spotting brass fired from a machinegun?

[Echo47]

At a recent gun show, a friend and I were looking at clear plastic zip lock bags of fired brass in various calibers.
I was checking out a bag of 7.62x51 LC brass when a guy behind me said, "don't buy that brass. it's been fired from machine guns."
He was gone before I had a chance to ask how he knew.
Can anyone tell me how brass fired from a full-auto weapon appears and the differences compared to single-shot brass fired from, say, a bolt gun or semi-auto M1-A rifle?
Echo47

 

[Trooperdan]

It was a pretty safe bet... not many semi-auto guns in 7.62x51 in the army these days. Maybe a few M-14's as designated marksmen but by far, most if going to be fired in full-auto if from ther military.

 

[29aholic]

Yeah pretty good chance if it is marked LC (for Lake City) it was shot out of an M60. Now if it is LC Match then chances are it was fired through a rifle.

Not a big deal really, might take a little more sizing and depending on your powder charge you might have to back off your load a little due to smaller case capacity.

 

[colt_saa]

Unfortunately there is no single tell tale sign that will alert you to it coming from a rifle or machine gun.

Certain machine guns have very specific things that are left behind, others have none.

 

[rwsmith]

Sometimes.....

Sometimes auto brass is dented or has heavy ejector scratches. Unless the integrity is compromised and the dents can be ironed out there's nothing wrong with it. If it's a valuable case you can put some effort into it and if you can get it to chamber you can fire form it for the final step if the cartridge will seal itself in the chamber.

 

[bigedp51]

I buy bulk once fired Lake City 5.56 and 7.62 brass and size them once in a small base die to return the cases to minimum SAAMI dimension.

There are times in the past I had to size "some" 7.62 cases with a carbide .45 acp die or a 30-06 die to reduce the body diameter with less effort.

With the older M60 machine gun the case body diameter would expand more and the cases were hard to size in a standard full length die.

Bottom line, if it takes two hands to move the press handle you have fat machine gun brass. This is because Lake City brass is harder and the 7.62 cases are thicker.

Having said that I just finished full length resizing 300 Lake City 7.62 case with a small base die and I did it one handed,

 

[Nevada Ed]

Way back in the 60's when the M60 came out to replace the Browning 30 Cal.........

it was know to us as the .308 NATO round for the M60 and M14 rifle , in the Navy.

At best, I noticed "Belt marks" on the brass cases and that the firing pin marks
were not in the center of the primer, probably from not getting
seated properly in the chamber with the short time it had?

I have no idea what todays brass looks like, 55 years later....
but being hard GI cases, you have your work cut out ahead
of you, when going to resize it.

Even 9mm Milt. cases can be tough !!

 

[Skeet 028]

I was given some LC 308 shot from a mini gun. Very few would size enough to shoot from a bolt action....even with small base dies. I even have carbide dies. I have a friend with an Ishapore in 308. Some would chamber in it. I sold most for scrap. There was quite a lot of it.

 

[cololab]

Many years ago I had less than a whole lot of fun trying to resize some 7.62 X 51 brass that came from the Army, was most likely fired in the M60, and was significantly expanded. I don't know if the cases fired in an FN 240 gun would be any easier to resize.

 

[carpriver]

I got a bunch of 7.62X51 lake city brass, it resized with effort, up trimming the primer hole was more work, I had maybe 50 out of 200 that had to primer pocket crimp trimmed twice. I am firing them in a M1a Springfield squad rifle.

 

[Skeet 028]

On the same vein..I have a bunch of 5.56 shot in M-16s. Came from a military range. Never loaded any...Is there any problem re-loading THAT brass? I have a couple of very large ammo cans full. I use a Giraud case trimmer and it trims after sizing. So...needs to be sized right

 

[amazingflapjack]

Had never heard or considered that-thanks.

