6.5 Grendel more or less dead?

hlee

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I guess that depends upon what you want the mag to do. Here are some measurements from the mags that I have on hand...

ASC 10 round mag- 2.317
Elander 10 round mag- 2.290
AA (Elander) 17 round mag- 2.290
AA (Elander) 24 round mag- 2.290
 

5RWill

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I'm just trying to get 123gr SST to 2300fps in mag length out of a 12.5" grendel. Factory ammo is close to that. Probably seat at the cannelure and crimp
 

Yondering

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Got 4 new 10 round ACS mags. I can fit 2.280" no problem. As you indicated, 2.290 ish is about as far as I would go. Turns out my problem was with some VERY old 5-round CProducts mags. Must be the damn 5 round limiter that does not allow for proper stacking/compression. Strange. My old 30 round mags seen t be GTG out to these lengths. Mystery solved.
So a heads up on ASC mags - the straightness of the front of the mag (where the two layers overlap) varies a bit, and if yours are maxed out at about 2.290 you may have a shorter batch. Sometimes the inner layer is bent slightly inwards, if so I'd ask ASC to replace them.

If you can actually do longer and are just saying 2.290 is max for reliability, that makes sense and sounds about like mine. I just like to leave a little clearance in there.
 

Yondering

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I'm just trying to get 123gr SST to 2300fps in mag length out of a 12.5" grendel. Factory ammo is close to that. Probably seat at the cannelure and crimp
That's pretty easy with a number of different powders, unless you just have a slow barrel. 8208 and IIRC H4895 will do it, as well as several ball powders like CFE223, TAC, and Lever which all do that fast easily without pushing the limits.

My 12.5" go-to load is the 123 ELD-M over 8208 for 2340 fps, that's a comfortable accuracy load not a max brass-killer load. Work up to something like that and then tune your OAL for accuracy.
 

5RWill

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That's pretty easy with a number of different powders, unless you just have a slow barrel. 8208 and IIRC H4895 will do it, as well as several ball powders like CFE223, TAC, and Lever which all do that fast easily without pushing the limits.

My 12.5" go-to load is the 123 ELD-M over 8208 for 2340 fps, that's a comfortable accuracy load not a max brass-killer load. Work up to something like that and then tune your OAL for accuracy.
I've got plenty of 8208 though i really wanna try Staball because i could throw it and load faster.
 

bobke

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Think StaBall is going to be too slow for Grendel. 28.0-28.2ish of 8208 or 31.0-31.3ish CFE223 should put you in ballpark. 27.2 of AR Comp has worked very well with 123 Sierra, very accurate, but perhaps not the speed you’re looking for. CFE pours like water, 8208 and ARC show more variation from Redding throw. Am about to head out to ranch with 24” Satern and 129ABLR’s-we’ll see how that shakes out. 2500fps/9.8 SD.
 
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Greg Langelius *

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The 90gr Varmageddon looks very good, but will have to wait.

For now, my testing will continue with the 90 TNT and 95 V-Max, followed by the 123 SST. I have a ton of 90 TNT's.

So many choices, so little time.

Will get to it, but probably not before the end of this year.

Greg
 

AZgeek

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Did some velocity testing couple of years ago with 556, Ramshot TAC beat out CFE223 for the 75gr class bullets. Not sure why its not as popular these days for the Grendel.
 

Nimothy

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I've been on the fence about an AR build and up until recently my caliber of choice was going to be Grendel.

Seems like a lot of the hype for the caliber has diminished, and with the announcement that the Army will be moving to 6.8 I think I may switch.

I reload, but I availability of surplus ammo for plinking and harvesting brass is a consideration, so if Grendel is on the way out I'm not sure I want to jump in.
I feel the same way. I’ve been dreaming of a 12.5 upper for my registered lower. But now I’m thinking. A lot of my friends who are really into night time hog hunting have ditched their scars in favor of a lwrc 6.8. Maybe that should tell me somthibg
 

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I'm using W748 and WSR primers for the 6.5 Grendel.

