Armscor ammo not cycling?

[landon223]

So i recently bought a CMMG MK4LE chambered in, you guessed it, .300blk. The rifle runs flawlessly off of 120gr Remington UMC OTFB. I ordered some Armscor 147gr FMJ and they would barely cycle. From what i remember, i would have a pmag fully loaded and have the bolt locked back iirc, when i released the bolt, the round would not fully seat against the bolt. This caused the round to get jammed into the chamber and since it was not fully seated against the bolt face, the round wouldn't fire. Would anyone know why this is happening with armscor and not Remington UMC? I've been looking around for an affordable round to plink with and I've come across Ozark Ordnance, hyperion, surplusammo.com, and magtech's 123gr fmj's featured on surplusammo.com as well. Can anyone tell me if I would have better luck from any one of these sites?

[plant.one]

didnt realize UMC made 147gr... i thought that was 120gr stuff


so 1) different bullet profile.


the 147gr stuff is a good chance its pulls - but even if they're new bullets M80's (147gr FMJ bullets) are not anywhere near top quality bullets so you may have some issues with the projectiles themselves


2nd.. what head stamp brass does armscore use on their ammo?

also what magazines were you using?

[smustian]

The Armscor ammo is out of spec some how. Since it dd not chamber all the way, the bullet may not be seated far enough, the case shoulder is not pushed back far enough or there may be a bulge at the case bottom. Have you compared the Remington ammo against the Armscor? Do you have a Sheridan gauge? Know a reloader near you that might have the gauge?

[landon223]

1) The headstamp on this Armscor is "300AACBLK A P"

2) I was using a combination of Gen M2 Windowed PMags and no-window Gen M3 PMags. Magazines that cycled fine for the first 200-250 rounds of UMC

3) I have not compared the Armscor to UMC.

4) I do not know anyone who reloads and/or has a sheridan gauge.

5) Would you guys happen to know if Ozark Ordnance, Surplus Ammo, or Hyperion Ammo are viable options? I want to get opinions before i start throwing away money trying to find cheap(er) ammo.

[plant.one]

the ozark 147s i got to test weren't spectacular, but would have banged steel reliably. (you may find this to be the case with many 147gr offerings)


however their 135gr offering was pretty impressive for several of us.


one thing to watch when looking at mid-weight ammo (around 150gr) if its 147 its probably m80 bullets, often pulls, which is a pretty poor quality projectile over all consistency wise. but if you can find ammo loaded with a hornady 150gr fmj thats a whole different grade of product and you'll probably be more likely to get better accuracy from it.

here is a saami drawing of the caliber

http://www.saami.org/pubresources/cc_dr ... ackout.pdf

if you have a set of calipers you can begin to explore the ammo you have and see where it may (or may not) be out of spec.

also if you post some pics we may be able to provide some input based on visual clues.

[landon223]

I think the biggest thing I'm looking for is ammo that isn't out of spec like this Armscor. If I can shoot it, I more than likely won't be complaining.

[RAINS]

Might be a bad batch of that ammo. My 8-inch cmmg upper gobbled threw a box of that Armscor 147g stuff no problem. Buy a L5 magazine to try. They seem to work better with short 300blk ammo.
300blk is still pretty new. There seems to be a lot of junk ammo out there. Also avoid fiocchi 150g 300blk. Honestly the best 300blk ammo around here for blasting is the Walmart UMC 120g stuff.
I'll also add in that my 150g FMJ reloads are cheap to make and shoot great. Hand-loading is the only real way to shoot a lot of 300blk.





R

[Larry B]

So i recently bought a CMMG MK4LE chambered in, you guessed it, .300blk. The rifle runs flawlessly off of 120gr Remington UMC OTFB. I ordered some Armscor 147gr FMJ and they would barely cycle. From what i remember, i would have a pmag fully loaded and have the bolt locked back iirc, when i released the bolt, the round would not fully seat against the bolt. This caused the round to get jammed into the chamber and since it was not fully seated against the bolt face, the round wouldn't fire. Would anyone know why this is happening with armscor and not Remington UMC? I've been looking around for an affordable round to plink with and I've come across Ozark Ordnance, hyperion, surplusammo.com, and magtech's 123gr fmj's featured on surplusammo.com as well. Can anyone tell me if I would have better luck from any one of these sites?

A couple of quick checks you can do on the Amscor ammo.

load one round in a mag and drop the bolt from the bolt catch and not from the charging handle. Does it chamber properly? If it does not is the round in the chamber properly just not with the bolt in complete battery or is the round not in the chamber at an angle?

If the round did not go completely into battery was it hard to extract pulling the charging handle? If so then the ammo is out of spec. You should be able to take the upper with the bolt removed and drop a round into the chamber and seat it with very light finger pressure and if you turn it up and bump the back of the receiver on the ground the round should fall out.

I don't shoot any factory ammo so I don't know about the other brands.

[landon223]

So i recently bought a CMMG MK4LE chambered in, you guessed it, .300blk. The rifle runs flawlessly off of 120gr Remington UMC OTFB. I ordered some Armscor 147gr FMJ and they would barely cycle. From what i remember, i would have a pmag fully loaded and have the bolt locked back iirc, when i released the bolt, the round would not fully seat against the bolt. This caused the round to get jammed into the chamber and since it was not fully seated against the bolt face, the round wouldn't fire. Would anyone know why this is happening with armscor and not Remington UMC? I've been looking around for an affordable round to plink with and I've come across Ozark Ordnance, hyperion, surplusammo.com, and magtech's 123gr fmj's featured on surplusammo.com as well. Can anyone tell me if I would have better luck from any one of these sites?

A couple of quick checks you can do on the Amscor ammo.

load one round in a mag and drop the bolt from the bolt catch and not from the charging handle. Does it chamber properly? If it does not is the round in the chamber properly just not with the bolt in complete battery or is the round not in the chamber at an angle?

If the round did not go completely into battery was it hard to extract pulling the charging handle? If so then the ammo is out of spec. You should be able to take the upper with the bolt removed and drop a round into the chamber and seat it with very light finger pressure and if you turn it up and bump the back of the receiver on the ground the round should fall out.

I don't shoot any factory ammo so I don't know about the other brands.

I don't know if it would be variations in the ammo (which makes me wonder about quality) that is causing my issues but with the other 7 boxes of armscor and with the factory extractor spring, 2 or 3 rounds per mag would not seat when pulling the charging handle or dropping the bolt via bolt release. the bolt would jam the round in the chamber and hitting the stock of my gun on the ground would not release it. I had to take a flathead screw driver and gently tap the sides of the round to get it to fall out. After the bcm spring, the rounds seat. however it's a completely different box of ammo. This doesnt make sense to me because wouldnt the bcm spring make it harder to seat? the only problem now is that the rounds do not eject 100%. they are getting stuck on the bolt face. Saw a David Tubb ejector spring and I'm currently thinking about ordering that to see if that helps. If that doesn't, I'm just going to buy in small quantities from Ozark and a few other places to see if they run.

[RAINS]

Sure sounds like out of spec ammo to me. Bummer....

Keep and eye out for rebates and check "THIS" forum often. A member on here posted an amazing rebate deal last spring.(thanks dude!) I bought 400rounds of Remington match 125g 300blk ammo for less than $7bucks a box delivered! Good hunting!



R