AR-15 won't cycle after using cast bullets

[hornady308]

I have a standard milspec grade AR-15 with a 300 Blackout barrel. The rifle was working great with copper jacketed bullets, but I tried some cast bullets and now the action will not cycle at all. I went back to firing copper jacketed bullets but the action still would not cycle. I could use a little help with where to look for the trouble and what to do about it. Thanks for the help.

[ShooterAZ]

My first thought would be a plugged gas tube/port. More info would be helpful, such as the load you are using.

[gnostic]

Try a process of elimination with the gas system. I'd start with the bolt, gas key etc. Try squirting solvent thru each component until you find the obstruction.

[country gent]

Im thinking lube or other contaminant in the gas tube restricting flow of gas. I would pick up a new one and try it, ( gas tubes are a real pain to clean of hard deposits). or clean the old one. I used to se long pipe cleaners for this. Soaking in solvent or an ultra sonic cleaner will work also

[cwlongshot]

I agree start with gas system...

OOH forget about cleaning the gas tube... Just buy a new one be sure you get a couple roll pins too. The tube is CHEAP compaired to the PIA job of cleaning one...

Hopefully your gas block can be cleaned. its doubtful lead got to the gas key, but stranger things have happened.

Good luck

CW

[lefty o]

if it worked before you shot lead thru it, but now doesnt, id be looking at the gas tube/gas block.

[oldracer]

AR's and those are not made to shoot un-jacketed bullets. Due to the high heat generated I agree that there is lead build up. I also see folks at our range trying to shoot steel cases and they don't work well either.
John

[Tripplebeards]

My first thought would be a plugged gas tube/port. More info would be helpful, such as the load you are using.

Yep

This us why I don't run cast through my ruger carbine

I'm guessing if your boolits were powder coated you'd have a better chance of it not plugging.

[popper]

Just put a small hose on the gas tube and blow through it (or compressor if you have one) I've had the gas key full of junk and it still would cycle, hole in the junk was same dia as barrel port. Soft alloy with subs or supers may plug the barrel port. Bolt rings may get stuck with accumulation but then hand cycling is difficult. PC is OK even for PB supers. Hard lube can accumulate in the GB but solvent will remove it.

[marek313]

The only time i had any lead in my 300AAC with PCed cast bullets was around gas tube connecting to the gas key and it was sticking when manually cycling the bolt. I'm guessing you have some leading inside the gas system somewhere that prevents gas from cycling bcg. i didnt have any blockages like you but I would start looking there as everyone suggested.

[too many things]

dont use cast will fix problem

[Moleman-]

I've got a few uppers that I use with lee tumble lube bullets with alox and then dusted with mica which can really clog things up with lube. The bolt carrier group especially gets dirty when you put a few hundred cast loads through it. While you're shooting it and it is warm the excess lube seems to be blown out of the vent holes in the carrier, but after it cools if you don't clean it when it's real dirty it can cause sluggish operation the next time up until it gets warmed up. Never have replaced a gas tube yet as full power jacketed loads seem to clean it out.

[Hamish]

A couple of the comments in this thread make me want to slap their Momma's.

I'll keep running cast in my AR's, thank you,,,,,. We know that if you fire unsuitable loads, no matter the action type, crud/leading can occur.

[hornady308]

Problem solved...it was a plugged gas key. I have fired cast bullets in lots of semi-auto pistols, including a .44 Desert Eagle, and never had a problem. Same for semi-auto rifles such as an L1A1, SKS and AK. Never a problem. I personally have no interest in owning any firearm that cannot be uses reliably with cast bullets. Thanks for all the help.

[oldracer]

I agree with not owning any firearms that can't shoot cast bullets...…..all I own are muzzle loaders!

[hornady308]

BTW, the blockage in the gas key turned out to be a blown primer. The problem had nothing to do with cast bullets and everything to do with a crappy job of reloading.

[Smoke4320]

Glad you got it worked out .. Sometimes gas issues can be difficult to figure out

[Boolit_Head]

That is odd, I've got a blackout that I exclusively shoot cast with and without a suppressor with and it has yet to hiccup.

[popper]

BTW, the blockage in the gas key turned out to be a blown primer. How did that occur? Just curious as it seems like a 1M:1 chance.

[Boolit_Head]

Blown primer makes more sense than cast plugging it. But dang the chances that it would end up there!