I know,I know....BCA

So, I acquired a Bear Creek Arsenal.450 Bushmaster upper. I knew better but I did it anyway. There, I got that out of the way, so please don’t rub it in.

If you’ve even only heard of BCA, you know they’re cheap, which is why I couldn’t resisit and I’m going to pay for it in the end. I bought it knowing that accuracy wasn’t going to be great or even good, but that’s not a problem. It’s surprisingly more accurate than I expected. However, I can’t hardly get it to cycle a 5 round magazine and I can’t get it to lock back on a empty mag at all. At first, I thought it was undergassed, but now I’m not so sure. It is throwing brass at about 2 o’clock. But I think it’s hitting the back of the ejection port (side charging) and throwing it forward. My brother in law took a slow mo video and it appears to be slamming the bolt open pretty hard, which makes me think it’s over gassed at this point. I have used both an H2 and H3 buffer with no change. I just ordered a heavier spring from Sprinco, but now I’m just throwing parts at it.

Other than telling me not to buy junk, does anyone have any thoughts?

Trot line weight....

Just trying to be constructive....




Seriously, don’t have a clue as to help ya out but couldn’t resist......good luck with it!

I have a BCA .450 12-inch upper on my AR pistol.
I’ve not had a problem with it in about 40 rounds.
Pretty accurate as well. I was surprised.

This is a 16", carbine length. What buffer/spring are you using?

Adjustable gas block ?

^^^^^^^

That’s the direction I would go.

Try a different bolt carrier ? , is the bolt catch and magazine operating with firm and positive force - sometimes the mag followers don’t engage the bolt catch too well and it seems like it isn’t locking back but it’s a mag problem....

If the new spring doesn’t work, that will be my next purchase.




I’ve tried 3 different magazines. One is a duramag, one is a AR Stoner (Midway brand) and one is a Lancer 5.56 mag that has been modified with a Tromix spring and single stack follower. All pretty much have the same result. Being a side charging, I don’t have another carrier, and being a .450, I don’t have another bolt.

I go there before messing with buffer springs.

Had basically the same issue used a 30 round AR mag D&H with one of the followers that you made for a single stack I forgot the brand or where I bought them but you can put 10 or 12 rounds in it and it runs great and even though it is a bear Creek it shoots as good as I can hold it
Polymer mags wont work

Bear Creek has a great warranty, maybe send it back to them. My BCA Grendel has never failed to function or provide good accuracy. I did install a rifle buffer and spring.

I thought about this, and I may have to. I was just trying to keep from pulling the scope off and going through the whole process. I have the new spring coming this week and I may throw another gas block on it just for giggles.

First thought is your stupid. Got that out of the way. second thought is your really stupid and have reason to own a gun as stupid as you are. Other than than that your the poster chiled for ANTIFA

I really hope you are joking with this. Either way, would love to take that rifle and shove it so far up your [censored] you can taste gunpowder.

^^ that was uh..... interesting


OP, have you messed with the gas block that is on it at all? Might be misaligned.

So, what is a chiled?

FIFY

Ditto. I have three ARs equipped with BCA barrels and with the right load and a good rest they will shoot MOA or under at 100 yards with good ammo.

Just my .02,
LeonCarr

Someone needs a time out...

I have noticed some preety fugged up comments lately on several forums lately. Odd.

So, as suggested, I put an adjustable gas block on. I started with it almost closed. Wouldn’t even pull the spent shell out of the chamber. Worked on it until it was wide open. Was barely extracting a spent casing. I just happened to measure the gas port and it was close to .072”. After some research, I determined it wasn’t near big enough. Drilled it out to 5/64” and that didn’t work either. Drilled it out again at 3/32” and now it purrs like a kitten. Went through 3 different mags without any failures. All the brass was in a nice pile between 3 and 4 o’clock. In my research, I found that this is a VERY common problem with BCA. We’ll see how it lasts. For now I’m happy but, lesson learned.

I had similar issues with a AR Stoner pistol build in the same caliber i drilled the gas port to .109 and now it functions 100%