Difficult manual extraction of military cartridges

[Mongoose333777]

I built a 308 AR on an 80% DPMS pattern lower using a PSA AR10 upper, including the BCG. I also used the PSA AR10 carbine buffer, spring, and tube. I shot some commercial rounds through it to check functioning and then started using my reloaded ammo. 

From the beginning, it was difficult to manually eject a round but it has gotten much better. Now, with about 200 rounds through it, I'm still having issues if I need to manually eject a military cased round. I can eject commercial 308 cased reloads without any issues but it is impossible to eject a military cased reload. The only way to get it out of the chamber is to eject the mag and use a screwdriver to pry the bolt carrier back through the  magwell. A few LC match cased cartridges can be manually ejected but they are difficult. 

All of the brass, both commercial and military, was prepared identically and was sized twice in the same die. I am unable to find any measurable difference between the two cartridges. I figure that maybe I have a tight chamber and there is a very small difference in the case head in the military brass. Maybe as I get more rounds through it, it will loosen up enough for the issue to resolve itself. Your thoughts?

Thanks,

Ric

 

 

 

[unforgiven]

My thought brother Ric would be to run more factory ammo through the rifle.

[Frankh252]

Since a 7.62 chamber has slightly more headspace room for use in sustained dirty military environments, is it possible the used military brass has some memory of it's previously expanded dimensions that is allowing it to swell more 'perfectly' within a tight (or Match) .308Win chamber? Also, maybe dropping a few grains of powder from the reloads would help reduce case expansion? Not an expert of any grade, just pondering potentially plausible possibilities of the predicament.

[jtallen83]

Never measured it myself but if I understand correctly NATO and LC spec brass is a bit thicker, maybe this has an effect on how much it shrinks back when the pressure comes off compared to 308 factory brass. Maybe a good polishing would help the issue?

[survivalshop]

  Sounds like a Case sizing or Trimming issue . The MilSpec brass will be thicker in the web in the Base of the Case , but all else with the case should be same dimensions .

  Note also that with the thicker MilSpec Case base , it will boost chamber pressure up compared to the Commercial Brass & coupled with other factors could cause extraction issues .  You can also try a Small Base Sizer Die on the milSpec brass , maybe the case is expanding where the Full Length Sizing Die can't reach , if thats what your using .

 Has Head Space been checked ?

 Does the rifle function normally with factory Ammo  ?

  

Edited April 24, 2016 by survivalshop

[Mongoose333777]

Thanks everyone for you input. Just to reiterate, the rifle will chamber and fire factory loads, commercial case reloads and military case reloads without any issues. The problem occurs if I try to manually eject an unfired military case reload. 

All cases have been full length sized twice. Maybe I just need to use a small base sizing die, like survivalshop said. I have checked the headspace with a GO gauge and it was fine but I don't have a NO-GO or Field gauge. 

Thanks again for the input. I'll put some more rounds through it and see if it loosens up a little. If that doesn't work, I'll get a small base sizing die for the military brass. I'm really not looking forward to that after sizing 2,000 cases twice and swaging all of the primer pockets. 

[Tripledeuce]

The no-go gauge is the important one!   Without it you can't really tell if the chamber is at specs.  A chamber cast MIGHT help with determing neck length and leade.

 I'v been a smith for a long time and NEVER found small dia chambers like I have in AR[s.   Small meaning not large enough in dia.  I'v had to run a chambering reamer inot several to correct things.

 Respectfully

 Terry

[guruofhotrod]

@Mongoose333777 - Whereabouts in So Cal are you? I'm in the Santaclarita valley and work in Chatsworth and have all 3 gauges.

[Mongoose333777]

Tripledeuce,

I have a NO-GO gauge coming but I thought the reason for a NO-GO gauge was to check for excessive headspace. It appears my issue may be a tight chamber or cases requiring a touch more headspace than I currently have. I may also try polishing the chamber. Hopefully I won't need to have the chamber reamed.

Guru,

Thanks for the offer but I'm I Mission Viejo and travel south for work. 

Thanks everyone for the help.

 

[washguy]

Mongoose      run a lil flitz polish in the chamber on a 12gauge mop in a drill...might be the ticket      Wash

[survivalshop]

 Have you checked your sized cases with a case length gage ? 

 Are you Crimping the Cartridge ?

You may have a tight Chamber , but if Factory ammo is not showing the same issue , its something in your reloading process.

Cartridge over all length ( COL ) could cause issues .