It's listed with loads for Hornady bullets in the latest (10th) edition of their loading manual.

It's fine grain Ball/Flake powder and meters very smooth in my RCBS Chargemaster Lite.

With an arbitrary ballpark load it's shooting 1 1/4" at 100yd in both my 20" and 24" AR15 Upper using 90 TNT and 95 V-Max. Incremented loads testing will likely commence this coming week. The only holdup is some serious rain until this Friday.

After finding the best increment, a final test will be made substituting CCI BR-4's.

Greg
 

5RWill

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I feel the same way. I’ve been dreaming of a 12.5 upper for my registered lower. But now I’m thinking. A lot of my friends who are really into night time hog hunting have ditched their scars in favor of a lwrc 6.8. Maybe that should tell me somthibg
Both a buddy and i went 12.5" grendel for night setups for hogs. To me there is no reason to go 6.8 less drastically reducing the barrel length. BA has been sold out of those barrels for months so i really don't think it's dying. Bullet and brass selection alone for the grendel is enough to sway me away from 6.8spc. There's just something about a 12.5" grendel with a 123gr SST @ 2300fps that screams versatile SBR. It crushes a full size AK with the same weight 7.62x39. I know lots advocate the 6.8 SPC for SBR setups but i honestly don't see the grendel losing that much to it in setups above 11.5"
 

Nimothy

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Both a buddy and i went 12.5" grendel for night setups for hogs. To me there is no reason to go 6.8 less drastically reducing the barrel length. BA has been sold out of those barrels for months so i really don't think it's dying. Bullet and brass selection alone for the grendel is enough to sway me away from 6.8spc. There's just something about a 12.5" grendel with a 123gr SST @ 2300fps that screams versatile SBR. It crushes a full size AK with the same weight 7.62x39. I know lots advocate the 6.8 SPC for SBR setups but i honestly don't see the grendel losing that much to it in setups above 11.5"
Good to know, and you’re right I check ba about once every 2 weeks to get one their premium 12.5 barrels
 

Constructor

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Does it work better though? I know it works. It’s a mean round for the application.
It shoots the same weight bullets out of the same length barrels apx 100fps faster using Hornady ammo for each. If you handload the 6.8 will gain more difference since the 6.8 can handle more pressure without bulging the cases or breaking bolts. There are more USABLE hunting bullets that expand properly at the velocity the 6.8 can propel them, 130gr and under. Many of the heavier 6.5 bullets were designed for the 6.5x55 and 260 Rem, they will not expand at a distance after they slow down. 6.5 has the advantage when it comes to target/match bullets.
It seems many like to think that SD plays a difference in penetration on game but after the bullet expands the SD changes so the published SD # is useless when it comes to penetration on game. The only time SD would be valid is if the bullet never deforms like a solid used on big game in Africa.
If you have a 6.5 there is no need to buy a 6.8, If you have a 6.8 there is no need to buy a 6.5...for the purpose of hunting.
 
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brazz04

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If you have a 6.5 there is no need to buy a 6.8, If you have a 6.8 there is no need to buy a 6.5...for the purpose of hunting.
A solid statement there from a guy who builds barrels for both cartridges. I have a 12.5" 6.8 from Constructor and a 14.5" 6.5 from Precision Firearms and I absolutely love both from a hunting and as well as a target shooting perspective.
 

Yondering

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Did some velocity testing couple of years ago with 556, Ramshot TAC beat out CFE223 for the 75gr class bullets. Not sure why its not as popular these days for the Grendel.
One powder being faster in 5.56 doesn't mean the same is true in the Grendel. However, TAC is still a good and popular choice for the Grendel.
 

ssdrew

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I'm pushing a 120gr Speer Goldot at 2300fps out of my 12.7 with AR-comp. It's a fairly moderate load. I think I'm going to pick up some Starline brass and play around with some powders to see how fast I can push it.
 

Greg Langelius *

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My second Grendel outing was Friday. I noted two bonehead mistakes of my own.

