Brass issues with 6mm Creedmoor

[spudgun]

Ok, was shooting last night and one of the shooters was having a issue. Upon looking at his bench and brass he was blowing out primers from his brass.

At first we thought over pressure issues, but he was shooing factory ammo and was crono'd at 3,000 FPS, which is not really a hot load.

Factory ammo was made by Eagle Eye.

We made him stop shooting and I took 2 of the brass home with me to do some measurements on the case and primers.

I measured the web, shoulder, neck and OAL of his brass to one of my 6mm CM fired brass. Nothing was really out of line and when I resized one of his brass it came out good and my resized brass.

Looking closely at the brass and compairing it to my 6mm brass something didn't look right. The shoulder of his brass seemed to be streached (see side by side picture). I was not too concerned because the brass could just be fire forming to his chamber and could be resized back to spec.

The other one with the primers got me good. I went to re-prime one of his cases and the primer would not seat in the pocket. I took the primer and it would drop into the pocket and then when I turned the case over it would fall out.

Measured the primer and the primer pocket. You can see that it is .004" too large for the primers. The primer is a large rifle primer and to my knowledge they are one size.

Sorry but at this time I do not know what weight bullet or OAL of the assembled bullet he had.

Any ideas?

 

[bozo699]

Check for a heavy carbon ring in the throat.
Wayne

 

[spudgun]

Check for a heavy carbon ring in the throat.
Wayne

New rifle but that does not really mean anything. He had shot only about 20 rounds that night.

Are you thinking ogive of bullet hitting heavy carbon and causing no jump space and blowing primers?

 

[bozo699]

New rifle but that does not really mean anything. He had shot only about 20 rounds that night.

Are you thinking ogive of bullet hitting heavy carbon and causing no jump space and blowing primers?

Not with only 20 rounds through it, did you check case overall length, did the boat close easy? If the case is too long for the chamber it could be putting a crimp causing pressure. I know you measured it but without knowing the exact chamber dimensions there could be an issue there.
Wayne

 

[alby280]

Having the same issue with a savage 110 tactical with federal match ammo.Rifle was sent back to savage 4 days ago and waiting on the outcome that savage finds. Also a 6mm creedmoor.

 

[Ranger188]

Have you measured the length of a loaded round?
Or compare it to other loaded round.
Maybe bullet loaded long in a short freebore and jammed.

 

[alby280]

All that was checked and adjusted and same issues.

 

[243winxb]

was crono'd at 3,000 FPS, which is not really a hot load.

Sorry but at this time I do not know what weight bullet
Factory ammo made by Eagle Eye.

Bad ammo. Contact the manufacture. https://www.eagleeyeammo.com/6mm-creedmoor/

Or try a different brand of ammo first. Different ammo should tell you if its a gun problem.

 

[alby280]

It was the same with all ammo.

 

[rogn]

Can you check the mouth of the case to see whether there is any indication that the case mouth is impinging on the front of the (neck) chamber. With the problem following the rifle and not the ammo, plus the visual disparity, I would be inclined to believe you/he have a bad or inappropriate chamber.. A short or undesized neck section could trap the bullet and greatly increase chamber pressure at some point.
As reference- I once made a batch of 22BR cases and neglected to check case OAL. Stuck the neck in the throat enough to biscuit cut a primer.

 

[Capt. Oblivious]

Check the bore size, we had the same problem with a 6slr and the bore measured just a tad under .235

 

[varget204]

Have you checked BTO ? some RPR & Savages Have Short Leads,some Factory ammo can be Jammed .050- .150