6.5cm AR10 ammo recommendation for lighter loads. NOT a cycling problem

rockwind1

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I've already had a couple decent recommendations,,, is there any consensus out there? 16" barrel. getting pressure marks on current choice. I really don't want to started reloading for this gun, it's not a daily shooter. just some decent ammo but not factory "hot"
 
Did you ever get the Adj. GB adjusted to a more constricted flow ? Especially with your suppressors ?

Other wise I can't say I have seen many lower pressure 6.5CM loads.

On the flip side... Fed. 120gr OTM AE has popped primers in my otherwise GTG 6.5CM's

Hopefully others have some better input, ammo wise.
 
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I am shooting 260, pretty close.

I'm running 130s and 136s at various speeds. H4350 or RL16.

Or any loaded factory stuff in the same grain weight. Hornady eldm 130, etc.
 
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Knowing more about your setup will help. Not all 6.5creed gas guns are created equal. 2 of 8 I have only runs the same with the same factory ammo (Hornady 123sst/amax).
 

Currently out of stock, but probably not for long. It's a lighter load based on what I've gotten from my 22" Proof. Shoots great groups for me.

You can email him too and ask about his other stuff.
 
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I've already had a couple decent recommendations,,, is there any consensus out there? 16" barrel. getting pressure marks on current choice. I really don't want to started reloading for this gun, it's not a daily shooter. just some decent ammo but not factory "hot"
What do your pressure marks look like?

Could it be your chamber is cut a c hair on the large side and is leaving ejector marks/swipes due to your brass having to expand to the chamber size?
 
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What do your pressure marks look like?

Could it be your chamber is cut a c hair on the large side and is leaving ejector marks/swipes due to your brass having to expand to the chamber size?
well, defintely ejector mark, medium heavy. also a mark from inside the bolt where it has cut out. flat primers, no cratering though. and some extractor marks. how does someone see if chamber is on the large side? actually, i think i know. will go measure.
 
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Did you ever get the Adj. GB adjusted to a more constricted flow ? Especially with your suppressors ?

Other wise I can't say I have seen many lower pressure 6.5CM loads.

On the flip side... Fed. 120gr OTM AE has popped primers in my otherwise GTG 6.5CM's

Hopefully others have some better input, ammo wise.
gas block is adjusted well. i did just try out a different ammo yesterday and it is working really good. hardly any signs of pressure
 

Currently out of stock, but probably not for long. It's a lighter load based on what I've gotten from my 22" Proof. Shoots great groups for me.

You can email him too and ask about his other stuff.
interesting stuff. i did find some hornady that is working good. but i will check out that
 
My LMT MWS 6.5CM 20" SS match barrel absolutely loves the Federal gold factory loaded with 130g berger hybrid OTM--like, crazy loves...1/3 MOA-no seriously shoots better than me. 120g or 140g match by others, including berger bullets...not so much. Of course my MPA/Curtis action bolt gun absolutely loves 140g ELD match, and doesnt like the lighter stuff. Its a tough life having to buy off-the-shelf.
 
My LMT MWS 6.5CM 20" SS match barrel absolutely loves the Federal gold factory loaded with 130g berger hybrid OTM--like, crazy loves...1/3 MOA-no seriously shoots better than me. 120g or 140g match by others, including berger bullets...not so much. Of course my MPA/Curtis action bolt gun absolutely loves 140g ELD match, and doesnt like the lighter stuff. Its a tough life having to buy off-the-shelf.
bummer, i had almost a whole case of that ammo, which is what i had laying around when i started using in this gun 2 years ago, and i never noticed the pressure signs with those 15 ish shots,,, so as i was putting this thing back into action, i ordered ANOTHER CASE of the fgmm 130 gr berger ammo, thinking it would work fine, then the blown primer kind of tipped me off, and now i am never going to use it probably. so now i have 1 brand new case of 200 unopened, and probably 8 boxes. now i am trying to find a decent price on the hornady that is working,, the shipping is ridiculous these days .

i wonder why the federal is too hot for my gun? i have a jp high pressure bolt "matched" to the criterion barrel. (whatever "matched" means) . i mean, LMT makes great stuff. i have a lmt bcg in my "precision" 223 i built a few years ago. works great. well, one day, i will figure out why my gun can't handle the 130 gr fed.
 
