Hello,
 I just got my first AR15 and I love it. My Father had purchased a case of some military surplus ammo with "RP" headstamp on it (I think). Anyway, It would not cycle in my 20 mid gas tube length AR. It would only fire a single round and then click. I later found out that it was short stroking the bolt because it was a british surplus and was designed for only firing in short gas tube barrels because it was not "Full Nato power". So my question is are there any other ones I should stay away from? I know LC (Lake City) is OK but who else may have this problem?

Robb

sure the headstamp wasn't RORG? that's Radway Green, RP is Remington-Peters which is usually sold in the green and white boxes marked UMC

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Quoted: considering surplus 223 is pretty much gone.... i don't think your going to ahve anymore problems

Ditto

Quoted: Hello,  I just got my first AR15 and I love it. My Father had purchased a case of some military surplus ammo with "RP" headstamp on it (I think). Anyway, It would not cycle in my 20 mid gas tube length AR. It would only fire a single round and then click. I later found out that it was short stroking the bolt because it was a british surplus and was designed for only firing in short gas tube barrels because it was not "Full Nato power". So my question is are there any other ones I should stay away from? I know LC (Lake City) is OK but who else may have this problem? Robb

British "RORG" ammunition is loaded with a stick-type powder, so it has a different pressure curve, but it is still "full power" ammunition.  Because of the vagaries of different ARs, some like it and some hate it.  You can find the same dichotomy about Wolf...

Knowing more about your particular AR would probably help figure out whether it was actually that particular ammunition or something else; there are a number of potential causes of short stroking, including poorly attached gas keys and not enough lube in (not just on) the bolt carrier.

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Quoted: sure the headstamp wasn't RORG? that's Radway Green, RP is Remington-Peters which is usually sold in the green and white boxes marked UMC

Yep You are right. It is RORG.


My AR is a DPMS lower with RRA trigger. It has a 20" DPMS 1X9 Barrel fluted and a fully floated hand guard. It was built by my favorite gunsmith (also my Brother :) ) and he tried everything to get that stuff to shoot. When he switched to some of his LC stuff, it fired and never missed a shot. I got the story I related earlier from a local Gunshop that builds lots of custom ARs. The minute I showed him the case, he knew exactly what was wrong.

I picked up some Remington UMC 55gr from Walmart to try at the range. I will see how that goes. I was just curious if any other surplus stuff would be made similarly.

Robb

It sounds like your particular AR is just a slightly picky eater.  Stuff like this happens...

My 20" won't cycle it at all.  My 16" M-forgery runs like a top with RG.  Weird.

Is your 20" a mid length gas tube type? That seems to be what some guys think is the problem with this particular load. Like I said, the LC stuff works great. My gun never missed a shot.

My borthers all have 16" barrels with the shorter gas tubes. They all seem to use it fine. Either way, I will just stay away from that load.

Robb

Quoted: My 20" won't cycle it at all.  My 16" M-forgery runs like a top with RG.  Weird.

same here