308 sizing help using bulk machine gun brass

[P1ZombieKiller]

The last year or so I have a buddy that bought a few AR10's, and then bought bulk machine gun brass to reload.
I ran the brass through my normal 308 sizing die, trimmed it to length (to 2.005), and it is still does not chamber in his rifles.
Factory rounds do. I measured the base of the cases that I had resized, and they all measure .468 (same as my new factory Lapua brass).

If you have had experience with before, can you point me in the right direction?

Will a small base die size the bottom of the case a few thousands more? I have never used one before, so not sure what to expect.

I am loading 168grn amax to OAL of 2.800

 

[old_heli_logger]

Smoke a piece of brass with a Bic lighter and try to chamber it. Now look at the brass for any disturbance of the soot. That should tell you where your interference is located.
Good luck!

 

[Dusty Stevens]

Yes a small base die will fix em. Rcbs makes a fl sb die that i use for them. Works like a champ

 

[dttheliman]

.... this is a royal pain in the ass - I set up several sizing dies on my progressive press , going further down the case every stroke with a small base die set correctly as the last one - grease the hell out of the brass and exercise my arms until it’s done several hundred at a time - works for me

Edited to add this is once fired LC brass bought in bulk

 

[K22]

In my humble / non expert opinion, you are asking for trouble trying to reuse these cases. I personally wouldn't use them.

However, if you insist in proceeding, a small base die may solve the problem but be diligent in inspecting cases after each firing for potential head separation.

Once the cases are fired formed after using the small base die you may be able to resume using a standard full sizing die.

 

[Liven The Dream]

You maybe wasting your Time and Money ?
If I was tiring to fit a size 7 foot in a 6 Narrow Shoe I would try !
First a Body Die ,then as stated above a Small Base Die.

I think a Old Copy of a Speer #8 Reloading Manual , is still of great Value !

 

[Bob3700]

MG brass is a waste of time n money. That brass is stretched n u will be lucky if u don’t have head separations on the first firing. That stuff was on the market years ago when competitors were still shooting M1As. It was a bad experience then and I can’t imagine MGs treat their brass any better today.
see what it is worth by the pound n cut ur losses, don’t mess up some nice guns.

 

[Pawnee Bill]

MG brass is a waste of time n money. That brass is stretched n u will be lucky if u don’t have head separations on the first firing. That stuff was on the market years ago when competitors were still shooting M1As. It was a bad experience then and I can’t imagine MGs treat their brass any better today.
see what it is worth by the pound n cut ur losses, don’t mess up some nice guns.

True statement. Tell your friend to sell the MG brass for junk and take the money and buy decent brass. MG brass for the reloader is nothing but problems.

 

[divingin]

.... this is a royal pain in the ass - I set up several sizing dies on my progressive press , going further down the case every stroke with a small base die set correctly as the last one - grease the hell out of the brass and exercise my arms until it’s done several hundred at a time - works for me

Edited to add this is once fired LC brass bought in bulk

I've had the same problem with the same (LC) brass. On mine, it chambered OK (don't remember having to use excessive force to close the bolt, but I might have), but would not extract without opening the bolt and tapping with a rod down the barrel. Running it through a SB die solved it.

Be careful trying to size the base using a standard die - you'll push the shoulder back too much and get case separation.

 

[P1ZombieKiller]

Thanks for the info. We are kinda stuck. This guy doesn't know anything about reloading and he bought this stuff a little over a year ago, so he is into it pretty deep.

We sized the brass, seated some dummy rounds, and he said the dummy rounds fit, so I started prepping all 1000 pieces of brass. I am at the load development, and now we find out that they really don't fit. I suspect he cranked a dummy round in there, and since it looked like it the charging handle bottomed out, he said we are good.

I will order a small base die, and also mark up a round with a sharpie, and see where the issue is. I just ran over to his house, grabbed the rifle, the loaded rounds, and the dummy rounds to do some more measurements.

 

[STS]

The phrase 'Throwing good money after bad' comes to mind. He'd be better off writing off the brass and considering it a learning experience.