Can you post a picture of your fired brass
yes, i am sorry for the delay. the one on the left has same type of marks, the sun is just hitting it differently
 

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bummer, i had almost a whole case of that ammo, which is what i had laying around when i started using in this gun 2 years ago, and i never noticed the pressure signs with those 15 ish shots,,, so as i was putting this thing back into action, i ordered ANOTHER CASE of the fgmm 130 gr berger ammo, thinking it would work fine, then the blown primer kind of tipped me off, and now i am never going to use it probably. so now i have 1 brand new case of 200 unopened, and probably 8 boxes. now i am trying to find a decent price on the hornady that is working,, the shipping is ridiculous these days .

i wonder why the federal is too hot for my gun? i have a jp high pressure bolt "matched" to the criterion barrel. (whatever "matched" means) . i mean, LMT makes great stuff. i have a lmt bcg in my "precision" 223 i built a few years ago. works great. well, one day, i will figure out why my gun can't handle the 130 gr fed.
bummer, i had almost a whole case of that ammo, which is what i had laying around when i started using in this gun 2 years ago, and i never noticed the pressure signs with those 15 ish shots,,, so as i was putting this thing back into action, i ordered ANOTHER CASE of the fgmm 130 gr berger ammo, thinking it would work fine, then the blown primer kind of tipped me off, and now i am never going to use it probably. so now i have 1 brand new case of 200 unopened, and probably 8 boxes. now i am trying to find a decent price on the hornady that is working,, the shipping is ridiculous these days .

i wonder why the federal is too hot for my gun? i have a jp high pressure bolt "matched" to the criterion barrel. (whatever "matched" means) . i mean, LMT makes great stuff. i have a lmt bcg in my "precision" 223 i built a few years ago. works great. well, one day, i will figure out why my gun can't handle the 130 gr fed.
This may be grasping at straws, but have you scoped your barrel to see if you have any big carbon buildup, like the ‘dreaded carbon ring?’ Admittedly, had one on my bolt gun that caused my velocities to really spike (which is what caused me to look in my barrel in the first place). And yes, I cleaned regularly…apparently the “don’t use a brass brush” was not good advice for me. Anyhow, just trying to think of something.
 
This may be grasping at straws, but have you scoped your barrel to see if you have any big carbon buildup, like the ‘dreaded carbon ring?’ Admittedly, had one on my bolt gun that caused my velocities to really spike (which is what caused me to look in my barrel in the first place). And yes, I cleaned regularly…apparently the “don’t use a brass brush” was not good advice for me. Anyhow, just trying to think of something.

well,, i did shine a light down it and it looked good, peeking in from the upper, using good flashlight. I actually reloaded for years, and chased the mythical carbon ring a few times, but being wiser now, ( i think), so i took a step back and said hmmmm. i can't believe a carbon ring would appear after 40 rds. (fully admit i could totally be wrong) so i cleaned it and tried this new ammo and am pretty happy now.

sometimes i think the carbon ring is the "Bigfoot" of the reloading world. kinda mysterious, no real consensus on it, blurry pics (if any), "this guy i know had a carbon ring" etc. would love to see some definitive pics of a carbon ring vs just dirty.

although it is a mystery i would like to solve more, the fed ammo worked fine in my bolt gun (as far as pressure, not impressed by it's overall ES and SD at the time but i figure it would work fine in this AR)

also, i seem to have misplaced my lyman borescope, my garage is,,,a bit unorganized. i retired 12 years ago and my first goal was to organize my garage, 12 years later,,,,,it is still my goal.

but in the meantime, it's shooting acceptable! going to go look for my borescope!

also, big shout out to frank at bartlein barrels a couple years ago. went above and beyond on my 6.5saum barrel issue. excellent customer service, amazing really.
 

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well,, i did shine a light down it and it looked good, peeking in from the upper, using good flashlight. I actually reloaded for years, and chased the mythical carbon ring a few times, but being wiser now, ( i think), so i took a step back and said hmmmm. i can't believe a carbon ring would appear after 40 rds. (fully admit i could totally be wrong) so i cleaned it and tried this new ammo and am pretty happy now.

sometimes i think the carbon ring is the "Bigfoot" of the reloading world. kinda mysterious, no real consensus on it, blurry pics (if any), "this guy i know had a carbon ring" etc. would love to see some definitive pics of a carbon ring vs just dirty.

although it is a mystery i would like to solve more, the fed ammo worked fine in my bolt gun (as far as pressure, not impressed by it's overall ES and SD at the time but i figure it would work fine in this AR)

also, i seem to have misplaced my lyman borescope, my garage is,,,a bit unorganized. i retired 12 years ago and my first goal was to organize my garage, 12 years later,,,,,it is still my goal.

