450 BM Not Cycling

not knocking your reloading skills, but how long (sometimes reloaders with years experience including me have came across issues) have you been reloading and/or your process?
I have been reloading for 10 years or so and think my process is good but that has all been bolt guns. This is my first go round with a gasser. I posted on here to learn so fire away, no offense taken on any of it. I appreciate all input.
 
I have been reloading for 10 years or so and think my process is good but that has all been bolt guns. This is my first go round with a gasser. I posted on here to learn so fire away, no offense taken on any of it. I appreciate all input.
i've been reloading for 40 years and sometimes i do get a screwup 🤣 , but am able to catch it before something bad happens. i use lil gun also, but for 44mag and 50ae. are you using a progressive press w/auto charge or manual charge? the ar is using a di of which length (gas system length)? my best suggestion for now is load 1 in the chamber and keep the mag empty to see if it holds open from firing? if not, then load 1 in the chamber and 1 in the mag and fire again to see if it stove pipes, double feeds or overrides the next round? with it working/cycling in the beginning the gas tube, gas block and gas key is working as it should. another thing to check is the gas rings and gas key to see if there's no leakage? how much lube or cleaning did you do or use before using the gun? some ar's usually require a fair amount of lube? something to mull over?
 
Just got home and it's dark now so I'll try to answer what I can. I did pick up some factory rounds after work so I'll try them tomorrow.
I have loaded a single round and 2-3 rounds. Doesn't hold the bolt back with one round and with single or multiple in the mag it doesn't eject the first round so no chance of picking up a second. I'm a simpleton reloader and weigh out every charge on a balance beam scale. Just before I posted this I sprayed down the action good with rem-oil hoping to get better results but same. I'll post some more tomorrow on how the factory loads shoot and where they fall. The questions on the gas block size and stuff is over my head so I'll need to look up how to determine those.
 
Just got home and it's dark now so I'll try to answer what I can. I did pick up some factory rounds after work so I'll try them tomorrow.
I have loaded a single round and 2-3 rounds. Doesn't hold the bolt back with one round and with single or multiple in the mag it doesn't eject the first round so no chance of picking up a second. I'm a simpleton reloader and weigh out every charge on a balance beam scale. Just before I posted this I sprayed down the action good with rem-oil hoping to get better results but same. I'll post some more tomorrow on how the factory loads shoot and where they fall. The questions on the gas block size and stuff is over my head so I'll need to look up how to determine those.
since it's a factory build it should work with a wide range of bullets and velocities. bcg might have an issue, but do you know the buffer weight and what spring is being used? is it a carbine or rifle lower? trying to make sure you do have the correct components for the recoil system is all.
 
Might be too light of a load ( under gassed) I'm running 41 gr of lil gun with 225 ftx

I'm running a std carbine spring and buffer, wsr primers with starline brass, fa carrier profile.

I have an 18" bca upper - what length barrel is yours?

Not sure it matters but are you running their radial port brake or side port brake? Mines a side port

Magazine manufacturer? I'm using asc single stack 450bm mags

The hornaday black- 250 ftx ammo cycles my rig fine- try some of that, if it cycles factory ammo I'm guessing your charge is too light- bump it up a bit and see if that helps

Hodgdon shows 35-38.5gr of Lil gun with the 250ftx bullets in their load data

Make sure the hole in your gas block is centered over the gas hole in the barrel-- bca qc can be spotty
 
Last edited:
If factory loads cycle fine and the gas block is all the way open, you may need to change your buffer setup for the reloads to work correctly. The load you listed is near the top of the Hornady chart. Would like to see you post after trying factory ammo.
 
Well, I tried some Hornady Black and got the same results.
18" barrel
??
If factory ammo isn't cycling either, I'd suspect your gas block might have slipped. This happened with my 300 BLK once. I was shooting at the range and then all the sudden, it wouldn't cycle. Pulled the handguard off and saw the gas block had shifted and was covering the gas port. Got it all aligned and tightened down and was then good to go.
 
Bca uppers don't have adj gas blocks that I know of, so like others said, check to make sure it hasn't slipped

Has it ever worked in the past?

Bca actually had very good customer assistance when I had an issue with an upper from them ....if you can't get it working correctly, give them a shout
 
First post said it cycled at first, then stopped. Check gas block as noted by waspocrew above, and check that the gas key on top of the bolt has not come loose. Allen head bolts sometimes are just snug, loose, not staked, or attached with locking compound that won't hold. Look for soot around the top of the bolt/gas key interface. Tighten it back hard and check function.
 
Sounds under gassed to me. Especially after you did the single round test and the bolt didn't lock back on empty.

You can use a dry spaghetti noodle as a "sacrificial alignment pin". Silp a spaghetti noodle into your barrel through the gas port. Break noodle off flush with barrel od. Side on gas block and tube. Rotate the barrel 180°. Adjust gas block until noodle drops into the gas block. Torque down gas block. Break noodle with a cleaning rod down the bore and blow out gas tube from the breach end.

Not knocking bear creek but I wouldn't be surprised if the gas block isn't aligned. Don't shoot anymore handloads or change your handloads until you get cheap factory ammo to cycle.
 

Recent Posts

Top