In a AR, in what order of priority do I troubleshoot problems?

[steve123]

Got a new BCA 350 Legend upper, and guess what, it won't even fire two rounds in a row with factory 145gr Win?!

The Armalite lower I have used for 25 years with no problems in 223 and 6mmAR, etc. Standard length buffer, spring, and tube. ETA - "turned out I did have a SSS/Tubb flatwire spring and Tubber Buffer in the lower."

Near as I can deduce so far is the BCG isn't going all the way back. BCG isn't locking open.

What do you suggest, besides send POS upper back, lol.

 

[redneckbmxer24]

What do you suggest, besides send POS upper back, lol.

Nothing. Send it back and chalk it up as lesson learned. You shouldn't have to troubleshoot function issues on a factory built upper shooting factory ammo on a standard AR lower. You didn't make the parts, or assemble it so it isn't your problem. Get your $$ back and buy something better.

 

[striped1]

At least call the manufacturer to see what buffer weight they spec. It could be you are over buffered or need a different spring or likely both.

 

[Fig]

Fist you make sure it's unloaded.

 

[redneckbmxer24]

At least call the manufacturer to see what buffer weight they spec. It could be you are over buffered or need a different spring or likely both.

He's running standard stuff... If it doesn't run with that it's a pile of shit that changing to a heavier buffer will only make worse.

BCA makes $200 complete uppers. They're junk, that's the problem.

 

[Mute]

It's a non-standard round. If they're recommending that you run normal buffer and springs and you're having problems, it's the upper. I suggest you contact them.

 

[TimK]

It's undergassed or way overgassed, most likely. I assume it doesn't have an adjustable gas block. If you're sure it's undergassed and you really want to keep if for some reason, you could drill the gas port in the barrel one size larger. It's not as scary as it sounds.

If you have a lightweight bolt carrier lying around or a lighter buffer, you could try either or both and see if that solves the problem. If so, you know it's undergassed. Is it flinging the one round it fires across the range, or is it just dribbling out?

 

[Merle]

Sounds under gassed to me. The gas port probably needs to be opened up some.

 

[Ahogue]

Sounds under gassed to me. The gas port probably needs to be opened up some.

Second that but also id be calling them up i want to say a buddy that runs a local gun store had Similar issues with one

 

[Constructor]

Depends on how mechanically inclined you are. You could check to make sure the gas block is aligned over the port, check to see if you have gas leaks at the same time. If you have no leaks and gas block is aligned correctly then drilling the gas port may be the next step.
If you are running an H2 buffer and a SSS or Tactical spring then try a standard spring and buffer.

 

[Zeroit]

Fist you make sure it's unloaded.

Apparently she was left eye dominate and right handed.
Sorry to stray off post. I seen that demonstrated about two months ago in front of combat veterans, I just cleared the 1911 and showed him how to put on the safety.
All I could say was jesus don't that fucking shit put it back in the box and back in your trunk.
He was one of my former engineers.

 

[steve123]

Yes I might send it back but it'd be interesting to see if I can get it running, kind of a challenge to see if I can.

Most of the brass isn't even being ejected, they are still in the action, the rest dribbled out.

My initial thought was to check gas block alignment but see below.

So this might be a stupid question but what happens when a carbine length spring is put in with a standard buffer and tube? Is that a really bad idea?

Thanks for the advice, funny pics, and comments!

 

[MontanaMan]

BCA makes $200 complete uppers. They're junk, that's the problem.

Yep.

MM

 

[Constructor]

Yes I might send it back but it'd be interesting to see if I can get it running, kind of a challenge to see if I can.

Most of the brass isn't even being ejected, they are still in the action, the rest dribbled out.

My initial thought was to check gas block alignment but see below.

So this might be a stupid question but what happens when a carbine length spring is put in with a standard buffer and tube? Is that a really bad idea?

Thanks for the advice, funny pics, and comments!

Edited- somehow I missed that and thought you were asking about a carbine buffer in a standard tube. Swapping springs will change the carrier speed. The carbine spring is stiffer but shorter so I believe it would increase the carrier speed and likely let it travel further to the rear.

 

[Luvman]

Yes I might send it back but it'd be interesting to see if I can get it running, kind of a challenge to see if I can.

Most of the brass isn't even being ejected, they are still in the action, the rest dribbled out.

My initial thought was to check gas block alignment but see below.

So this might be a stupid question but what happens when a carbine length spring is put in with a standard buffer and tube? Is that a really bad idea?

Thanks for the advice, funny pics, and comments!

When you say standard buffer and spring I’m ASSuming you’re referring to a rifle length spring and buffer.

it would seem that the upper is undergassed because the brass is barely being ejected. If you’re up to tinkering with it first check the gas block alignment. If that doesn’t work my next suggestion would be to try it on a lower with a carbine stock and 3oz std carbine buffer.

if it still doesn’t lock back on a carbine lower then I would open the gas port up.

 

[Hobo Hilton]

If you bought something for your computer and it was a "Plug and Play" item that did not work, what would you do with it?