but in the meantime, it's shooting acceptable! going to go look for my borescope!

also, big shout out to frank at bartlein barrels a couple years ago. went above and beyond on my 6.5saum barrel issue. excellent customer service, amazing really.
I have never seen a "carbon ring" in any of my guns, so no help there. What I can tell you is the 6.5creed in AR's are a plethora of problems? GAS, gas, gas is the problem on port sizing! Correct size per location is KEY! A 22" aero precision barrel uses standard rifle length gas with standard weight spring and buffer without issues. For the rest of the brands even with + systems will need extra attention. I know because I have several with and without +2 that pop primers until buffer spring and buffer are adjusted/tuned for them.

my list of makers I've used with issues with +2 and not.
faxon
proof
cbi
bsf
too start with
 
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well,, i did shine a light down it and it looked good, peeking in from the upper, using good flashlight. I actually reloaded for years, and chased the mythical carbon ring a few times, but being wiser now, ( i think), so i took a step back and said hmmmm. i can't believe a carbon ring would appear after 40 rds. (fully admit i could totally be wrong) so i cleaned it and tried this new ammo and am pretty happy now.

sometimes i think the carbon ring is the "Bigfoot" of the reloading world. kinda mysterious, no real consensus on it, blurry pics (if any), "this guy i know had a carbon ring" etc. would love to see some definitive pics of a carbon ring vs just dirty.

although it is a mystery i would like to solve more, the fed ammo worked fine in my bolt gun (as far as pressure, not impressed by it's overall ES and SD at the time but i figure it would work fine in this AR)

also, i seem to have misplaced my lyman borescope, my garage is,,,a bit unorganized. i retired 12 years ago and my first goal was to organize my garage, 12 years later,,,,,it is still my goal.

but in the meantime, it's shooting acceptable! going to go look for my borescope!

also, big shout out to frank at bartlein barrels a couple years ago. went above and beyond on my 6.5saum barrel issue. excellent customer service, amazing really.
yeah, I missed the "40 rds" thing. Probably not a gunked up barrel.

There are MANY mythical beasts in the gun world! however, I did see spiking velocities, widening SD's (Lab Radar) and worsening accuracy (if mine could actually get worse :ROFLMAO: ). I root-caused as best I could, I buy off-the-shelf match (did anybody notice Federal gold 6.5CM 140g recently upped their velocity?) so that was easy. Finally, I bot a scope, looked down the barrel and there it was...the ring of doom (not to be confused with post-Thai food ring of fire). Of course, there was also what looks like volcanic glass starting to build up in the upper 1/3...:rolleyes: Yes, I cleaned regularly with nylon brushes and all the other popular accoutrements (other than a brass brush). Anyhow, its now all gone, barrels shinny, and I'm back to my just mildly crappy shooting with a gun and factory match ammo that shoots a hellofalot better than I do. Do note, that buildup took just over 500 rounds to get there...so there's that.
 
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I have never seen a "carbon ring" in any of my guns, so no help there. What I can tell you is the 6.5creed in AR's are a plethora of problems? GAS, gas, gas is the problem on port sizing! Correct size per location is KEY! A 22" aero precision barrel uses standard rifle length gas with standard weight spring and buffer without issues. For the rest of the brands even with + systems will need extra attention. I know because I have several with and without +2 that pop primers until buffer spring and buffer are adjusted/tuned for them.

my list of makers I've used with issues with +2 and not.
faxon
proof
cbi
bsf
too start with
I think got lucky with the LMT and its 6.5CM SS 20" barrel set up. I think you are right on the gas part regardless. What I do get is the brass blasted out and dented on ejection. Had to put a piece of foam on the side. It doesnt do that to the brass when I have the 16" CM .308 barrel on.
 
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What weight bullets are you shooting?

You already saw the ejector impression, that takes a tremendous amount of force to imprint like that.

If you are shooting 140s, that's likely the issue. A lot of the 140s have a longer bearing surface as well.

Your brass does look like the carbon covered the entire side, but I can not tell. That's a sign your rifle is ripping the case out of the chamber prematurely in relation to when its meant to do so. You'll notice that that brass will also be harder to size(unless it's super high quality brass it might not). Sometimes people think that's from a horrible and oversized chamber but it's not.
 
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What weight bullets are you shooting?

You already saw the ejector impression, that takes a tremendous amount of force to imprint like that.

If you are shooting 140s, that's likely the issue. A lot of the 140s have a longer bearing surface as well.

