AR15 BCG won't lock back

[ar15barrels]

A rifle length gas system needs a rifle length buffer and tube.

False.

[pterrell]

Well if what I had always been told is wrong then alright. nothing wrong with learning something new

[kcstott]

I've read around and gotten mixed responses. Like I said it was fine before the barrel/gas system swap. I hope I don't have to take the tube off. I already staked it on

Yeah but there are millions no billions of experts on the interweb

When it comes to AR gas systems and buffer setups Randal is the authority hands down, I've learned a lot about the AR from him, Stuff people wouldn't even begin to think about.

[selfshrevident]

Update

Took it to the range after a good cleaning and with some warmer loads but still the same issue. So I took the BAD lever off and presto, she functions 100% now. I wonder why that would cause an issue... oh well it's fixed now.

[ar15barrels]

Took it to the range after a good cleaning and with some warmer loads but still the same issue. So I took the BAD lever off and presto, she functions 100% now. I wonder why that would cause an issue... oh well it's fixed now.

Mis-located bolt catch pin.
The bolt catch is likely sitting closer to the receiver than it should.
This causes the bad lever to run into the upper receiver when the bolt catch is engaged.
The limited amount of engagement was NOT enough to properly retain the bolt.

I bet if you try a different lower with that upper that it might work just fine with a bad lever.

[6mmintl]

You might need to straighten out the gas tube that is inside upper receiver as they are sometimes bent/curved from shipping or installation.

Place receiver upside down and with BCG slide forward till it just hits/telescopes over gas tube tip looking for any side movement of bolt (twisting) or tube, if you can see tube thru handguard, look to see if tube air gap (with light on opposite side) against barrel, increases or decreases indicating tube is bent/twisted from installation. You can bend the tube tip slightly with a wide bladed flat screwdriver and repeat the test until no more movement.

Best to do it before putting on handguard but tough to see with tubular free float tubes.

Its always a good idea to inspect the gas pickup tube in the bolt carrier to see if cone guided end is not dinged. If so file/polish to smooth.

[sixgunner]

If you put the bad lever back on try moving it a little. Try it out with a empty mag and see if the bolt locks back. If you move the bad lever a bit you may be good to go.

[Kmai24]

I once had the same problem and I was thinking it was buffer spring issues (maybe too long of a spring or too short) so I went out a bought a few springs, swapped them back and forth and still was having an issue with the bolt not locking back. Took me awhile to consider that I was also hand loading so I decided to up my charge and waala..bolt locked back on every round. Try that and if your aren't already, run your bcg a little wet

[kcstott]

I once had the same problem and I was thinking it was buffer spring issues (maybe too long of a spring or too short) so I went out a bought a few springs, swapped them back and forth and still was having an issue with the bolt not locking back. Took me awhile to consider that I was also hand loading so I decided to up my charge and waala..bolt locked back on every round. Try that and if your aren't already, run your bcg a little wet

you can spec out a spring with a tape measure you know??

proper research would have saved you time an money

[Kmai24]

you can spec out a spring with a tape measure you know??

proper research would have saved you time an money

Yeah I could of done that, but I did a rookie move..went and snipped some coils to see if that was the problem (I know Ill get flamed for that) but like I said, rookie mistake. Sometimes you shouldn't believe what you read on the Internet. It didn't ruin my rifle but like many have stated, "it's just a band aid to cover up the problem"