Is this pressure or something else? LC Brass .308

[Jason D Hostetter]

Sizing the base .006" is going to cause a lot of case stretching and eventually a case head separation. Find a die that only sizes about .002" under a fired case. I'd invest in some good brass, LC 308 is good for destroying in an AR10. Their 5.56 brass is stellar, 7.62 not so much. Almost sounds like you have an rcbs sb die.

 

[Straightshooter1]

Fired measures at .466. Sized in an RCBS FL die measures .460

Going from .466 to .460 is huge! And it's not good for your brass (making for a very short life).

When I size my brass I'm only moving it .001 to .0015 in my .308 Forster FL sizing die. Usually "clickers" are from brass that isn't sized enough, and I've not heard of brass sized that much resulting in clickers???

 

[fisherman987]

Fired measures at .466. Sized in an RCBS FL die measures .460

 

[243winxb]

LC LR brass is having the bolt issue. The other brass, factory FC 308 is not

Primers show high pressure.

Different case volume? May need different loads. Less powder for LC?
https://www.accurateshooter.com/cartridge-guides/308win/

The most important thing to remember about military brass is that the internal capacity will probably be less than commercial .308 Win brass, because military brass often has thicker webs or casewalls. Montana Marine reports his fire-formed milsurp cases hold 56 grains of H20 on average compared to 58 grains for fire-formed Winchester. Given the reduced capacity of military brass, you should reduce posted max loads by 1.5 grains when loading with Lake City or most other milsurp brass.

 

[Doom]

Neither 0.460 or 0.466 make sense. That is way under SAAMI for a 308 Chamber. I would expect a number closer to 0.470x.

 

[DShortt]

Neither 0.460 or 0.466 make sense. That is way under SAAMI for a 308 Chamber. I would expect a number closer to 0.470x.

Agreed.
To the OP - are you certain you are taking that measurement at the .200 line? If so, you need a different FLS die or you have a very odd chamber.
Fired brass that sticks with a .466" measurement at the .200 line in a .308 chamber? Something isn't right.

 

[Adam0321/0306]

Agreed.
To the OP - are you certain you are taking that measurement at the .200 line? If so, you need a different FLS die or you have a very odd chamber.
Fired brass that sticks with a .466" measurement at the .200 line in a .308 chamber? Something isn't right.

No, I am not certain. I will double check. Thanks for all the replies and help.

 

[Buttstock-TX]

I had a similar issue in factory Savage chamber with once fired LC 7.62 brass that was test fired at the factory in a machine gun. I was able to overcome the problem by purchasing a tight base Redding FL sizing die.

 

[243winxb]

once fired LC 7.62 brass that was test fired at the factory in a machine gun.

Mostly sold as scrap. https://www.army.mil/article/11859/ammunition_manufacturing_quality_control_crucial_to_success

The approximate shelf life of the ammunition is also tested here. "We place the ammunition in a chemical solution. This process allows for the brass imperfections to be easily identified" said Ojeda. "Any potential defects in the brass will become more apparent due to the reaction of the solution. Theoretically, the test makes it possible to identify flaws in the brass that under normal conditions, could only be noticed after a lengthy period of time."

 

[DShortt]

So if you look carefully at the attached image, about midway down on the left side you will see a distance from the case head referenced as .200B. Follow that line up and it shows a dimension (diameter in this case) of .4703.

That is why many of us are confused when you state your fired brass measures .466 and your sized brass measures .460 at the .200 line.
That doesn't seem possible.

 

[243winxb]

.4703

-008" or a minimum of .4623"

 

[DShortt]

-008" or a minimum of .4623"

It is maximum cartridge, minimum chamber.

 

[DShortt]

 

[DShortt]

I can tell you my sized .308 brass measures .465 and fired brass .467 at the .200 line. Two different chambers.
.460 seems....... unlikely.
Doesn't seem likely that fired brass that measures .466 would be hard to extract, either.

 

[Adam0321/0306]

Ok, so I just grabbed six pieces of brass from yesterday’s match. Three that were “clickers” and three that are not. I checked the spent cases in my rifle, and the three clickers do produce the issue.

These are measurements from the non clickers prior to sizing. The sizing die is an RCBS Full length .308 with a “Z” on it.

COAL
1.999-1.999-1.999
Guess I over trimmed
.200 line
.466-.466-.465

After sizing
COAL
2.007-2.006-2.005
.200 datum line
.463-.463-.464

these are the clickers
COAL
2.005-2.008-2.008
.200 line
.462-.462-.462
Then I sized them and they no longer “clicked”. The empty cases ejected and chamber fine
COAL
2.012-2.014-2.010
.200 line
.463-.464-.464

 

[DShortt]

Just read the first post again.

Hart barrel. Factory action?

Might be Remington and their failures with timing yet again.

 

[DShortt]

Interesting.

Any idea what reamer was used?

 

[Adam0321/0306]

Interesting.

Any idea what reamer was used?

No idea. The hart barrel and Remington action were assembled for my by the USMC PWS school in Quantico.

 

[DShortt]

No idea. The hart barrel and Remington action were assembled for my by the USMC PWS school in Quantico.

I see.

Have you fired this rifle much in the past?

Also, something doesn't add up because your 'clickers' have smaller dimensions at the .200 line than the one's that extract fine.
Same with the OAL.

 

[Florida Wally]

I had a similar problem with brass that was shot in a different rifle. The problem wasn’t the typical clicker expansion at the base, it was expansion at the body shoulder junction. I used a small base sizing die and put a noticible “shiny” ring at the shoulder body junction which showed that that area was significantly sized. I think that the other rifle chamber was larger in that area causing the case to get stuck. After sizing with the small base die, I have shot that brass several times without issue.