 

[P1ZombieKiller]

The phrase 'Throwing good money after bad' comes to mind. He'd be better off writing off the brass and considering it a learning experience.

and i may do this..... but I am going to try resizing them first.

 

[Bob3700]

Thanks for the info. We are kinda stuck. This guy doesn't know anything about reloading and he bought this stuff a little over a year ago, so he is into it pretty deep.

We sized the brass, seated some dummy rounds, and he said the dummy rounds fit, so I started prepping all 1000 pieces of brass. I am at the load development, and now we find out that they really don't fit. I suspect he cranked a dummy round in there, and since it looked like it the charging handle bottomed out, he said we are good.

I will order a small base die, and also mark up a round with a sharpie, and see where the issue is. I just ran over to his house, grabbed the rifle, the loaded rounds, and the dummy rounds to do some more measurements.

I am sure that with enough extra SB sizing you can get it to chamber, that is not the real issue. The problem comes when you have that first head separation. A bolt gun is one thing to deal with this issue but an auto-loader is another. It will jam a live round into the remaining case that is stuck in the chamber. Now you are faced with the task of trying to remove a jammed live round. The bolt/carrier won't move as it is attached to the live round. The live round is jammed into the remnants of the separated case. Heck you say, just put a rod down the bbl and start pounding away till it clears the jam. Very dangerous business at best.
The is an old addage that says: "An ounce of prevention is worth a pound of cure". Concerned about the cost of 1000 pieces of junk 308 brass, figure out what the potential emergency room costs will be if the whole thing goes South and you are luck enough to survive an out-of-battery discharge !

Toss that brass and look for some IMI 308 brass. It is strong like LC and is made for the abuse an autoloader will give it. Just my .02.

 

[P1ZombieKiller]

I am sure that with enough extra SB sizing you can get it to chamber, that is not the real issue. The problem comes when you have that first head separation. A bolt gun is one thing to deal with this issue but an auto-loader is another. It will jam a live round into the remaining case that is stuck in the chamber. Now you are faced with the task of trying to remove a jammed live round. The bolt/carrier won't move as it is attached to the live round. The live round is jammed into the remnants of the separated case. Heck you say, just put a rod down the bbl and start pounding away till it clears the jam. Very dangerous business at best.
The is an old addage that says: "An ounce of prevention is worth a pound of cure". Concerned about the cost of 1000 pieces of junk 308 brass, figure out what the potential emergency room costs will be if the whole thing goes South and you are luck enough to survive it !

Toss that brass and look for some IMI 308 brass. It is strong like LC and is made for the abuse an autoloader will give it.

Anyone got a lead on 1000 pieces of brass? even once fired NON MACHINE GUN brass?
If I could find that, and calculate the costs, I may be able to swing him that way.

 

[jelenko]

I would add to think carefully about your liability in reloading for a friend.
His insurance company is not your friend.

 

[Fuj]

Depending on how much MG brass you have.....scrap brass
gets good money at the scrap yard. Sell it off and get the
good stuff.

 

[Scott haywood]

When you or he get ready to try the brass now that it fits, do like you would with fire forming. Put a very thin film of imperial die sizing wax on the case so that when if fires, it will form to fit the chamber better. Might help with some of the case separation issues other have brought up.

 

[Jdne5b]

My small base die doesn't do much smaller than .468. are you sure it's sticking at the base?

Another option is a rollsizer. I have one but don't know what it sizes the base to as I've never used the 308 kit. If you want more info on that send me a pm.

 

[RegionRat]

It may be a good time to study the specifics of reamers, dies, chambers, and brass so that you get an understanding of how brass and cartridges behave in dies and chambers of different types.

I have met lots of folks who shoot and reload their whole life who never really understand the issues.

I know it can be difficult to study the chamber prints of machine guns, but you can still study the brass you have and the SAAMI specs are public domain. Learning to inspect brass isn't very expensive or difficult.

 

[dellet]

JUST BUY A MACHINE GUN

problem solved