First, the 1 1/4" grouping (at best) for 100yd previously experienced was being done with an M-Lok bipod mount whose screws were contacting the barrel. Ikk! No wonder the factory stuff (AE 90 TNT and HDY Custom 123SST) shot poorly. The Bernaul was about 8" at 100.

Removed that mount and the groups suddenly shrunk significantly (off the rest and concrete bench).

But Lady Luck still was not smiling at me.

Many/most of the test rounds were not chambering. I had made up handloads from once fired brass, and had assumed that I'd set up the F/L die properly. I had forgotten that new brass was already short. The newly resized actually fired brass was about the thickness of a piece of paper longer than the case gauge max.

How that got by me can only be ascribed to complacency (and senility?).

Back to the loading bench for me,.

FYI, the Upper in question is a handmade-from-AR Stoner-parts-exclusively item with the 24" AR Stoner barrel. The receiver was faced and the barrel extension was bedded with Red Loc-Tite.

Friday's outing produced tighter groups at 100yd, but the constant chambering problems probably invalidated any genuine ability to count them as 'real'.

The brass is Starline, the bullet is 90 TNT, the powder is W748, and the primer is WSR. The charges were 29.4gr *, 29.7gr, 30.0gr, 30.3gr *, and 30.6gr. The asterisks indicate the loads with apparent promise, but this test really does need to be redone with more properly spec'd ammo. There are also supposed to be test loads using the 95 V-Max at the same charge increments.

The Lowers are the PSA M4 Classic with the above mods. The other Grendel Upper is a factory built AR Stoner 20".

As data on both become more reliable, I'll keep you all apprised.

Greg
 

Greg Langelius *

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F/L die is readjusted, fired/resized brass from second outing now agrees with case gauge, more on the longer side than short. I'm trying to keep brass working at a minimum.

Bipod mount fixed. Mounted it up, loosened it enough to remove from handguard, then ground the protruding screw down flush with the mounting shoe. Remounted, resulting clearance w/barrel appears to be 1/8" or a smidge more.

The handguard is especially slim. This is the homebuilt-from-AR Stoner-parts 24". The factory 20" AR Stoner Upper has a slightly bulkier handguard and no clearance issues are apparent.

Speer 6.5mm 120gr Gold Dots (300 Count) are in. The boattail is rebated like the Lapua; best I can find is that this is the exact "protected point" bullet used in the Federal Fusion MSR 6.5 Grendel 120gr load. Federal and Speer are both members of the same manufacturing group.

Federal literature/posting indicates a 2600fps MV, which is mighty quick. It's hard to tell what length barrel is being used to obtain that velocity. I'll be using 20" and 24" to develop the load. I'll be loading W748 and arbitrarily setting 30.0gr as the initial max for testing. I believe that this load will be a generally good all around package.

Not looking for maximum velocities; accuracy is the goal. Will only be clocking velocities after load development, solely to establish MV for trajectory plots.

The 90 TNT test loads will be retested, with emphasis on the 29.4gr and 30.3gr W748 loads that appeared promising in the first run-through.

For now, test loads are primed with WSR Primers.

All brass/primers from that run showed no/zero indications of excessive pressure.

Greg
 
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AZgeek

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I have some older 120gr Speer Hot-Core bullets I tried last weekend. 5-shot group was just under an inch. .9" to be exact.
 

Greg Langelius *

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The Internet seems to think these are the new Hot-Cors.

They feature inside skiving with the protected point. The photos of recovered kills are very impressive.

If they are, as I suspect, the same bullet used in the Fusion MSR loads, it's reported as very effective in terms of terminal performance.

I've also read many favorable comments on the accuracy; I'll be working to get my best with the 20" and 24" Uppers.

Midway's currently selling them at $.28 per bullet, and I'm stocking up.

When I'm done with the Grendel project, I aim to try these out in my 28" .260 with a stout load of H-4831; it absolutely loves 120gr Nosler BT's. Imagine a 120 at about 3000fps, and without a plastic tip. At 4350ft ASL.