 Fouled Bolt/ Chamber / Barrel Extension area , you would be surprised at what a small piece of brass can lock it up .

[mrmackc]

On 4/24/2016 at 6:29 PM, Mongoose333777 said:

Thanks everyone for you input. Just to reiterate, the rifle will chamber and fire factory loads, commercial case reloads and military case reloads without any issues. The problem occurs if I try to manually eject an unfired military case reload. 

All cases have been full length sized twice. Maybe I just need to use a small base sizing die, like survivalshop said. I have checked the headspace with a GO gauge and it was fine but I don't have a NO-GO or Field gauge. 

Thanks again for the input. I'll put some more rounds through it and see if it loosens up a little. If that doesn't work, I'll get a small base sizing die for the military brass. I'm really not looking forward to that after sizing 2,000 cases twice and swaging all of the primer pockets. 

My opinion of your problem of extracting a unfired handloaded military caused round is the thicker case round is caused by the crimped bullet being jammed into the rifling. You need to get a chamber cast made and start using a small case reloading die.

[Blak92]

Be very carefull with once fired military brass. Its mostly machine gun stuff and probably had a sloppy worn out chamber. I had a near case seperation after 1 reload of internet bought MG brass. Certainly had been fired only one time, was still crimped. Search case seperation over on m14forum.com There you can find tricks on how to spot potentially bad brass. After inspecting about 1500 of mine, I tossed about 5-600. Pretty pissed but its better than a face full of gas and metal. You can buy new LC brass under american eagle. Buy a wilson case gauge and drop all that brass in it one at a time before sizing. The ones that wont fit in around the web, or looks like its off centerline, toss em. A small base die will probably only make it worse, thinning that already stressed area even more.

 

Edited April 28, 2016 by Blak92

[mrmackc]

50 minutes ago, Blak92 said:

Be very carefull with once fired military brass. Its mostly machine gun stuff and probably had a sloppy worn out chamber. I had a near case seperation after 1 reload of internet bought MG brass. Certainly had been fired only one time, was still crimped. Search case seperation over on m14forum.com There you can find tricks on how to spot potentially bad brass. After inspecting about 1500 of mine, I tossed about 5-600. Pretty pissed but its better than a face full of gas and metal. You can buy new LC brass under american eagle. Buy a wilson case gauge and drop all that brass in it one at a time before sizing. The ones that wont fit in around the web, or looks like its off centerline, toss em. A small base die will probably only make it worse, thinning that already stressed area even more.

 

This post should be read by anyone contemplating buying cheap military brass for reloading!

[shepp]

1 hour ago, Blak92 said:

Be very carefull with once fired military brass. Its mostly machine gun stuff and probably had a sloppy worn out chamber. I had a near case seperation after 1 reload of internet bought MG brass. Certainly had been fired only one time, was still crimped. Search case seperation over on m14forum.com There you can find tricks on how to spot potentially bad brass. After inspecting about 1500 of mine, I tossed about 5-600. Pretty pissed but its better than a face full of gas and metal. You can buy new LC brass under american eagle. Buy a wilson case gauge and drop all that brass in it one at a time before sizing. The ones that wont fit in around the web, or looks like its off centerline, toss em. A small base die will probably only make it worse, thinning that already stressed area even more.

 

Welcome to the forum feel free to post up in the introduction section of the forum 

[survivalshop]

 

3 hours ago, Blak92 said:

Be very carefull with once fired military brass. Its mostly machine gun stuff and probably had a sloppy worn out chamber. I had a near case seperation after 1 reload of internet bought MG brass. Certainly had been fired only one time, was still crimped. Search case seperation over on m14forum.com There you can find tricks on how to spot potentially bad brass. After inspecting about 1500 of mine, I tossed about 5-600. Pretty pissed but its better than a face full of gas and metal. You can buy new LC brass under american eagle. Buy a wilson case gauge and drop all that brass in it one at a time before sizing. The ones that wont fit in around the web, or looks like its off centerline, toss em. A small base die will probably only make it worse, thinning that already stressed area even more.

 

 No doubt this is a possibility & does happen , but I've used nothing but used Military brass for everything from Belt feds to bolt actions , with a SB Die & have never had an issue with it , of course close inspection of any fired brass is mandatory . I have seen split case necks , but that was before I started Annealing the brass .

Edited April 28, 2016 by survivalshop

[Blak92]

2 hours ago, shepp said:

Welcome to the forum feel free to post up in the introduction section of the forum 

Yup, will do. Ive been lurking for the last month or two gathering info and should have the last few pieces from JP on monday to complete my build. I was waiting on the rain here to subside to start a job and saw this post. Figured I throw my 2 cents in about it.

