Sorry about pressure signs?

[KIBarrister]

I finally have my 6.5cm AR running (by swapping to a PWS upper, which is **** by the way). Running the BCG, including bolt, I’m getting a bit of case swipe and cratering (see photos). Oddly enough, this is with factory Hornady 143 ELD-X - 143’s loaded with Superformance near (but not at) load limits is showing no case swipe and very little cratering. Worth swapping in my HP bolt? Those that know me know I’ve been dicking with the big bore 6.5 AR for three years and it is FINALLY RUNNING….

 

[outrider58]

Cratering is fine. I'm not seeing a lot of "flow". Flow is bad(flattening of the primer surface).
Let's wait to see what others think. I'm viewing from my cellphone.

 

[Park ranger]

Your fine. Does it shoot good? You should see my 1000 yard load for camp perry....lol

 

[KIBarrister]

Cratering can mean a rounded ejector, which is fine. I'm not seeing a lot of "flow". Flow is bad(flattening of the primer surface).
Let's wait to see what others think. I'm viewing from my cellphone.

Your fine. Does it shoot good? You should see my 1000 yard load for camp perry....lol

Thank you gentlemen! I was nervous with how bad this was throwing pressure signs when I first changed to 6.5 - and mostly so because it is tack driving, reliably awesome after so long trying to screw with a large bore AR. I almost skipped on the PWS upper I’d been searching for so long out of fear it’s be more of the same

 

[4g64loser]

Don't sweat it. You are good. Hornady brass is kinda soft. If you are really that concerned, measure the web area with a micrometer for expansion. If you are getting fat case heads, it's time to start backing down the load.

 

[johnkn]

Put some shoes on, you’ll be just fine.. .



.

 

[Magnumite]

Your fine. Does it shoot good? You should see my 1000 yard load for camp perry....lol

Gotta luv it!

 

[KIBarrister]

Put some shoes on, you’ll be just fine.. .



.

No love for the Jesus Boots?

 

[PlumberEd]

I had the similar swipes with my suppressed 6.5 CM AR10, but velocity was spot on and I didn’t have any other p signs. I concluded the AR10 is incredibly hard on brass.

 

[4g64loser]

I had the similar swipes with my suppressed 6.5 CM AR10, but velocity was spot on and I didn’t have any other p signs. I concluded the AR10 is incredibly hard on brass.

And overgassed.

 

[PlumberEd]

Yep, I had to install an adjustable gas block

 

[KIBarrister]

And overgassed.

No worry there, this is a long stroke piston variety (adjustable). I do love PWS. I did a ladder on 120cx (after this original post) and got up to a flattened primer (at .8 grains below the max).

 

[4g64loser]

No worry there, this is a long stroke piston variety (adjustable). I do love PWS. I did a ladder on 120cx (after this original post) and got up to a flattened primer (at .8 grains below the max).

PWS is the $hit. I've owned ruger, pof, and pws piston guns. Finally said F shooting gasguns with cans and DI shoots softer for going fast. If I go suppressed again, I'll do another PWS 14.5".

 

[KIBarrister]

PWS is the $hit. I've owned ruger, pof, and pws piston guns. Finally said F shooting gasguns with cans and DI shoots softer for going fast. If I go suppressed again, I'll do another PWS 14.5".

I know it is blasphemy with Chad - and I have never been a fan of short stroke AR’s - but this PWS will chew through absolutely anything (after years of never being able to get two different 6.5 cm’s to run reliably). The 14.5 I have in 223 is the same story - and never a bit of gas in the face!

 

[4g64loser]

I know it is blasphemy with Chad - and I have never been a fan of short stroke AR’s - but this PWS will chew through absolutely anything (after years of never being able to get two different 6.5 cm’s to run reliably). The 14.5 I have in 223 is the same story - and never a bit of gas in the face!

