A little help

[RetiredArmy]

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

 

[Bc'z]

Poor case fill with ball powder maybe.
I'd go to an extruded powder

 

[whatsupdoc]

Way too low a charge, minimum charge should be around 39 grains. Where did you get that 60% number?
Too low is sometimes worse than too high

 

[RetiredArmy]

Way too low a charge, minimum charge should be around 39 grains. Where did you get that 60% number?
Too low is sometimes worse than too high

Sorry for the sideways picture.

 

[TAJ45]

This is one off the wall question to get to my possible reason: What was the attitude of the rifle when fired? Any chance it was pointed downward, decidedly not level.
If not, either tissue or c.o.w. on top as filler may make the Hodgdon advice work better.

 

[TAJ45]

Also not enough pressure to keep base against bolt.

 

[whatsupdoc]

Well the information you followed is legitimate, never knew that you could do that with H4895.
I would call Hodgon and see what they say possibly went wrong. The bolt face looks pretty trashed bushing the bolt should solve that.

 

[whatsupdoc]

Also not enough pressure to keep base against bolt.

It could be the shoulder was pushed to far back allowing the primer to back out.

 

[RetiredArmy]

This is one off the wall question to get to my possible reason: What was the attitude of the rifle when fired? Any chance it was pointed downward, decidedly not level.
If not, either tissue or c.o.w. on top as filler may make the Hodgdon advice work better.

No sir, the rifle was level on a bald eagle rest and a rear bag. Concrete top bench. He didn't realize anything had gone wrong until he looked at the primers as he dropped them back in the ammo box after firing them. I do believe he is Don fooling with the reduced load stuff!!!
Thanks Bill

 

[Texas10]

No sir, the rifle was level on a bald eagle rest and a rear bag. Concrete top bench. He didn't realize anything had gone wrong until he looked at the primers as he dropped them back in the ammo box after firing them. I do believe he is Don fooling with the reduced load stuff!!!
Thanks Bill

Good plan! I'm including a link to an explanation of SEE, or Secondary Explosion Effect caused by too low a charge weight.

http://reloadammo.com/liteload.htm

 

[sawcarver]

How many rounds did he shoot like that? The bolt looks like a LOT of erosion for a handful of rounds. The cases dont look like they let enough gas past to do that much damage to the bolt

 

[RetiredArmy]

How many rounds did he shoot like that? The bolt looks like a LOT of erosion for a handful of rounds. The cases dont look like they let enough gas past to do that much damage to the bolt

I'm not sure.

 

[rsmithsr50]

do they say any bullet weight ? the example is a 125 I think. maybe too much bullet

 

[BoydAllen]

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.

 

[RetiredArmy]

Thank you all for the info. I have asked him to move on from this project and build her a 6br!!!!

 

[okie]

did all of that damage to bolt face occur with those few reduced loads??
It may be good to check headspace...

 

[powderbrake]

That bolt is REALLY damaged. My bolt was ruined like that because of some faulty primers. I had it repaired by GreTan https://www.gretanrifles.com/ fast and reasonably priced.

 

[billlarson]

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
View attachment 1161960 View attachment 1161961 View attachment 1161963 View attachment 1161964

Never having experienced it myself...best way I have heard of to blow up a gun is
REDUCED LOADS
I would stay away if at all possible...ESPECIALLY when loading for someone else...
Omho
Bill

 

[RetiredArmy]

did all of that damage to bolt face occur with those few reduced loads??
It may be good to check headspace...

Yes and yes!!

 

[Brians356]

I've used H4895 down around 60% of max in three different rifles - 22-250, 6mm Rem, 270 Win - and never had a hint of such trouble. But they were all with heavy-for-caliber bullets, specifically Tubb fire lapping bullets. I suspect the light bullet might have contributed to the issue, but Hodgdon do not stipulate anything about bullet weight in their instructions. Another variable is the primer used, but again I don't recall anything stipulated. Ditto bullet jump.
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