BCM non blem uppers questions.

[URGILOVERR]

I’ve bought 3 BCM non blem uppers in the past and all 3 of the uppers allowed my barrel to slid in (it was pretty tight) about 1/2 or 1/4th of the way in then stopping and having to be thermal fitted to get it to seat the rest of the way, is this okay? I read somewhere it could be tapered if this happend is that bad? I did buy a blem upper off them and it wouldn’t even start my barrel. I know they give you a note stating it may have to be thermal fitting but is it normal for barrels to start about 1/4 or 1/2 way and then have to be thermal fitted to seat with BCM uppers? I have been using the same DD barrel for all 4 uppers I have tried any info would be great thanks.

 

[_Windrider_]

I’ve bought 3 BCM non blem uppers in the past and all 3 of the uppers allowed my barrel to slid in (it was pretty tight) about 1/2 or 1/4th of the way in then stopping and having to be thermal fitted to get it to seat the rest of the way, is this okay? I read somewhere it could be tapered if this happend is that bad? I did buy a blem upper off them and it wouldn’t even start my barrel. I know they give you a note stating it may have to be thermal fitting but is it normal for barrels to start about 1/4 or 1/2 way and not seat with BCM uppers? I have been using the same DD barrel for all 4 uppers I have tried any info would be great thanks.

Thermal fit is very common. Grease the extension. Heat the upper and slide her home. Let it cool and gtg.

 

[URGILOVERR]

Thermal fit is very common. Grease the extension. Heat the upper and slide her home. Let it cool and gtg.

Thank you, I understand it’s common amongst BCM uppers that’s why I got them in the first place I was concerned about my barrel being able to start about 1/4 to 1/2 of the way before having to thermal fit is this common and acceptable to snipershide ?

 

[TxWelder35]

Heat up upper, put barrel in the deep freeze for a while

 

[jb0311]

Guys he gets how to install a thermofit, that’s not what he’s asking.

OP, yes it’s acceptable. As long as it’s snug after completely fit, you’re fine.

 

[URGILOVERR]

Guys he gets how to install a thermofit, that’s not what he’s asking.

OP, yes it’s acceptable. As long as it’s snug after completely fit, you’re fine.

Thank you, I personally don’t mind it and if it’s gtg that’s great, this upper is amazing like no slop at all to my lower, bcg freely drops at 45 degrees, threads are squared away and gas tube cutout is perfectly centered.

 

[_Windrider_]

Thank you, I personally don’t mind it and if it’s gtg that’s great, this upper is amazing like no slop at all to my lower, bcg freely drops at 45 degrees, threads are squared away and gas tube cutout is perfectly centered.

BCm makes decent receivers. Never had an issue.

 

[021411]

I’ve done it a few times without issues. I just made sure the index pin was dead nuts aligned with the notch on the receiver for obvious reasons before I tapped away with a rubber dead blow.