-
ODT Gun Show & Swap Meet - May 4, 2024! - Click here for info
Ar won't run steel cased ammo
- Thread starter BIBM502
- Start date
I believe so. It's like a polished black finish.
I can post pictures in the morning.
I’ve got a hypothesis. It’s possible that the MI BCG is losing gas at the carrier bore and/or gas key bore……not a lot, but a bit. With “good” ammo she runs fine, but Tula tends to be weaker (around 2950fps vs M193 at 3250fps).
The MI BCG may not be cycling to the rear as far, so not as much forward spring force.
If the bolt is catching the FTF rounds somewhere on the body, instead of the base of the cartridge, then that’s definitely what’s happening.
If it’s catching the base of the cartridge, but not pushing them fully into the chamber, that could still be the issue.
Could be the gas rings, but I’ve seen brand-new nitrided BCG’s that leaked gas in multiple areas.
As for a “simple fix”, a new BCG is dang simple. It’s a drop-in part. The MI BCG fails to check the boxes for minimum milspec in multiple areas. Upgrade to something like a Microbest manganese phosphate BCG, which is milspec. We sell them at TruPrep, and they’re easy to find online. $100 - $160.
I wouldn’t run the MI BCG, even if it was working. I’d replace it with something that is, at a minimum, milspec and relegate the MI to spare status.
The MI BCG may not be cycling to the rear as far, so not as much forward spring force.
If the bolt is catching the FTF rounds somewhere on the body, instead of the base of the cartridge, then that’s definitely what’s happening.
If it’s catching the base of the cartridge, but not pushing them fully into the chamber, that could still be the issue.
Could be the gas rings, but I’ve seen brand-new nitrided BCG’s that leaked gas in multiple areas.
As for a “simple fix”, a new BCG is dang simple. It’s a drop-in part. The MI BCG fails to check the boxes for minimum milspec in multiple areas. Upgrade to something like a Microbest manganese phosphate BCG, which is milspec. We sell them at TruPrep, and they’re easy to find online. $100 - $160.
I wouldn’t run the MI BCG, even if it was working. I’d replace it with something that is, at a minimum, milspec and relegate the MI to spare status.
I may have missed this, but what length gas system? I’ve run into that issue with midlength and rifle length systems. From what I could gather, the super cheap steel stuff is a bit underpowered to run those longer systems. Put brass in them and they run fine, put the cheap ammo in a carbine length system and it runs fine. This is Just my experience..BUT it hasn’t done it with all of them. I have a middy now that won’t run cheap steel, but my wife’s middy runs it fine so it’s not super reliable data. My thoughts are: the higher quality brass ammo, not m193 but standard brass .223, must be ever-so-slightly hotter, just enough to run it reliably where the steel won’t.
I had kinda the same issue with an AR. Was a new rifle. First time out plinking at targets, and it would shoot brass flawlessly. We had a grab bag of steel cased ammo, and the rifle would jam on the steel cased ammo. Later we noticed that it would shoot the Tulammo steel cases ammo with a "dull" finish just fine. But the Wolf steel case ammo with the "shinny" finish would jam.
Later we discovered that the barrel's chamber was on the "tight" tolerance side diameter, and the "shinny" varnish coat on the Wolf ammo was just enough to add in case diameter to either delay or drag the ejection to where the bolt would not fully retract and properly chamber the next round.
(Dull Cases)
(Shinny Cases)
Later we discovered that the barrel's chamber was on the "tight" tolerance side diameter, and the "shinny" varnish coat on the Wolf ammo was just enough to add in case diameter to either delay or drag the ejection to where the bolt would not fully retract and properly chamber the next round.
(Dull Cases)
(Shinny Cases)
I had this problem with a Geisel supper duty, I swapped out the recoil spring..problem solved
Heres the bcg. Seems like the easiest solution is to swap it out as mentioned. I just remembered that I had also tried the MI bcg with another lower that has a bcm buffer tube kit and same results.
"if it won't eat steel It doesn't deserve brass."
"if it won't eat steel It doesn't deserve brass."
Attachments
The "if it won't eat steel It doesn't deserve brass" maxim holds for AKs, but not ARs. The nicer ones can't shoot brass because they're tuned for specific ammo types. As Shep
cmshoot
said, it's probably some combo of drag, resistance, and undergassing. I have a mk18 with a vltor a5 tube running an H2 buffer and it'll shoot tula because the gas port is drilled out and I'm running a nickel boron BCG. A lighter buffer is the easiest thing to try. And the cheapest. Keeping it well lubed may be enough to overcome the friction. Otherwise, try everything Shep said. He's never steered me wrong
cmshoot
said, it's probably some combo of drag, resistance, and undergassing. I have a mk18 with a vltor a5 tube running an H2 buffer and it'll shoot tula because the gas port is drilled out and I'm running a nickel boron BCG. A lighter buffer is the easiest thing to try. And the cheapest. Keeping it well lubed may be enough to overcome the friction. Otherwise, try everything Shep said. He's never steered me wrong