 

[randyp]

No problem with the LC M16 brass. I did use a case gauge to insure they were sized properly without oversizing/overworking the brass.
Randy

 

[mikld]

Well, anonymous "information" at a gun show is much like internet info., who knows? If a person looking over your shoulder at a plastic bag of brass can see "machine gun fired" brass, he either is trying to be an expert, or he knows the vendor and where the vendor got his brass, IMO. If the expert can spot "machine gun fired brass" from behind you, you would surely be able to see something "off", even as a new reloader.....

The answers above site some obvious signs of what gun fired the brass (some machine gun brass has length wise flutes in the case body), and a quick question to the vendor may help...

 

[Skeet 028]

Only problem with Military brass except for machine gun fired is swaging primer pockets except with NM brass of course

 

[growr]

I fired many thousands of 7.62 Nato that was sent to the local salvage yard by DMRO....this was fired in M60's....never had a problem with anything...I sized them in my Dillon dies, never a problem, trimmed them, swaged the primer pockets with my Dillon 600 swager...

Although many admonished me to just scrap them as they were most certainly stretched to the point of breaking. Didn't happen...

This was in a SA Super Match M1A that I shot in NRA Service Rifle Matches.


Randy

 

[bigedp51]

I use JP Enterprise case gauges after sizing Lake City 5.56 and 7.62 once fired brass. The diameter of these gauges is closer to minimum SAAMI dimensions. Meaning if the case fits in this gauge it will fit in any chamber.

As I stated in a previous post I just finished full length resizing 300 Lake City 7.62 once fired cases with a small base die. I then checked each case with the JP Enterprise case gauge and all the cases passed the plunk test.

The problem with once fired brass is after sizing the brass wants to "spring back" to its fired size. And if you pause for 4 to 5 seconds at the top of the ram stroke this greatly reduces brass spring back. And pausing will also make your shoulder location more uniform with normal reloads.

Below from left to right are a .223 Wilson and Dillon case gauge and on the far right is the JP Enterprise .223 gauge. And I reversed the cases to show how far the cases will drop into the gauge. And its clear to see the red JP Enterprise gauge is smaller in diameter.

Bottom line I lubed these once fired 7.62 cases with home made lube with lanolin and alcohol and had no problem sizing these cases. The cases were wet tumbled with SS media and any surface dirt and oxidation was removed.

And again if you have to use too much force sizing just use a 30-06 die or a carbide .45 acp die and they will size half of the case body. This will greatly reduce the sizing effort when you follow up with a normal .308 die. (double squeeze play)

I buy my once fired Lake City brass from brassbombers.com/ that has been cleaned and the primer pockets have been swaged.

.308/7.62 - Cleaned, Deprimed & Swaged - LC Only - 100 Pieces $20.00 free shipping
.308/7.62 Cleaned, Deprimed & Swaged Lake City Brass 100 Piece Sample

 

[apollo99]

I have a friend who gives me all his LC 308 brass. It is all once fired through his M-60. It's actually pretty clean and except for the fact they are a little oversized from the generous M-60 chamber, I clean. size ,trim, de-crimp and load as usual. The only thing is the fact that they are nato brass and a little thicker walled than most commercial brass cases I use so I have to adjust my load data.

 

[Echo47]

spotting brass fired from a machinegun

Guys!
As always, you have provided me a wealth of information and I thank you!
At issue which prompted the question was a dealer at a LGS selling bulk quantities of IVI (Canadian Valcartier Industries-a large ammunition supplier to the Canadian Military Services) 7.62x51 fired brass which had been acquired in LARGE bulk quantities and resold in 500 or 1000 piece quantities.
I HAD asked the dealer if the brass had been fired from full-auto weapons or 'single-shot' and he didn't have a clue.
With the suggestions offered in this thread, I am less concerned about the brass being fired full-auto as long as the dealer is offering a decent price for the brass.
Echo47

 

[SLT223]

Linked ammo typically wears the signature of the link rubbing the center section of the cartridge case.

Over on the subguns board some folks have noted very high failure rate in the form of case head separations when attempting to reload for the M60. This is brass fired from the 60, reloaded and fired again in the 60. The thought was loose chamber dimensions allowed for enough case stretch to significantly reduce case life. Maybe not such an issue if re-used in a tighter gun as growr experienced.