Forget about the ELD-X.

Greg
 
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AZgeek

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Yea they are not the same. I believe the hot-cores were discontinued quite a while ago. They claim the gold dots are "self-defense" bullets. Not sure what to make of that, but I've read they are very accurate.
 

Yondering

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F/L die is readjusted, fired/resized brass from second outing now agrees with case gauge, more on the longer side than short. I'm trying to keep brass working at a minimum.
Why are you checking with a gauge instead of measuring against your chamber?

I get it for a 3 gun match or something high volume like that, but for what you're doing?
 

Greg Langelius *

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I like to have the checking taking place out in the open where I can see what's going on.

But mainly, when the symptoms appeared, the case gauge agreed there was something wrong. I kicked myself for assuming something I should have been checking against a known standard. When I corrected the situation to agree with the gauge, the dummy chambered fine.

The gauge agrees to a standard, the gauged rounds chamber, and the factory rounds agree with the gauge.

For me, that's close enough; I'm not building ICBM's here.

Good question.

Greg
 

Yondering

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I like to have the checking taking place out in the open where I can see what's going on.

But mainly, when the symptoms appeared, the case gauge agreed there was something wrong. I kicked myself for assuming something I should have been checking against a known standard. When I corrected the situation to agree with the gauge, the dummy chambered fine.

The gauge agrees to a standard, the gauged rounds chamber, and the factory rounds agree with the gauge.

For me, that's close enough; I'm not building ICBM's here.

Good question.

Greg
When you compare your sized brass to your fired brass by measuring base to shoulder, that is out in the open so you can see it. Adjust your sizing die to bump the shoulder back .002-.004" from your fired brass.

The "known standard" should be your barrel if you want to get the most out of it. Case gauges are made to minimum spec and do not reflect what your barrel necessarily needs. This has been discussed here a lot.
 

AZgeek

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When you compare your sized brass to your fired brass by measuring base to shoulder, that is out in the open so you can see it. Adjust your sizing die to bump the shoulder back .002-.004" from your fired brass.

The "known standard" should be your barrel if you want to get the most out of it. Case gauges are made to minimum spec and do not reflect what your barrel necessarily needs. This has been discussed here a lot.
Absolutely correct. I'll go as far in saying they are worthless.
 

hlee

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Worthless is a stretch, but like all tools, you gotta understand your use case.

I had a very difficult to load cartridge pop up in my handloads at a match. Bear in mind that I intentionally crush cases back to factory fresh dimensions- full length resize with cam over. Having a sticky case, upon chambering, was unexpected. Running all of my "FL resized" cases through my rifle yielded ~ 10% that were oversized, compared to my chamber. A case gauge gave me a slightly higher % of "failures." Running those empty cases through the gun was a pain in the dick. But, using a case gauge is...
IMG_3059.JPG
I've since found that particular die is out of spec (based upon comparing results using that case gauge), and replacing it with a different die solved my sticky case issue. The gauge made comparing results from dies easy, and I've also found that if the case doesn't fit the gauge, it probably won't fit my chamber. My primary concern is reliability and I'll gladly take a hit on case life, to prevent a stuck case.

Saying a case gauge is totally worthless is like throwing out your hammers because they suck at turning screws...
 

AZgeek

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I just use the rifle in question as my case gauge as part of setting up my FL sizing operation. For me, a case gauge is worthless. They sit up on the shelf and collect dust.
 

Yondering

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Worthless is a stretch, but like all tools, you gotta understand your use case.

I had a very difficult to load cartridge pop up in my handloads at a match. Bear in mind that I intentionally crush cases back to factory fresh dimensions- full length resize with cam over. Having a sticky case, upon chambering, was unexpected. Running all of my "FL resized" cases through my rifle yielded ~ 10% that were oversized, compared to my chamber. A case gauge gave me a slightly higher % of "failures." Running those empty cases through the gun was a pain in the dick. But, using a case gauge is...
View attachment 7202764
I've since found that particular die is out of spec (based upon comparing results using that case gauge), and replacing it with a different die solved my sticky case issue. The gauge made comparing results from dies easy, and I've also found that if the case doesn't fit the gauge, it probably won't fit my chamber. My primary concern is reliability and I'll gladly take a hit on case life, to prevent a stuck case.