Your brass does look like the carbon covered the entire side, but I can not tell. That's a sign your rifle is ripping the case out of the chamber prematurely in relation to when its meant to do so. You'll notice that that brass will also be harder to size(unless it's super high quality brass it might not). Sometimes people think that's from a horrible and oversized chamber but it's not.
i'm sorry, i thought i put that in the post. i was shooting the federal gold medal match 6.5cm with the 130gr berger hybrid otm. so you think the bolt is moving backward before the gas has time to do it's thing? do you think adding another tungsten weight to the buffer would help?
 
i'm sorry, i thought i put that in the post. i was shooting the federal gold medal match 6.5cm with the 130gr berger hybrid otm. so you think the bolt is moving backward before the gas has time to do it's thing? do you think adding another tungsten weight to the buffer would help?

I missed it but you did have that info there, I'm running no sleep.


I need to see the side view on the brass to make a guess, that will tell us more. The two pics I posted above are showing what I'd look for. I tried to find pics of brass from guns that were violently timed wrong, but I can't find any.

But, 130s should typically be fine, did you capture any muzzle velocity? There is a chance it could have been a hot lot#?

You could try more buffer weight...try to post more pics of the brass in good light though. Line up 10 pieces or so if you can.

So hornady is working well?

This is a factory LMT?
 
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Side view too, and into the rims if you can get it

Like these

That’s coming out of your A.R. 10? Wow, your brass is nice and clean compared to mine even the new stuff Hornady that shooting well out of a 10 round magazine in the bottom eight are pretty filthy, anyways here’s some pics of the federal stuff that I stopped shooting.i did roll Them around for a couple different angles of the sides. It’s not all just one side.
 

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i'm sorry, i thought i put that in the post. i was shooting the federal gold medal match 6.5cm with the 130gr berger hybrid otm. so you think the bolt is moving backward before the gas has time to do it's thing? do you think adding another tungsten weight to the buffer would help?
Isn't it short stroking or not ejecting? Another heavier weight isn't going to help. If the gb is working as it should, then the gas port is still the issue. If you have a lighter bcg I'd try that 1st before going heavier in the buffer. All bolts will have "push back" (not technically, but pushed back against the extension) against the when fired, but a bcg will not unlock until the gas hits the key. Brass should expand to "seal" the gas (neck area) as what it's designed for).
 
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Isn't it short stroking or not ejecting? Another heavier weight isn't going to help. If the gb is working as it should, then the gas port is still the issue. If you have a lighter bcg I'd try that 1st before going heavier in the buffer. All bolts will have "push back" (not technically, but pushed back against the extension) against the when fired, but a bcg will not unlock until the gas hits the key. Brass should expand to "seal" the gas (neck area) as what it's designed for).
oh no,, it is cycling fine, piece of cake. i was having overpressure problems until i switched to hornady 95 gr ammo. now i was just wondering why i had over pressure, and was looking into reducing blowback since it is a pretty short barrel, 16", suppressed
 
i'm sorry, i thought i put that in the post. i was shooting the federal gold medal match 6.5cm with the 130gr berger hybrid otm. so you think the bolt is moving backward before the gas has time to do it's thing? do you think adding another tungsten weight to the buffer would help?
@rockwind1
Your bolt is unlocking too early. The extractor trying to rip the rim off is a good sign as well as the false pressure signs on your brass. Which buffer weight are you using? Whatever it is, it needs to be heavier. Possibly a stiffer spring as well. An adj gasblock does help but as you can see from your rifle, it isn’t a fix.
 
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oh no,, it is cycling fine, piece of cake. i was having overpressure problems until i switched to hornady 95 gr ammo. now i was just wondering why i had over pressure, and was looking into reducing blowback since it is a pretty short barrel, 16", suppressed
Between 3 threads of near same issues, I get lost on which 1 is which? Ok, I've re-read your post above and you're stated a cbi barrel. I have a 20" standard rifle gas system and it blows primers bad w/Hornady 123 amax and sst's. Accuracy is exceptional (2 shots in near same hole). Thought I missed, so I went and checked the target and the hole was barely oval. Which gas length is it? I'm sure it's short (maybe mid length, hopefully not carbine length). H3 should cover the issue. Being that short it might take H4?
 
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oh no,, it is cycling fine, piece of cake. i was having overpressure problems until i switched to hornady 95 gr ammo. now i was just wondering why i had over pressure, and was looking into reducing blowback since it is a pretty short barrel, 16", suppressed


Holy cow, 95 grain? You should have to go that light....
 
