interesting PMC ammo problem

[Robb Jensen]

A few of my co-workers and I went shooting yesterday at Quantico. One of my co-workers bought a 20" ArmaLite AR (at the shop we work at). It's a flat top (with flat top clamp on factory gas block), SureFire M500 rifle length handguards w/integral light. He added a VLTOR E-Mod complete kit (and is using the stock CAR length buffer spring and CAR 2.9oz buffer) to it and a Trijicon 4x ACOG w/LaRue mount. He replaced the bolt with a BCM unit (kept the ArmaLite carrier). I assembled the SureFires on this rifle about 6 months ago and had to replace the handguard cap to get them to fit.

Anyway he had bought a few hundred rounds of PMC Bronze. His rifle would short cycle (would eject the empty but fail to pick up the next round) about 40% of the time with this ammo and he was running it very wet with oil.

This stuff works in my carbine length guns just fine (I've shot a few thousand rounds of the stuff in the last 6 months or so). I'm thinking it might be like the Radway Green and Serbian stuff where it's pressure drops off too fast and can't cycle a 20" gun reliably.

His ran great with my Federal XM193 and American Eagle 55gr. Another interesting thing is in one of the boxes of XM193 I gave him (2007 stuff) had a M856 tracer round (orange tip) in it (DOH!).

I think this is what we'll be seeing in future times as ammo is getting scarce. (poor quality)

[Lumpy196]

Even more interesting considering what creme-puff loads the American Eagle 55gr has been in the past...

[KintlaLake]

FWIW, the first 400 rounds through my S&W M&P 15 recently were PMC Bronze. There were two short-cycles, both (apparently) lube-related. (We were breaking-in the shooter, too. )

[markm]

I just bought 2 boxes of this stuff at the local Gun store. I'll make a note to run it thru my "fence post" to see how it works.

I still have a few boxes of those Priv short strokers too.

[hgunnerm&p15t]

my s&w m&p15t will not shoot wolf ammo at all- it will eject the used case but will not pick up the new one--it shoots american eagle ae223 like a champ and also seller and bellot 55 grfmj like a champ but will not digest any wolf at all-next to try is pmc and remington umc

[markm]

I put my 2 boxes of PMC in my shooting tote. I hope to get out this weekend. Once I have my fence post at least 80-100 rounds dirty, I'll give the PMC a try. (sometimes marginal ammo will run on a really clean gun)

If I can, I'll try to run some in a full auto 20 incher. Poor cycling ammo really acts up in full auto. I fired some of the Priv M193 in full auto on a 20 incher. Talk about slowing down the cycle rate!

[markm]

Well I finally got the PMC out, and ran it thru a 20 inch rifle.

The weapon had about 50 or so rounds thru it already.... so it was out of the clean and freshly lubed mode.

Anyway, I could tell right away that this stuff was not right. I could feel the cycle of the weapon slow down significantly. Semi auto struggled along with it, but full auto killed it. It wouldn't even complete a 3 round burst.

There's definitely an issue with the powder charge. I only shot one of the 20 round boxes I had. It didn't take long to get the same results that Gotm4 reported above.

[markm]

Took the other 20 rounds I had out yesterday. The ammo ran much better with my silencer mounted on my 20 inch barrel. (same weapon, just as dirty as the previous attempt.)

[mark5pt56]

I've seen over 100k of this stuff fired recently and have'nt seen any issues. Most through 14.5-16" guns 25-30k through 20" Bushmasters.

I've put alot through my Sabre/PK middy and 14.5 Colt, all 100%

Mark

[markm]

Are you talking current production? I know the OLD PMC had a great reputation. But the Current PMC in the Black/Bronze box (.223) is fussy in my 20" bushmaster upper.

[Robb Jensen]

Originally Posted by demigod

Are you talking current production? I know the OLD PMC had a great reputation. But the Current PMC in the Black/Gold box (.223) is fussy in my 20" bushmaster upper.

This new stuff is called PMC bronze (bronze and black box).........a lot of weak ammo out there no, just shot some Serbian M855 that wouldn't cycle a midlength AR (CMMG 14.5" bbl, DD upper receiver w/BCM M16 carrier w/CAR buffer).

[mark5pt56]

I recall shooting some of the old stuff through an Ultra Match that I had. It was amazingly accurate.

Speaking of weak, Radway. I don't know how and why they got/had it, a military unit showed up last year with a ton of it, wouldn't run the M4's at all.

[markm]

Yep!

Radway had some funky batches in there too! I saw that first hand.