[Blak92]

34 minutes ago, survivalshop said:

 

 No doubt this is a possibility & does happen , but I've used nothing but used Military brass for everything from Belt feds to bolt actions , with a SB Die & have never had an issue with it , of course close inspection of any fired brass is mandatory . I have seen split case necks , but that was before I started Annealing the brass .

No, its not a definite at all that it will happen using MG brass. Im just one of those people that have those kinds of things happen to them all the time, its just my luck. Just glad it was not worse. Looking for a lighter colored band around the casing above the web and feeling the inside with a bent paperclip (for that band, you can actually feel the dip/thinning really well) are a couple of those tricks though. 

 

I think LC 2004 brass was the year really well known for having that issue. And its still out there for sale.

 

SBS marked NATO brass has not been good to me in my M1A either. They seem to stick in the chamber and have the rim ripped off after firing. Maybe 3 outs 5 times?

Edited April 28, 2016 by Blak92

[shepp]

1 hour ago, Blak92 said:

Yup, will do. Ive been lurking for the last month or two gathering info and should have the last few pieces from JP on monday to complete my build. I was waiting on the rain here to subside to start a job and saw this post. Figured I throw my 2 cents in about it.

No big deal, thanks for finally joining up

[survivalshop]

3 hours ago, Blak92 said:

No, its not a definite at all that it will happen using MG brass. Im just one of those people that have those kinds of things happen to them all the time, its just my luck. Just glad it was not worse. Looking for a lighter colored band around the casing above the web and feeling the inside with a bent paperclip (for that band, you can actually feel the dip/thinning really well) are a couple of those tricks though. 

 

I think LC 2004 brass was the year really well known for having that issue. And its still out there for sale.

 

SBS marked NATO brass has not been good to me in my M1A either. They seem to stick in the chamber and have the rim ripped off after firing. Maybe 3 outs 5 times?

  Now your going to make me look at my brass year , didn't know LC in any year could be bad . I have a lot of it & I think I have one case that has the rings for viewing .

 This is the second sizing or loading of this brass . I'll look at the year . Not even sure this is once fired MG brass , because I have been using a lot of LC M80 ammo for testing a rifle with a FTE completely, issue . 

 

Edited April 28, 2016 by survivalshop

[Blak92]

After reading some more, I might have been wrong about any one particular year. Look over on the m14 forums. Lots of knowledgeable guys over there. Im only 2 years into reloading, so I very well may be mistaken about one year being particularly bad. 

BUT, look up case seperation over there and you'll find a fair number of threads on it. Here are some pics from the same batch of twenty I reloaded with 39.5 IMR3031, first reload of this brass. The one is cut in half, you can see the thin spot that I could feel with the paperclip, but it didnt show much in the way of a ring. The bottom one you can clearly see a ring and can feel the dip of the thin spot by dragging the clip from the rim up to the neck. A secong resizing and firing of that shell would have undoubtedly cased a seperation. Three others you could feel dips. Thats 5 out of 20.

[Mongoose333777]

Sorry for the delay in responding, life gets in the way sometimes.

I cleaned and polished the chamber real well. The military brass now can now be manually ejected, some more easily than others. The IWI brass is the toughest but it will eject.

The NO-GO gauge allows the bolt lugs to partially engage and locks it up. I have to pry the carrier back through the mag well to get the gauge out. 

I want to thank everyone for their input and ideas. I never would have thought that polishing the chamber could make that much of a difference. 

Thanks again,

Ric

[washguy]

Great news !  Way to go....  Wash

[mineralman55]

On ‎4‎/‎28‎/‎2016 at 9:35 AM, Blak92 said:

Be very carefull with once fired military brass.

(Thread jack...)

That goes without saying, but I respectfully disagree with the idea that we shouldn't use the 1x fired military brass. I've reloaded 10s of thousands of 1x military cases fired in five different rifles. The few problems I've experienced were due to improper techniques/procedures on my part and not to the brass. Good procedures (and a good case gauge) are an absolute in what could become but is not necessarily an inherently risky activity.

(Thread un-jack...)

[MikedaddyH]

Inspection of brass is even more important with machine gun fired brass. Lines and creases in the chamber result in deformation of the brass. Just look at the cut open brass showed above. The step in the chamber leaves the 1x brass with a ring of weakness.

Nothing wrong with using 1x machine gun fired brass but be willing to toss some in the scrap bucket .