My old 9in POF was omnivorous. When we put it in a dealer sample lower, it was unstoppable. Never got into lwrc. The ruger sr556 is a budget POF, super reliable just really heavy due to thicker barrel and the classic quad rail front end.

I won't argue with Chad about a properly done DI gun. They shoot well and run "softer". Always going to beat piston in competition. That said, for off the rack reliability (especially if you don't clean your stuff) the PWS and POF stuff is a pretty high bar to compete with.

In the large frame ARs, I owned an SR25 and boy was that a huge disappointment. That thing was garbage. All that money and it was all but impossible to keep it at 1MOA with the best match ammo or handloads. If I had paid retail, I'd have been REALLY mad. Sold it, disgusted. Shot a couple of DDAs that were easily sub MOA and we'll under 2k msrp. A buddy has a 14.5 POF 308 that is at or below 1MOA with most any match grade ammo and even a couple hunting loads.

 

[Rockzilla]

Don't sweat it. You are good. Hornady brass is kinda soft. If you are really that concerned, measure the web area with a micrometer for expansion. If you are getting fat case heads, it's time to start backing down the load.

^^^ This... Hornady brass is soft, flows, try a different brand of brass, have reloaded several different types
of brass in the 6.5CM given the same data (load) Hornady brass almost always showed signs of High pressure
bolt marks, flatten primers, brass around the head area, marks etc. while none of the other brass did. So with
that me I avoid Hornady brass, 308, 6.5CM, 300WM. as mentioned if you are worried / concerned back the
load back some. but try some different brass. Just a suggestion

-Rock

 

[lazarus]

I had the similar swipes with my suppressed 6.5 CM AR10, but velocity was spot on and I didn’t have any other p signs. I concluded the AR10 is incredibly hard on brass.

Looking at those primers, it is over gassed and unlocking a bit early. That would be my guess. Dial down the gas a little and I bet that'll go away. The primer itself doesn't look bad. I see an ejector mark and extractor gouge on the case head, which also says overgassed to me.

 

[KIBarrister]

^^^ This... Hornady brass is soft, flows, try a different brand of brass, have reloaded several different types
of brass in the 6.5CM given the same data (load) Hornady brass almost always showed signs of High pressure
bolt marks, flatten primers, brass around the head area, marks etc. while none of the other brass did. So with
that me I avoid Hornady brass, 308, 6.5CM, 300WM. as mentioned if you are worried / concerned back the
load back some. but try some different brass. Just a suggestion

-Rock

I have some on order - cheers!

Looking at those primers, it is over gassed and unlocking a bit early. That would be my guess. Dial down the gas a little and I bet that'll go away. The primer itself doesn't look bad. I see an ejector mark and extractor gouge on the case head, which also says overgassed to me.

I forgot to mention, this is old brass beat up from a prior attempt at large bore AR. I have another stack of once fired from this rifle only without ejector/extractor marks; not sure why I grabbed these two. Just the same, I have the block on wide open - I run my 223 PWS on the middle setting unsuppressed and without issue. I’m going to try taking it down a peg….

 

[lazarus]

I have some on order - cheers!

I forgot to mention, this is old brass beat up from a prior attempt at large bore AR. I have another stack of once fired from this rifle only without ejector/extractor marks; not sure why I grabbed these two. Just the same, I have the block on wide open - I run my 223 PWS on the middle setting unsuppressed and without issue. I’m going to try taking it down a peg….

Different AGB for sure and different caliber, but my .308 AR-10 I had to close the gas block about 25% to prevent it from stove piping. And then I turned it down another 25% so it is half closed off and it now ejects cases on to the bench and runs 100% still.

Short action ARs, for whatever’s reason, just seem so badly over gassed.

 

[John from MD]

Don't sweat it. You are good. Hornady brass is kinda soft. If you are really that concerned, measure the web area with a micrometer for expansion. If you are getting fat case heads, it's time to start backing down the load.

Hornady brass is soft. I try not to use it if I can.