Saying a case gauge is totally worthless is like throwing out your hammers because they suck at turning screws...
I'm not saying case gauges are totally worthless (although I have very little use for them, including for my competition ammo), but there are better ways. I am not suggesting to check every cartridge in your AR barrel, that would suck. It works well for Glocks, but not for most rifles.

Have you learned how to measure shoulder bump? It's as easy as checking with a gauge, and it tells you exactly where you're sizing to relative to the fired brass from your chamber.

This is my own shop-made headspace tool (the steel piece on the left caliper jaw in the pics) but you can buy the Hornady tool pretty cheap. It's hard to see in this pic, but they are basically a precise sized hole that contacts the midpoint of a case shoulder.
Zero on fired brass from your rifle's chamber. For best results, deprime first (but don't size). You should check on a few pieces of brass, but don't need to check all of them, just confirm a good zero point.


Then do the same measurement on your fired brass. You can check all of them quickly this way, just leave the caliper zeroed from step 1 above. You'll usually want to see .001-.002" bump for bolt guns, and .002-.004" bump for ARs and other semi autos, assuming you are FL sizing.


This requires correct die adjustment rather than just running it down to the shellholder. Once you start measuring this way, you may be surprised to learn how far off a traditional die adjustment can be. You can easily see .005-.006" difference in changing the amount of cam-over, for example. With most sizing dies and factory barrels though, setting your die at the shell holder with some cam-over can result in .010" or more shoulder bump, which is too much, and I've seen over .020". That is what fitting to a case gauge can get you as well if your barrel is not cut to minimum specs.

The difference between measuring like this and using a case gauge is that when measuring, you actually know what you're doing to the brass.

Hope that helps.
 
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Yondering

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Also, if you don't have a tool yet, you can use a piece of sized (so it's round) pistol brass, choose something that approximately fits the midpoint of the shoulder on the cartridges your sizing. Shown here with a piece of .357 Mag brass. This is slower and more awkward (so definitely buy a tool) but will get you by in a pinch.

This measurement shows I've bumped the shoulder back .003" on this piece of 6.5 Creedmoor brass, perfect for an AR.
 

Yondering

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Running all of my "FL resized" cases through my rifle yielded ~ 10% that were oversized, compared to my chamber.
A different point to make here - if you're seeing enough variation in your sized cases to cause problems, it's probably time to anneal your brass.

As the brass gets work hardened from repeated firing and sizing, it becomes more "springy" and resists sizing. At some point you'll have to either change the sizing die setting or anneal the brass back to your starting point again, because the initially correct die adjustment won't size enough to counter the brass spring back.

This will show up in measurements like I pictured above, and you'll detect it earlier than using a case gauge, before it becomes a problem.
 

hlee

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I've read about the wonderful world of "bump sizing" for quite a while, but my process isn't "broke," so I was uninterested in fixing it. That said... I was at Cabelas today and picked up a head space comparator- because I need another step in my reloading process. I've got a new 224 predator barrel and a bunch of virgin brass, so it should be an interesting process anyway. Measured to the datum line on a representative sample of brass and will do some loading this week.
 

Greg Langelius *

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I've been doing initial load development with my 24" 6.5 Grendel, and notice that some load data sources list very conservative powder charges, and others go rather quite a bit further.

I also noticed that there are two chamber/barrel extension/bolt configurations that represent a design evolution, and that the latter version (Gen 2/MK136) exists because of bolt failures

It makes excellent sense to me that there is some reservation about publishing stout data because the publisher cannot control which bolt design is being used and cares to err on the side of caution.

I was just wondering if there might be less need for an excess of caution with the Gen 2 bolts, or whether there might be another reason for the apparent excess of caution.

Greg
 
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