Hobo

 

[bschneiderheinze]

I run a 458 socom with same lower as a 223 224 Valkyrie and 300 Blackout. It is however a rifle length lower. I love how on all these threads the first thing people mention is a a adjustable gas block. Just run your bolt a couple hundred times dry firing and see how it works then. It’s amazing what happens when that bcg gets broke in.

 

[Landon4]

I run a 458 socom with same lower as a 223 224 Valkyrie and 300 Blackout. It is however a rifle length lower. I love how on all these threads the first thing people mention is a a adjustable gas block. Just run your bolt a couple hundred times dry firing and see how it works then. It’s amazing what happens when that bcg gets broke in.

Rifle length lower, all ar lowers are the same, no matter if it’s a pistol or rifle nothing changes about the lower, are you referring to a rifle length gas system?

 

[Zeroit]

If you decide to figure it out yourself great learning experience.
First I personally would start with the gas block/system (consensus says)
Handguard off look for leaks (carbon residue) around the gas block.
Is the gas block tight, is it aligned.
Look at the BCG see if any gas leaks around the gas key and is it staked?
Is the gas block clamp on style or set screws? Good start have some fun.
Couple pictures might help.
How many rounds so far?

 

[steve123]

Okay so apparently it's okay to try the carbine spring in my, I guess you call it, 'rifle length" system of tube and buffer. I'll test fire in a few hours.

If that doesn't work I'll look at the gas block alignment. Not sure exactly how to do that but I'll get on youtube for some tips. And look at the gas key too.

I wonder if there are any other lighter weight buffers in my local gun stores??

Yeah, I could take some pics.

I've only got 10 rounds through the upper right now.

 

[Landon4]

Pics will definitely help, what stock are you running is it collapsible or fixed most collapsible stocks will use a carbine buffer spring and buffer, I think a little research would help you identify what parts your running.

 

[striped1]

Based on your description, in decending order, I would check the , gas block for alighment, gas tube for damage / blockage, gas port sizing and then buffer and spring weight.

 

[steve123]

Well guys I'm encouraged a little.
A few minutes from my property I loaded 3 rounds in the mag, fired away, and all of them cycled, as well as locking the BCG back after the last round.
This place isn't far from neighbors so I didn't want to shoot any more than that but I'll go test a few mags full in a day or two out where I usually shoot.

 

[steve123]

I forgot to mention that I did have a SSS flatwire spring in the lower, not a stock rifle spring, didn't realize I'd changed to that because that was many years ago. It worked great with 223 and 6mmFatRat, but not Winchester 145gr 350 Legend ammo. I've got the stock rifle spring around somewhere so I'll look for it and see if that works.

 

[steve123]

I forgot to mention that I did have a SSS flatwire spring in the lower, not a stock rifle spring, didn't realize I'd changed to that because that was many years ago. It worked great with 223 and 6mmFatRat, but not 350 Legend. I've got the stock rifle spring around somewhere so I'll look for it and see if that works.

Ha, sorry but I've been giving misinformation. I found my old spring and buffer that came with my AR from 25 years ago.

So at least a decade ago I had bought a Tubb flatwire spring and I'm assuming one of his buffers too, because the original buffer was in the original spring, the one I found. I had just forgot that I had bought Tubbs stuff, it's been so long and needed the reminder, these 350 Legend problems did that.
I have no idea what weight buffer the Tubb buffer is but it looks like rifle length??? Anyway like I mentioned up in the thread I've used the Tubb/SSS buffer and spring with no problems ever since I got it.

So I went and bought the Winchester 180 grain soft point 350 Legend hunting load to try. Also brought the Winchester 145 FMJ ammo with me today.
Crazy but the 145 ammo didn't function at all today??!! even though I shot those 3 rounds a few days ago which functioned, and this was with that same carbine spring in the lower, along with the same Tubb buffer. Might be because the ammo sat in the truck in the cold or maybe the spring tension from the 10 round mag being full caused the cycling issue, not sure???

The 180 grain ammo functioned fine with the carbine spring and in, so thought I'd try my old rifle length spring and buffer. That done I loaded up the 10 round mag and didn't have any problems at all. One thing is for sure, the 180 grain ammo has a lot more power to it, thumped the steel pretty good!

Meanwhile, by shooting off the top of my truck hood, I got a zero shooting at my steel, and set the turrets.

I think Winchester made the load too light on this lot# of 145gr ammo. I'm going to put my upper on friends lowers and see if the 145gr works in theirs or not.

 

[steve123]

I tried my friends lower with my upper and the 145's wouldn't work in his either!!! That was pretty bad luck that I got this bad batch of ammo to start and then thinking my new BCA upper was the problem

Well all 40 rounds of the 180 ammo functioned perfectly. 1943 FPS out of my 16" barrel.

Hit the 200M chicken with ease with a nice 2.5" 3 shot group. Knocked the crap out of all our steel in offhand too.

350 Legend in an AR has a neat combination of low recoil, and hard thwack on steel, that I just love, and it doesn't have the loud crack that a 223 has! It's absolutely what I was looking for with my original intent in mind!

Right now I couldn't be happier!

 

[roostercogburn98]

Was getting 2118 average from my 16 inch bolt gun and the 180 factory loads. It’s a fun round, I like mine just need to reload some for it and see what it will do