Once fired lake city 308 brass issue

[Abram]

I purchased some once fired lake city brass and have finally gotten around to processing it. It looks to be good brass but looks can be deceiving. During the resizing process several cases did not go all the way into my case gauge and what I men is the rim of the case would not sit flsuh or right below flush. Some of them you could gently push and the case would go all the way. I checked my sizing die and all is good and not all of the cases do this. Do you guys have any ideas as to what may be causing this? All of the cases still have the primer crimps.

Thank you

 

[Nick Caprinolo]

Use a small base sizing die.

 

[old codger]

Try annealing your brass before sizing. Sometimes that helps. If it does not help then the small base sizing die.

 

[243winxb]

Burr on rim?

 

[Nick Caprinolo]

If you brass is fired from an autoloder such as an AR type rifle, the rear of the case does not go into the chamber like bolt actions do. This causes the bottom portion of the case to expand further than it would from a BA rifle. That's why you need the small base die. It forms the case further closer to the rim.

 

[Barman54]

Naw, this is what you do!!

Run your entire .308 Brass through a 30.06 Sizing Die.
Then run them through your .308 Die.
Trim, and Load, No Problem.

Speaking from an M1A Shooter

M1A, eats Brass

Thx,
Barman54
Out

 

[Ken]

Did they chamber in your bolt rifle? I assume not.

 

[762willdo]

Sounds like machine gun brass……..

 

[6BRA]

I bought a bunch of machine gun brass once...to say it is hardened would be an understatement....if you can anneal it....do it!

 

[RegionRat]

Do you guys have any ideas as to what may be causing this?

Sized but won't plunk into chamber gage...
The gage can be one of two types, the kind that only checks the shoulder datum length, or the kind that mimics a SAAMI spec (chamber) so it can hit at any place in the envelope.

First question is what type of gage are you using?

If your shoulder isn't set back enough, then you need to describe how you adjusted the shell holder to die relationship. Also, it would be a good idea to describe what sizing die you used.

If your gage is the kind that checks the whole envelope, then the three main places to look are:
1. The shoulder datum length mentioned above.
2. The "200 line" which is the diameter at a point 0.200" above the base of the case.
3. The body to shoulder junction diameter

A caliper and a 0.400 dia tool is used for number 1, but you need a micrometer for 2 and 3.

One or a combination of those is usually to blame in about four out of five instances of this type of issue. One time out of five, there is a long list of less common issues that can cause this as well, but you may as well learn to eliminate the important ones first. Things like being dented, nicks, scratches, or bent rims etc., can cause issues in abused brass.

Easy bolt closure on your rifle also counts as a gage, so don't forget to test this too.

Brass surplused from MIL or LEO use where it has been fired in machine guns is notorious for being bulged in that 200 line area and often as not a small base die would be required to get it back into spec. You may as well verify the case length is below 2.015" while you are at it.

Here is a SAAMI diagram of the ammo specification. You will see the dimensions mentioned above.
Shoulder Datum (B) max 1.634"
Body Shoulder Junction (Delta) max 0.4540"
200 line (B) max 0.4703"

 

[Webster]

I purchased some once fired lake city brass and have finally gotten around to processing it. It looks to be good brass but looks can be deceiving. During the resizing process several cases did not go all the way into my case gauge and what I men is the rim of the case would not sit flsuh or right below flush. Some of them you could gently push and the case would go all the way. I checked my sizing die and all is good and not all of the cases do this. Do you guys have any ideas as to what may be causing this? All of the cases still have the primer crimps.

Thank you

Probably fired in a semi-auto with a big chamber? Bolt action VS M14.

 

[Walt Krafft]

If it is machine gun brass it is junk and not worth fooling with. Check the over all length. If you are going to need to trim 0.040 or more don't waste your time. It is a head separation waiting to happen.

 

[jsn]

Either bulge at the base or rim damage. Could be either, or both.

 

[Park ranger]

Naw, this is what you do!!

Run your entire .308 Brass through a 30.06 Sizing Die.
Then run them through your .308 Die.
Trim, and Load, No Problem.

Speaking from an M1A Shooter

M1A, eats Brass

Thx,
Barman54
Out

I’ve never heard that before. Are you serious?

 

[Metal God]

f it is machine gun brass it is junk and not worth fooling with. Check the over all length. If you are going to need to trim 0.040 or more don't waste your time. It is a head separation waiting to happen

That could be true but not necessarily . I have access and prep large lots of LC 308 brass fired from machine guns . I always have to trim a significant amount off after the first sizing . Couple reasons for that one is those Machine gun chambers are quite generous so the brass comes out bloated and longer datum to Case head than you normally would see in a bolt gun .

This means there’s much more brass to squeeze back down to spec especially when using a small base die which you should on the first sizing . This results in more brass extruding out through the neck as the whole of the case is sized back down. To be honest I don’t really remember ever measuring the length of those cases after sizing but do you remember needing to trim quite a bit off .

Once done I can still get several loadings out of this brass and only bumping the shoulders .002 from then on . Like I said I have several thousand cases with different gearhead stamps so I don’t go through that many individual lots much . I do however have one lot that has over 10 loads on it with two Anneals after each 4th firing and they are gtg to go for there 11th . Now this is shooting from a bolt gun with minimal sizing .

Your results may differ substantially depending on the gun you’re using and your case prep method. I have an AR 10 that would eat that same brass up and spit it out within four loads . Regardless what I find is like most do, my primer pockets start to loosen up before I split necks or case head separation .

 

[Bob3700]

What is the intended use for this brass and do u know what type of gun it was fired in. If it came from a bolt gun or match chambered M1A then I would use it. If it is unknown origin, Walt is right, don't fool with it. Head separations waiting to happen.
If the brass is to be used for hunting or casual shooting, use a small base die and that should solve ur issue.

Bob

 

[Downhill]

Had a similar issue with M852 match brass. Annealing solved the issue. Lake city brass seems to be hard as a nail.

 

[Bill K]

More than likely fired in a semi-auto chamber, so you will need a small base FL sizing die to resize it so it will slide into your bolt or lever action chamber.

 

[Abram]

thanks for all of the replies.
I purchased the brass online from what I thought was a reputable dealer. I am using a standard Lee resizing die. My gauge is a standard Hornady Case Gauge. and this ammo is to be fired in my M1A Standard. I have not tried to chamber it in any of my guns yet. I have never annealed brass so there will be slight learning curve.

The brass will slide all of the way into the gauge, it's just the rim will not go down to the point where it is supposed to.

Thank you for all of the suggestions and help.

 

[Coyotefurharvester]

So if you flip the case around the rim end will not fit into the case gauge(this the quick way to check the .200 line). If it fits the gage it should work in any SAAMI chamber, the ammo/brass that fits your chamber MAY NOT fall in between the steps.