Subsonic Brass Prep Question

BearNaked

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Feb 13, 2017
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#1
I am going to venture into some subsonic loads for shits and giggles. Came across some stuff that I saw different opinions on.

Do you need to open up the flash hole or is this more of a theory that doesn't really do much? if it does do something significant, what happens if it got mixed up with a full powder charge load?

Magnum primer vs Standard Primer?

Flat base round nose bullets seem to be what works best and for the life of me I cant figure out why. Will the BTHP's work just as well?

Im going to try out the 143 ELD-X to see what happens in my 260 rem.
 
Apr 25, 2008
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wilds of montana
#2
Well opinions are like a-holes. Everyone has one and everyone else stinks. I have no experience with the 260. I have spent a fair amount of time with a 308 this past year. I do not open up flash holes. I do uniform my brass to include annealing. Standard primers are fine. Contrary to many I use Red dot. Started out with trail boss,btdt now. Flat bases have worked better. I mostly shoot cast now, being a cheap btard I smile at those nickel a piece shots.
A chrono is your friend. Remember start a little fast and work backwards. There are a couple of threads here but no one has posted on them lately.
 

BearNaked

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#3
Thanks Cav. Yes they all stink. haha.

I read all the threads on this dating back to 2011 but none really said anything about whether opening up the flash holes was a must or just one of those things that makes people feel better about doing. I have seen some people use 700X and other pistol powders. since this is just going to be a paper killer round and maybe some rabbits for fun, I wasn't going to try to get super accurate with it. 1moa will work for me.

Do you use any fillers with the red dot or it works fine as is?

I have some of the 143's that didn't shoot that good in my rifle so I was going to try those first since the money was already spent on them. I will look at the round noses later on once I run out of these.
 
Apr 25, 2008
709
41
28
wilds of montana
#4
I use no filler. The Red Dot load is not position nor temp sensitive. I am lighting it off with Winchester large rifle primers that are likely 50-60 years old. Attention to brass seems to be fairly important when stretching your target distances. If I were trying to run a 6.5 with jacketed bullets I would try and find some Swede surplus I think they were in the 170-175 gr. range. If they would stabilize They would hit pretty hard. For paper that maybe a non issue though.
Good luck with your endeavors.
 
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BearNaked

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#5
Will do. I was looking at the 160 RN that hornady makes for when these dry up. ill be on the lookout for those as well.
 
Oct 29, 2008
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#6
Yes, there are lots of opinions on this subject. I did A LOT of research and testing when I had an AI Covert w/Suppressor and here is what I came away with for the .308:

-1.) Start w/high loads and work your way down
0.) ALWAYS test WITHOUT the suppressor at 100 yards to verify stability before testing with the suppressor
1.) Tried opening flash-holes ... did not make a difference
2.) Tested magnum primers as recommended to make sure to get good ignition - made loads MORE erratic
3.) Aim for a velocity no faster than 1,020 fps as it too easy to get "flyers" that go trans-sonic or super sonic
3a.) shoot the heaviest bullet you can stabilize at 100 yards
3b.) shorter bullets are easier to stabilize than longer bullets
4.) Speed of sound will vary based on temp, DA etc. and if you are near the transonic range of 1,080-1,100 fps things get louder and less predictable
5.) Seemingly small changes can sometimes produce large (and unpredicted) results ...
6.) Primers make a BIG difference
7.) Trailboss works well
8.) TinStar works well
9.) Vhit N310 works well
10.) Consider using Lapua's Subsonic FMJ bullet for .308 ... these work well and are optimized for the task. They are short, 200 gr, and bore-riders, otherwise I have found 190 SMK and 200gr SMK to work well in 1:10 twist barrels as well as 220gr RN.

11.) Shooing a deer at 110 yards with a sub-sonic 220gr RN is like walking up to them an putting a .45 ACP to their head and pulling the trigger ... they just drop ... and all the other deer just stand around.

12.) it IS possible to come up with a sub-sonic .308 load that shoots 1/2-3/4" MOA (5 shots) at 100 and 200 yards ... but it requires A LOT of work and patience ... A CHRONOGRAPH IS YOUR FRIEND ...

13.) .260 maybe more challenging as they shoot longer bullets but you might be OK as you start with a faster twist rate.

14.) The only brass prep you need is to color (with a sharpie) the bases so you don't take the wrong box of ammo to a match or a hunt ...

Have fun ...
 
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#8
I am going to venture into some subsonic loads for shits and giggles. Came across some stuff that I saw different opinions on.

Do you need to open up the flash hole or is this more of a theory that doesn't really do much? if it does do something significant, what happens if it got mixed up with a full powder charge load?

Magnum primer vs Standard Primer?

Flat base round nose bullets seem to be what works best and for the life of me I cant figure out why. Will the BTHP's work just as well?

