Machine gun vs rifle M2 ball

[PhillipM]

I've heard the M2 that was linked for machine guns was held to a lower accuracy standard than ammo intended for a rifle. Is there any truth to that statement? I would think they would have come up with another designation had this been the case.

[Art]

I've shot a good bit of both and I frankly can't tell the difference. I think that probably some of the senior masters could but I can't. Of course I suspect a lot of those folks don't shoot much ball ammo anyway.

[rickgman]

Specification allowed ammo with lesser accuracy to be graded as ground machine gun ammo but in practice it appears that most lots of ammo would be capable of meeting both rifle and ground machine gun grades. The grades were: 1) MG# (formerly AC) = aircraft and anti-aircraft machine guns; 2) R# (formerly AC or R) = aircraft and anti-aircraft machine guns or rifles; 3) R = rifles and carbines; 4) MG = ground machine guns; and 5) 3 = unserviceable. And Art, I'm not that "senior" - but I did knew guys who were! Rick

[PhillipM]

Thanks guys. Was this information on a tag in the can or just on paperwork?

[rickgman]

Phil, Once graded at the ammunition plant, the ammo was then configured in a manner consistent with its grade - MG ammo was linked, rifle ammo loaded in cartons or clips, etc. The end user had no idea of the grade per se he only knew how it was configured for usage. Rick

[Maury Krupp]

It's my understanding that once the majority of .30cal weapons were taken out of service the standards were relaxed. They may have even stopped grading beyond the basic pass/fail standard. After that ammo was packed or repacked in whatever fashion was needed at the time.

That's where the de-linked MG ammo in clips came from. I believe the "RR" in the lot number indicates a repack.

The last batch of LC in boxes was commercially de-linked for CMP and put back in the same cans (as evidenced by the markings).

Maury

[raymeketa]

I'm not convinced that any Arsenal or Ordnance Plant graded ammo by an accuracy standard. Does anyone have any proof that they did?

Even the National Match ammunition was not graded that way. All lots of NM were manufactured to the same specifications. It was then packed into cartons and/or clips but the clips were not always loaded with less accurate sub-lots, contrary to what many shooters believe. It had more to do with quantity than quality.

Ray

[Maury Krupp]

A web search for "M2 Ball accuracy standards" turns up this quote from the milspec for M2 Ball (Mil-C-1313):

"Accuracy. The average of the mean radii of all targets of the sample cartridges, fired in standard accuracy test weapons over a range of 600 yards, shall not exceed 5.0 inches for ammunition scheduled for packaging in cartons or clips, nor 7.5 inches for ammunition scheduled for packaging in links."

With Mil-C-1313E 18 Jul 68 the standard was relaxed to 7.5in for all.

So it would appear somebody did some accuracy testing and grading somewhere.

Maury

[raymeketa]

Maury

That's interesting. Do you have a link to Mil-C-1313 ? Or know what the date was?

I would interpret that to mean that the ammunition intended for links was not necessarily loaded to a lesser spec and could very likely have exceeded the 7.5" mean average radius group size.

Ray

[Maury Krupp]

Ray,

I don't have the actual spec, I'm relying on what Bob S has posted here and a few other places. Bob's pretty reliable.

The spec can be had over the net from a couple commercial places but you have to pay :( Don't know if the .gov has it available at any of its sites.

I agree that no ammo was deliberately loaded for any specific purpose. I think after the lot was produced and tested it was packaged as appropriate. For example:

-If it tested good enough for rifle and they needed rifle it was clipped or boxed
-If it tested only good enough for MG it got linked
-If it tested good enough for rifle but they needed MG it got linked
-If it was made after they stopped testing beyond a simple pass/fail it *could* be better than min but there was no reason to care

Maury

[rickgman]

Maury, RR on the cans of delinked LC ammo (generally LC 69) stands for Red River. This ammo was delinked and repacked at Red River Arsenal. They unfortunately tried to pack 280 rds. in enbloc clips into an M19A1 can. This can size was really only able to accommodate 240 rds. in enbloc clips - the result were some dented and bent cartridges. You are correct that later on, a commercial concern (I believe it was Talon) delinked and repacked some cal .30 ammo for the CMP. Rick

[Maury Krupp]

Rick,

OK, not the "RR" but I seem to remember there was some marking on the can to indicate the ammo inside was a repack.

Or maybe not :icon_scratch:

Yes, it was 280 rounds in a 240 round can :(

Yes, it was Talon; I still have some of the boxes.

Maury

[rickgman]

Maury, In a way, RR did indirectly signify that it was a repack. Red River wasn't an ammo plant so any ammo lot number with that prefix was repacked at Red River. If you looked closely, the can exteriors were repainted and then restenciled. Rick

[win308]

One year at Camp Perry, our club received LC M2 ball dated 1969...loaded in clips and packed in cans. NOT ACCURATE ammo at any level. The next year we got 1972 and the year after 1974. The 72 and 74 were both loaded with ball powder and had some kick. You could see the marks of the former MG links on the brass....however, those years were some accurate stuff. So the de-linked LC MG ammo was way more accurate, in my opiniion, than the 1969 that was ment for rifle use.

[Sunray]

.30 M2 is just a U.S. Ordnance Board designation for 152 grain ball service ammo, beginning in 1939. It has nothing to do with accuracy standards. No such thing as .30 M2 MG ammo either. Nobody, in the assorted ammo factories, had the slightest idea or cared what firearm the ammo they made would be used in.

[rickgman]

Sunray, What you say is both correct and incorrect. There was not a specific specification for M2 Ball MG ammo but there most certainly were grades of M2 Ball ammo. The grades were: 1) MG# (formerly AC) = aircraft and anti-aircraft machine guns; 2) R# (formerly AC or R) = aircraft and anti-aircraft machine guns or rifles; 3) R = rifles and carbines; 4) MG = ground machine guns; and 5) 3 = unserviceable. Rick

[John Sukey]

One would think early aircraft ammo would be to a higher standard since A/C machine guns were synchronized and putting a hole in your prop was not a good idea.