Lake city 308 brass load help

[Exodus343]

So I'm trying to develop a load for my M1A

I'm pushing a 147 ball with 44 grains of IMR 4064 and the result was signs of case head separation

I'm seating the round to 2.800" with a trim length of 2.005"

How much powder should I back off?
My book and the hodgdon website have stated for me to start at 43 with the max being at 46+

[highpower790]

So I'm trying to develop a load for my M1A

I'm pushing a 147 ball with 44 grains of IMR 4064 and the result was signs of case head separation

I'm seating the round to 2.800" with a trim length of 2.005"

How much powder should I back off?
My book and the hodgdon website have stated for me to start at 43 with the max being at 46+

How many times has the brass been reloaded?The load given is fine.

[Exodus343]

Once fired
So after this it's twice fired

[highpower790]

Once fired
So after this it's twice fired

And how was it loaded the 1st time?

[Exodus343]

No idea
I'm guessing it's machine gun brass?
I got the brass once fired but it was prepped and guy decided to let it go

[highpower790]

No idea
I'm guessing it's machine gun brass?
I got the brass once fired but it was prepped and guy decided to let it go

If machine gun brass that could be a problem.
How are yous sizing the brass and what if any info can you provide about the chamber.

[Exodus343]

I didn't size the brass so I can't tell about that
And my chamber is a m1a standard
Barrel, nothing fancy

[highpower790]

I didn't size the brass so I can't tell about that
And my chamber is a m1a standard
Barrel, nothing fancy

It may be that the previous user sized the brass using a small base die.In a standard M1A chamber and the possibility of machine gun brass ,the brass has been overworked.
ONe thing that can be done,and its cheap,is to open a paper clip.At one end make a short 90degree bend sharpened to a point.Use this to pick at the case head from the inside.If the point catches ,throw brass away.

[Exodus343]

I'm starting to see stretch marks on the brass even before firing
Maybe that is the case? Brass was over worked in a small base did
Or improper sizing?

[Exodus343]

The brass to the left is the "processed" brass
The brass to the right is the one I just fired

[kblack583]

I started to get case head separation on a batch of reloads for my M1A. Used comparator to check against factory loaded 7.62 and found I was pushing shoulder back farther than factory. Zero issues since then.

[highpower790]

The brass to the left is the "processed" brass
The brass to the right is the one I just fired

When was the last time the rifle's chamber was cleaned.I ask because I see the rim about to be torn away.
A case head separation will occur about .250-.400 above case rim.

[Exodus343]

I haven't cleaned my chamber yet
I'm the second owner of the rifle and I only shot 25 rounds before noticing the brass seemed kinda funny so I stopped

[maxx03]

Are you using the same sizing die for multiple 308 rifles?
If so, the shoulder is probably being set back too far.

[McGuiver]

Lake city 308 brass load help

How is the gas block setup on that. It looks like a violent extraction. Looks like it could be over gassed. Did the previous owner drill out the gas block hole?

Did it extract violently or hard? Can you get a picture of the case heads of those 2 rounds above?


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