I'm awaiting on an A1 buffer tube to test on 243win, 260rem and 6.5creed in carbine stocks. What this will let me do (if I've done the math) will let me use an AR15 carbine buffer (3 weights instead of 2 like AR10 carbine buffers) with AR10 rifle spring (or flatwire).
 
So I am kinda thinking the same as above. And after seeing your brass it's way dirty, you are definitely over gassed.

You need to reduce gas, probably by an adjustable gas block first.

Once you do that look at:

1. Spring
2. Buffer weight

The tendency is to go heavier spring, which is not usually right for full mass bcgs.
 
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I'm awaiting on an A1 buffer tube to test on 243win, 260rem and 6.5creed in carbine stocks. What this will let me do (if I've done the math) will let me use an AR15 carbine buffer (3 weights instead of 2 like AR10 carbine buffers) with AR10 rifle spring (or flatwire).

You'll need a spacer I believe.

The best combo I have found is the 308 rifle spring in a 7 5/8" internal receiver extension, with what ever 3 1/4" weight buffer you tune to.

I shoot both suppressed and not, and my rifle functions well with the ability to adjust gas for each set up.
 
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So I am kinda thinking the same as above.

You need to reduce gas, probably by an adjustable gas block first.

Once you do that look at:

1. Spring
2. Buffer weight

The tendency is to go heavier, which is not usually right for full mass bcgs.
He stated he has an abg. Still having issues before ejection.
 
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You'll need a spacer I believe.

The best combo I have found is the 308 rifle spring in a 7 5/8" internal receiver extension, with what ever 3 1/4" weight buffer you tune to.

I shoot both suppressed and not, and my rifle functions well with the ability to adjust gas for each set up.
I meant A5 tube instead. Between "A" and "B" 5's I forget 1 is furniture and the other is recoil systems? Not usually my realm?
 
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Okay these are three pieces of alpha brass I just shot the other day, what I consider almost a perfect hand load. I'll add the velocity data as well. At about 2800 mv for a 130 AR Hybrid.

17015684691584107823204424309009.jpg


17015684973256795045031767703953.jpg


Screenshot_20231124_155846_ShotView.jpg
 
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I'm awaiting on an A1 buffer tube to test on 243win, 260rem and 6.5creed in carbine stocks. What this will let me do (if I've done the math) will let me use an AR15 carbine buffer (3 weights instead of 2 like AR10 carbine buffers) with AR10 rifle spring (or flatwire).
No. That is a rifle receiver extension. You will need a ar10 rifle buffer and spring. You need a vltor A5/armalite receiver extension or similar to do what you are stating. These are 3/4” longer than a standard regular ole carbine receiver extension.
 
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I missed it but you did have that info there, I'm running no sleep.


I need to see the side view on the brass to make a guess, that will tell us more. The two pics I posted above are showing what I'd look for. I tried to find pics of brass from guns that were violently timed wrong, but I can't find any.

But, 130s should typically be fine, did you capture any muzzle velocity? There is a chance it could have been a hot lot#?

You could try more buffer weight...try to post more pics of the brass in good light though. Line up 10 pieces or so if you can.

So hornady is working well?

This is a factory LMT?
no, it is not as high dollar as a LMT, but it is well built with some nice components. criterion 16" barrel, jp HP bolt, jp silent capture spring, midland rail, odin AGB, nice trigger, PSA upper/lower, running a tbac ultra 7 30 call

hornady 95gr amax's working well at 3020 fps

the fed fggm 130 bergers was shooting 2650 i do not know if that is hot in a 16" barrel

i posted some more pics if you want to see them.
 
So I am kinda thinking the same as above. And after seeing your brass it's way dirty, you are definitely over gassed.

You need to reduce gas, probably by an adjustable gas block first.

Once you do that look at:

1. Spring
2. Buffer weight

The tendency is to go heavier spring, which is not usually right for full mass bcgs.
i already have an odenworks agb set just about right, basically it is just above bolt lockback.

did you mean what top of texas said above?

my bcg weights 17.75 oz's. i presume it is full mass. not sure how to tell
 
I'm talking about the gas being set too high.

And then....

And depending on his spring/buffer and receiver extension there may be some other changes needed as well ^
to set the gas block, i kept increased it 1 click at a time until it locked back on empty mag.

to be fair, if i only put one clean round in the mag and shoot it, it is not as dirty as the ones down in the mag that get pummeled with gas.
 
are you saying cbi barrels have a gas port problem,, like too big? or too small?
I'm not totally sure, but even with an agb with standard weight buffer and spring it still pops primers. I bought a pin set from Penn Tool to check (within reason) port sizes.