+1 on the PMC Bronze... I don't have the box in front of me, but that's the stuff. The good thing is that I only had two boxes and can at least use the brass to make GOOD ammo!

The M855 is that Igman stuff isn't it? Ammoman has a bunch of that on his sight. I never liked M855 at all before... But now look what you have to pay to get Crappy import M855.

[Robb Jensen]

Radway Green is 5.56mm NATO downloaded to better run in the British SA80A2s. It'll run in ARs suppressed.

[markm]

Originally Posted by gotm4

Radway Green is 5.56mm NATO downloaded to better run in the British SA80A2s. It'll run in ARs suppressed.

You'd think that the downloaded M855 would still be hotter than a standard .223 load.... in other words, it shouldn't have any problems cycling a 20 Colt.

But we had bad short stroking issues with it. Several guys on TOS were suffering with it too, but not all of the Radway was problematic if I remember right.

[Robb Jensen]

Originally Posted by demigod

You'd think that the downloaded M855 would still be hotter than a standard .223 load.... in other words, it shouldn't have any problems cycling a 20 Colt.

But we had bad short stroking issues with it. Several guys on TOS were suffering with it too, but not all of the Radway was problematic if I remember right.

It has NATO pressure but the pressure spikes very quickly then drops off very quickly and can't cycle some guns especially those with heavy buffers or midlength and rifle length ARs. I would very likely run in any AR with a Noveske KX3 or suppressor. IIRC my old 11.5" AR with KX3 ran it on fine. I still have about 2500 rounds of it and shoot it when shooting suppressed outdoors and it runs fine.

My old load for USPSA Production when I shot a Glock 34 and had a local ammo sponsor was a 147gr ZERO brand bullet in an undersized 9mm case (to prevent bullet setback which would blow up the gun) he used VihtaVuori N320 powder (sometimes N310) and a Federal match primer. The pressure level of the round exceeds SAAMI and probably NATO specs for pressure but it drops off before the slide even moves and shoots very softly. I ran a 13lb recoil spring (stock is 17lbs) and it felt like shooting CCI Velocitor or Stinger in a Ruger 22/45 pistol.

[markm]

Gotcha! Thanks.

I have a brother in law, new to ARs, who bought some of it. He had convinced himself that the short stroking was a lubrication problem. He wouldn't listen to me when I told him that others had complained about the same thing on the gun boards.

[rhino]

Originally Posted by Lumpy196

Even more interesting considering what creme-puff loads the American Eagle 55gr has been in the past...

What kind of velocities equate to creme-puff loads, by the way?

FWIW, I chrono'd some AE223 on 23-Aug-06 from a 14.5 inch Bushmaster:

Bushmaster, 14.5 inch barrel:
American Eagle AE223 55gr FMJ
Max Vel = 2990 f/s
Min Vel = 2896 f/s
Avg Vel = 2961.8 f/s ... PF = 162
SD = 30.9 f/s

Given that PMC 55gr .223 was notorious in the past for sometimes failing to make minor (when it was 160PF) in 16 inch rifles for a while, I'm guessing it must have been even creme-puffier.

The time period to which I refer was the mid to late 1990s. I know that Benny Hill failed to make the minor PF (160 then) using PMC 55gr at the 3-gun nationals one year during that time. I suspect that such occurances are a primary reason why the USPSA/IPSC PF for minor rifle was dropped to 150 a few years ago.

Which brings me to my point . . . in my experience and that of other shooters I knew, PMC 55gr was alway fairly wimpy, even compared to the other commerical .223 55gr loads (that does not include the no-longer-available-to-us-because-it's-military-surplus PMC M193 ammo ... that was excellent stuff!).

[twodollarbill]

Originally Posted by gotm4

Radway Green is 5.56mm NATO downloaded to better run in the British SA80A2s. It'll run in ARs suppressed.

I thought British ammo wasn't painted green as all their 5.56 was 62gr.
So if it was Green Tip, doesn't that mean it was loaded to US specs.
Or am I just brain farting this one!!!!

I saw that a couple of suppliers were running this stuff at $375/1000,
and discounted in bulk.
My entire supply of M855 is Winchester and I hate to shoot up.
So I thought about picking up some Radway for friends to shoot......

[Robb Jensen]

Originally Posted by twodollarbill

I thought British ammo wasn't painted green as all their 5.56 was 62gr.
So if it was Green Tip, doesn't that mean it was loaded to US specs.
Or am I just brain farting this one!!!!

The British SS109 round isn't green painted because they didn't have a 55gr round and 1x12 twist rifles to keep the SS109 from getting into. The green paint is put there to distinguish it from M193.