Colt 6721 not cycling PMC

[BradMacc82]

Hmm, gas-key issues??

 

[rj1974]

Hmm, gas-key issues??

Possibly , I have yet to get into it too much . I was having too much fun teaching my sis and nieces to shoot to let that upper irritate me lol . I just threw it back in the truck and kept shooting .

 

[BradMacc82]

Possibly , I have yet to get into it too much . I was having too much fun teaching my sis and nieces to shoot to let that upper irritate me lol . I just threw it back in the truck and kept shooting .

Understandable.

 

[rj1974]

Understandable.

I'm just going to get a new BCG for it anyway . It is not a FA it is one of the butchered up Colt BCGs .

 

[ALBY]

PMC bronze runs about 200 FPS slower than xm193 on my chrono with a 16 inch tube. But IMO, your gun should run it. I actually load to this spec to reduce wear and tear on my gun in competition.

 

[rj1974]

PMC bronze runs about 200 FPS slower than xm193 on my chrono with a 16 inch tube. But IMO, your gun should run it. I actually load to this spec to reduce wear and tear on my gun in competition.

It should , all the others run it . Im still going to get a FA BCG anyway . I'll use the other one for a ........ hell I don't know , I'll find something to use it for lol .

 

[clandestine]

I took the upper and another proven AR to the range today . The other AR runs them fine so I swapped uppers and the Colt upper still would not run them . I swapped the BCG out of the proven upper and into the Colt upper and it ran them just fine .

So it is time to look at the BCG , it already has new gas rings in it (brownell's).

Just get a Carrier. The Colt Bolt Head is GTG.

Also if it has a Notched Hammer, now is the time to replace it.

 

[rj1974]

Just get a Carrier. The Colt Bolt Head is GTG.

Also if it has a Notched Hammer, now is the time to replace it.

And it has the horrible Colt factory trigger that will be getting dumped .

 

[md123]

PMC bronze runs fine on my Colt 6920 FWIW.

 

[Long1MD]

In my experience PMC Bronze has given me trouble in every caliber weapon I own...tons of FTF's and FTE's. There is a local shop in southern Md that has an indoor range. In order to use their range you had to buy their ammo...PMC Bronze...talk about a crappy range visit.

 

[BradMacc82]

In my experience PMC Bronze has given me trouble in every caliber weapon I own...tons of FTF's and FTE's. There is a local shop in southern Md that has an indoor range. In order to use their range you had to buy their ammo...PMC Bronze...talk about a crappy range visit.

Haven't had that issue myself.

Run it thru Stag's with no issues, D.I. and G.P. models. A few PSA Builds, and a few 6920's as well.

 

[pwoolford]

I had a case of PMC that caused me trouble in a couple AR's. Took a while to catch because I had it mixed in with another case of PMC so one day the gun would run great next trip nothing but FTF/FTE. Finally separated all PMC by lot number and found the problem boxes. If your AR runs all other brands of ammo fine it might be worth trying a different batch of PMC.

 

[ALBY]

PMC is the best cheap ammo out there IMO. When i was developing my AR load i ran all kinds of ammo over the chrono, while testing for accuracy. Most had huge extreme spreads, compared to mine. If memory serves, maybe 150fps or so for UMC and other Bulk crap. In that testing, I ran a 20 round string of PMC and got single digit SD's which is on par with my loads. It was accurate also. But, as I mentioned previously, It is not loaded to 5.56 milspec velocities and if you are running the wrong buffer or spring, your gun may not like it. But this is likely true of any .223 rem (not 5.56). YMMV.