.300 Blackout issues

[Gobble4me757]

I am running a bear creek upper and psa lower as I was just wanting a cheap beater I could silence. I shot some armscore ammo that would shoot every 3-4 and then jam…I then switched ammo to shoot federal fmjs I think American eagle ammo. It shoots flawlessly. I just tried sighting it in with 200 grain stealth subs and it wouldn't feed the cartridge after each shot. I am using .556 p mags. What do y'all think is my issue?

 

[hillbillyfab]

Is the first time shooting subs with this setup? My friend had trouble getting subs to cycle in his 300 BO. No problem with regular rounds. He ended up swapping bigger tube weights and got it performing correctly.

 

[PickettSFHunter]

BCA'a tend to have feeding issues because they don't do a good job of polishing feed ramps. A lot of people send them back and they will polish then or you can polish yourself.

 

[Lone Hunter]

Sounds to me you have a gas problem. An adjustable gas block might help solve the problem. Difference between the subs and supers on gas flow. You might also change the buffers out if you don't have an adjustable gas block.

 

[EastTNHunter]

Sounds to me you have a gas problem. An adjustable gas block might help solve the problem. Difference between the subs and supers on gas flow. You might also change the buffers out if you don't have an adjustable gas block.

This was my first thought

 

[Gobble4me757]

Yep first time shooting subs…Wasn't really jamming this time as most of it was it would eject the shell most of the time, but it wouldn't grab the next. Like the next bullet was still in my mag. I would then just have to shuck it everytime.

I probably will try to polish the feed ramp first. Do you think when if it's a gas block issue, when I add the suppressor it will help this? I read that subs without a suppressor are more finicky etc. thanks for the reply's!

 

[hillbillyfab]

I'd definitely try them with the can, before I changed anything up just yet.

 

[tntrkkllr]

An adjustable gas block would definitely help

 

[44 mag]

It's either a gas issue or you need a heavier buffer. I would lean towards gas. When I was building mine I was having issues with it as well. It would work with supersonic ammo but the subs just wouldn't cycle correctly even suppressed. Finally got an adjustable gas block and once I got it adjusted correctly I had no issues. Mine was a 7.5 inch not sure your barrel length.

 

[Gobble4me757]

It's either a gas issue or you need a heavier buffer. I would lean towards gas. When I was building mine I was having issues with it as well. It would work with supersonic ammo but the subs just wouldn't cycle correctly even suppressed. Finally got an adjustable gas block and once I got it adjusted correctly I had no issues. Mine was a 7.5 inch not sure your barrel length.

Mines a 16" barrel. I'm with y'all as it's looking like I'm going to get the adjustable gas block. I probably will wait though until I try with the suppressor first though. Appreciate the help!

 

[44 mag]

Yep first time shooting subs…Wasn't really jamming this time as most of it was it would eject the shell most of the time, but it wouldn't grab the next. Like the next bullet was still in my mag. I would then just have to shuck it everytime.

I probably will try to polish the feed ramp first. Do you think when if it's a gas block issue, when I add the suppressor it will help this? I read that subs without a suppressor are more finicky etc. thanks for the reply's!

It has enough gas to eject the spent round but not enough to push the BCG all the way back to pick up the next round. Sounds exactly like what I was having issues with. Putting the suppressor on very well could fix it but then again it might not. You will hear guys talk about ARs being gassy when shooting suppressed. That's because the suppressed adds a lot of back pressure and more gas out of the ejection port.

At least that's how it was explained to me.

 

[Urban_Hunter]

I had the exact same problem with a BCA 16" 300BO upper. The port in the barrel is undersized IMO, and I was going to match it to the gas block port. When I pulled the gas block I realized that from the factory the ports weren't lined up, the block wasnt seated against the ridge on the barrel, blocking about 30% of the gas off. I went ahead and bored it anyways and haven't had a ftc since

 

[Urban_Hunter]

 

[Urban_Hunter]

 

[Grizzly Johnson]

Be sure to check your charging handle… if you're using a suppressor, you want to be using a charging handle to be used with suppressors. It has a lip on it to mitigate the gases blowing through the BCG and out the back around the charging handle. Bravo Co. Mfg. has one and there are a few others as well… I like the BCM gunfighter handle personally.

 

[infoman jr.]

Yep first time shooting subs…Wasn't really jamming this time as most of it was it would eject the shell most of the time, but it wouldn't grab the next. Like the next bullet was still in my mag. I would then just have to shuck it everytime.

I probably will try to polish the feed ramp first. Do you think when if it's a gas block issue, when I add the suppressor it will help this? I read that subs without a suppressor are more finicky etc. thanks for the reply's!

A suppressor will definitely help. In fact, I'd consider shooting subs without a suppressor to be a waste of ammo. Your feed ramp isn't an issue if the bolt isn't going back far enough to pick up the next round in the mag.

 

[Atchman2]

I had to drill out the gas port on my .450 Bushmaster. It is a very common issue with Bear Creek stuff. I changed almost everything else before doing that, but it fixed it instantly.

 

[DaveB]

I had the exact same problem with a BCA 16" 300BO upper. The port in the barrel is undersized IMO, and I was going to match it to the gas block port. When I pulled the gas block I realized that from the factory the ports weren't lined up, the block wasnt seated against the ridge on the barrel, blocking about 30% of the gas off. I went ahead and bored it anyways and haven't had a ftc since

I wonder how many other manufacturer's have this kind of mis-alignment problem. Or, maybe, this is the country boy method of achieving an adjustable block? I don't think so.

Gonna be taking a bunch of AR's apart just to put the issue to bed with our rifles. And none are BCA or BO. Guarantee should you ever be in a pinch and you start having FTC issues the last thing you may think about is that gas port aligned yes/no

 

[Urban_Hunter]

I wonder how many other manufacturer's have this kind of mis-alignment problem. Or, maybe, this is the country boy method of achieving an adjustable block? I don't think so.

Gonna be taking a bunch of AR's apart just to put the issue to bed with our rifles. And none are BCA or BO. Guarantee should you ever be in a pinch and you start having FTC issues the last thing you may think about is that gas port aligned yes/no

When you have someone cranking out the quantities BCA or palmetto has, I assume it's an inevitability at their price point.

Very common for subsonic 300BO to be undergassed, there just isnt a lot of pressure to work with, made worse in a pistol length gas system. An adjustable block would be of no benefit, the port in the barrel is just too small. I've never even heard of an overgassed 300… you're just trying to get all you can get to cycle that thing reliably.

On mine I just found the drill bit that matched the gas block port and opened the barrel port to the same size. Now it's throwing around 4oclock at 1015fps on a 220gr Barry's. Rock solid dependable, just took some tweaking

 

[Yota]

Without an adjustable gas block, hard to have one setup that works flawlessly for supers and subs. Buffer tube is a quick fix, lots of gassing possibilities, also could be QC issues w parts like those. Will be trial and error to fox. Find ammo it likes and stock that.