Using a used BCG on a new upper?

[AF2001]

Hello everyone,

This is actually my first post. I have tried the search function with no success so I figured I would go ahead and ask. I have an LMT BCG (semi) that was used in a LMT 16" carbine upper. I shot about 500 rounds of M885 through it. Would I be ok in using this BCG in a brand new BCM mid length upper?

Thanks,
AF2001

[Dave L.]

If BCG's were easily available, I would tell you to pony up $130 and buy a new M16 BCG.

As times are tough for parts, you shouldn't have a problem using it.

[bkb0000]

it's a big question mark. i absolutely would not use a BCG with 500 rounds on it in a new fightin gun. if it's just a backyard plinker and you have something else you use for home defense, etc., then you can get away with whatever you want, obviously.

parts, especially the BCG, do mate. the degree of mating and how fast it happens is gonna vary vastly from gun to gun, so there's no great answer as to whether you'll have problems. using a used BCG in a BRAND NEW upper isn't half as bad as using a used BCG in a different used upper, but there's still potential for issues.

if this is a duty or home-defense gun, my advice is to get an overpriced RRA BCG from gunbroker and restake the key.

just some food for thought.

[AF2001]

Well, I just so happen to have a brand new LMT BCG (semi). I just wanted to make sure. If it is going to be any type of concern I will definitely use the new one for the new upper. The reason I was hesitant to use the new was because I was suspect of the staking on the gas key. It is so well staked that the metal has actually split ever so slightly were it makes contact with the screws. Is this good to go or do I need to get this fixed? I want it to be perfect so if it is not in the least bit safe please tell me. Please see the picture.

This a go to rifle. I need it to be as perfect I can get it.

I was also curious why my new bolt had MP marked on the bolt and my old one did not. These are LMT semi BCG's that I brought from a local store.

Lastly, I know this is sticky but if I am running a semi BCG in a 16 inch mid length should I use a C buffer or move up to the H?


Thanks,
Dave

[bkb0000]

the pics didnt pop up on my computer, but it sounds fine. a little split at the stake is normal.

dunno why your one LMT bolt didn't come MP.. your dealer must have jacked it and stuck something else in there

i'd recommend using a C buffer with a middy 16"

[AF2001]

Oh, and thanks for your replies!

[Iraqgunz]

My .03 worth. 500 rounds through a carbine is hardly broken in. As long as you PROPERLY headspace the weapon when you put the BCG in the new upper you should be fine. I did it in the military and do it now when necessary.

As for one of the LMT bolts having the MP mark and the other not, I would venture to say the dealer pulled a fast one.

[bkb0000]

As long as you PROPERLY headspace the weapon when you put the BCG in the new upper you should be fine. I did it in the military and do it now when necessary.

? how do you headspace an AR?

[Abraxas]

? how do you headspace an AR?

I too have wondered this before

[Iraqgunz]

Just in case someone was reading in to what I was saying. As long as you CHECK the headspace correctly with a 5.56 headspace gage ( I use a FIELD gage) IAW the tech manual and it passes then you are good.

The method has been discuess here several times.