Im going to try out the 143 ELD-X to see what happens in my 260 rem.
Having been into subs for 25 years now I'll tell you what I know as fact for my .300wm/.308/.223
I do not use jacketed bullets at all, there is too much variance in the bearing surface's which effects SD/ES.
Subs are harder to load for small groups at long than H/S projo's
Bullet nose design vs twist rate has to be watched, bullet weight means nothing except on target performance.
Primer pockets do not need to be opened, nor the use of mag primers.
Fast burning pistol powder is more finicky with jacketed bullets vs cast. 700X is the most consistent for me with Clays second, but I have to weigh both as my thrower jams up with them. Red Dot is my std playing load, but when it has to be in the eye 700X gets used, but those have to be weighed.
BTHP's will work but only in faster than normal twist rates for the cal. I run a semi pointed to 600 yds leaving the muzzle at 1080fps an they get there point on, in less than 1-2.5moa groups if you can read mother, an depending powder used.
I do not use a dedicated smoke pole for subs, I have subs for everything. The 300wm an .308 leave the muzzle at the same speed so there is no different up numbers to remember past the difference between H/S an a sub in the same weapon. In my .308's there is 13-15moa (depending temp)of up needed to be POA/POI over my H/S zero(same weapon) an 1.5 moa of left wind for S/D. In my 300wm it's 14-16 (depending temp) an 1.5 left wind for S/D. The S/D(any weapon) stays the same until about 250-275 yds then I have to start adding more left wind as I shoot longer. Different cast bullets will drift different in all my sticks. There is very little difference in up past 100yds in my 300wm vs .308 as the bullet is the same, but the mechanical off set is different.
Remember it's not what you hit them with it's where you hit them at. Knowing the targets anatomy/weakness is king on live targets with subs.

I bought into all the internet hype about sub ammo for a long time, until nothing was working like I thought it should. So I went rouge an the trial started. We now have sub only shoots, an have learned much about what works an what is pure internet B/S. Get you ammo down, then start learning to read mother nature ( temp/wind/%h20). I shoot 10-20X as many subs as H/S now, an deer sized targets are give me, much like a shotgun to rabbits, using them.

I run a Lyman semi pointed cast bullet(311332BV) using wheel weighs an a gas check. The total weight is 193 grs (lube & gas check) Using the gas check there is no leading, an the first shot or the 100th is in the same place even when switching between H/S an subs.
Hornady is the only gas check I use as most all the others are designed to leave the bullet at the muzzle, bad news for a can. The Hornady has a locking ring that grips the bullet, an when on correctly will not come off even when impacting steel.
Some say a .223 sub is worthless an mostly are past 250 yds but, they will kill deer to 100yds as well, however shot placement is key.
 
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#9
From limited experience with .308 and .223:
-regular flash holes
-I use a mag primer, but can'ts say that it matters
-flat base bullets grouped significantly better with 55gn 1/9 twist .223. But not really noticable group wise with 180 gn 1/10 twist .308
-Gemtech say only Engel Ballistics Reseach ammo is approved for subsonic rifle use in their cans for warranty. Stable at 50Y may actually have some yaw as it exits the muzzle, so need to test at 10yds to ensure stability. EBR uses flat based hunting type bullets for shorter bullet, less yaw, etc. Something to at least consider.
-Hogdon has load data for Titegroup for .308, so maybe a powder to consider.
-I use WC-820 (from .30 carbine or .357 MAG relaoding) for .308 and Titegroup for .223, so lots of powders will work
 

BearNaked

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#10
ok so everything worked perfectly with normal brass prep. next question, at what distance do I verify stability before putting on my can? 10 yards, 50 yards, or is 100 yards ok?
 

BearNaked

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#14
I have thought about doing those, I will just need to find a source for lead but that does seem to be the way I will more that likely head.

do you get good expansion on solid lead projectiles? I may try to do some hunting with these only if I can get good expansion. If I do end up hunting with them then It will only be within a 100 yards. anything past that will be getting a full power load to the face.
 
#15
No they will not open up much if at all depending hardness but, they don't need to when placed right. I kill deer/yotes with 223 subs w/o issue but, shot placement an range has to be factored in. Bullet expansion is a hold over from the early days of smaller projos traveling fast equaling bigger slower projo's, but w/o the drop. Remember it's not what you hit them with, it's where you hit them at. Subs will put all the meat on the table one can eat an then some, but field-craft as to be better than average.
 

BearNaked

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Feb 13, 2017
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#16
No they will not open up much if at all depending hardness but, they don't need to when placed right. I kill deer/yotes with 223 subs w/o issue but, shot placement an range has to be factored in. Bullet expansion is a hold over from the early days of smaller projos traveling fast equaling bigger slower projo's, but w/o the drop. Remember it's not what you hit them with, it's where you hit them at. Subs will put all the meat on the table one can eat an then some, but field-craft as to be better than average.
agree 100%. I care more about shot placement than anything else. I just prefer expansion for a better kill. I'll give it a shot sometime and see what happens. mine loads are still producing a 1 moa group at 100 which in my mind isn't bad for subs.
 
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