A little help

[gman47564]

does the necks and the sides of the cases have soot on them ?

 

[JohnHenry]

Friend's rifle, Remington 700 308. He wanted to work up some reduced loads using Hodgdon instructions of starting at 60% of max load and working up to max from there. Example using a 168 gr amax bullet and H4895 max load is 43.6 gr x 60%= 26.16 grains. At 30.0gr of H4895 the primers started to flatten and back out. Gas through primer pocket and scorched the bolt face. New hornady brass. What went wrong? What can be done with the bolt?
Thanks Bill
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Is it possible that a large pistol primer was mistakenly used instead of a large rifle primer. The cup thickness is appreciably different(.020 vs .027). From your photos it does not appear that the primer was significantly flattened, but that possibly a thinner cup failed.

 

[RetiredArmy]

does the necks and the sides of the cases have soot on them ?

No

 

[RetiredArmy]

Is it possible that a large pistol primer was mistakenly used instead of a large rifle primer. The cup thickness is appreciably different(.020 vs .027). From your photos it does not appear that the primer was significantly flattened, but that possibly a thinner cup failed.

Friend said they are 210m

 

[robert8904]

One thing that many do not know about light loads is that they will shorten case "headspace" which is why your friend had protruding primers. If he tested light loads more than once with the same cases this would shorten them more with each light firing. I would suggest that he measure the brass that he used for this test because full pressure loads will probably result in incipient separations. If they are very short, he may want to consider tossing them, or at least marking them.

This is correct. I have "ruined" some brass from shortening from reduced loads in 223, 243 and 308. I've had great results using Lyman lead bullet load data with AA 5744 and jacketed bullets. At about 2,000-2100 fps the pressures are around 20,000-24,000, enough to prevent shortening the cases. I'm getting good accuracy in 223 and 243. In 308, accuracy can be amazing! 5744 is fast burning for a rifle powder making for a quick enough pressure rise to keep the brass from shortening plus it's not sensitive to powder positioning.

 

[Old Navy]

Robert's post is dead on. I remember many many years ago folks having problems with H4831 reduced loads. People actually blew guns up. No one could duplicate blowing another up so people just kept shooting them. That powder is the wrong one for the job.

 

[Old Navy]

That was a good read Texas10. That refreshed my memory about the H4831 light loads. Some speculated at the time that the primer flame burned down the top of the powder charge. The data was right in from of the guy that blew his 45-70. He knew about Dacron fillers but didn't use it.

 

[Treerat-sniper]

I've used H4895 for reduced loads in several calibers for years, never had a bit of trouble.

https://www.hodgdon.com/wp-content/uploads/2016/11/h4895-reduced-rifle-loads.pdf

 

[okie]

Yes and yes!!

wow! dang it!

 

[Daddymac]

Is it just me or is that a lot of damage for a round or two, when I working something up I really examine each case after firing for signs of trouble and regroup if I find any. Did your friend continue to shoot or is that damage from one failed primer?

 

[RetiredArmy]

He continued to shoot into he discovered the problem. I'm unsure of how many rounds he shot.