something that can be done. If you asked most people they will say that the AR platform is not known for its accuracy. This is because no one expects that much out of them. Look at how much goes into a bolt action. If you were put to that amount of time into machining and tweeking an AR then it to will be accurate.
    The democracy will cease to exist when you take away from those who are willing to work and give to those who would not. -- Thomas Jefferson

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    Re: How to accurize an AR15

    When I'm venturing to build an accurate AR, I try to make sure that everything is true and also try to make sure that there aren't going to be (how can I say this?) stresses that are going to vary as the barrel heats up.

    I know that many like to think that an upper is an upper. I don't agree, not when building for accuracy. I've seen groups tighten up by .5 MOA just by replacing the upper receiver. Not all upper receivers at created equally. I've had the best luck with Daniel Defense uppers. They seem to hold to tighter tolerances than most no name brands, or even the likes of Rock River or DPMS. I just have faith in the receivers and have had good results with them.

    I also think that it is important to lap the face of the receiver so that you get a good fit between the receiver and barrel extension. I also be sure to use an barrel receiver combo that is almost a press fit. I never use a combo that exhibits a very loose fit.

    These are just a couple of things that I watch out for. I really don't think that there's a whole lot of voodoo to building an accurate AR.

    One thing that I do not do, is try to tighten the fit between the upper and lower. Like I said, I like to avoid stresses as things heat up. I've built several ARs that shot half MOA consistently. Maybe my recipe means something and maybe I just got lucky.

    And...I've also used the best barrels and triggers that I could get.

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    Re: How to accurize an AR15

    LongArm is right.

    Think about the process that any of the builders here go through when working on a bolt gun for you guys?

    They true the internal lugs of the receiver (making them nice and flat and perfect) then they true the bolt lugs. Now you have two "perfect" surfaces against each other.

    Then they go after the back of the barrel.

    Basically, they true every mating surface and make it nice and tight.

    If you were to true the lugs on an AR-15 barrel extension, make sure the threads are cut perfectly, and make sure the back of the barrel is cut flat and parallel to the extension lugs, and then machine the bolt to have the same surfaces, and set the headspace right, you could easily tighten up what a AR-15 can do.

    As with anything mechanical, the more time and effort you put into building it, the better it will be.

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    Re: How to accurize an AR15

    Good point on making sure the receiver to barrel fit is nice and tight, and yes, truing the front of the upper receiver to the barrel will help.

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    Re: How to accurize an AR15

    The 1990's called: They want their topic back. [img]<>/grin.gif[/img]
    http://www.amazon.com/The-Complete-G.../dp/0967094844

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    Re: How to accurize an AR15

    Steady...Aim...Fire...

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