BCM receiver extension canted

[msedward43]

Ok, this is NOT my freaking week. I'm about ready to pop a couple of shots of vodka and say "this is the end of the week"

Anyways, after I got my receiver fixed at Sionics, I decide to order a BCM upper to go along with my 2 Spare BCM factory lowers that I got during pandemic as a "just in case Biden goes nuts" scenario.

well, I pull out the first of the two lowers to toss on my MOE SL stock I just p icked up and noticed that the receiver extenion is noticeably (at least to me) Cant'd . Enough to where you can definitely see it with the naked eye the second you put your butt stock on.

since this is a factory lower and not one I built, is this enough to bug BCM about fixing or simply leave it alone as an OCD trigger

[grizzman]

Option 3 is to fix it yourself. Should take less than 20 minutes if you have the proper tools. If you don’t have the proper tools, th is is a good reason to acquire the proper tools.

[msedward43]

Option 3 is to fix it yourself. Should take less than 20 minutes if you have the proper tools. If you don’t have the proper tools, th is is a good reason to acquire the proper tools.

I used to, sadly an injury to my left arm (my tool arm) left me with slight trembles at the finger tips when I try and do fine moter skills things like line up parts JUUUUUST right etc. It's not horrible but it's just enoug to where I don't trust myself trying to re-line it up just right.

for this in particular I was just wondering if it was something that happens and BCM will say "pfffft, it's just your OCD dumb@ss" or whether it's something they would consider fixing.

[the AR-15 Junkie]

Ok, this is NOT my freaking week. I'm about ready to pop a couple of shots of vodka and say "this is the end of the week"

Anyways, after I got my receiver fixed at Sionics, I decide to order a BCM upper to go along with my 2 Spare BCM factory lowers that I got during pandemic as a "just in case Biden goes nuts" scenario.

well, I pull out the first of the two lowers to toss on my MOE SL stock I just p icked up and noticed that the receiver extenion is noticeably (at least to me) Cant'd . Enough to where you can definitely see it with the naked eye the second you put your butt stock on.

since this is a factory lower and not one I built, is this enough to bug BCM about fixing or simply leave it alone as an OCD trigger

Calling Cliff556 lol!

Painful! As to the price and only 1 left in Stock, but alas I must admit I bought 2 of these about 2 years ago and they flat out work PERFECTLY, as do the "whole lot" cheaper Blue versions..

https://shop.taconesports.com/produc...e-jig/#reviews

[Disciple]

The cheap blue version. https://www.shootingsurplus.com/ncst...ver-viceblock/

[msedward43]

Calling Cliff556 lol!

Painful! As to the price and only 1 left in Stock, but alas I must admit I bought 2 of these about 2 years ago and they flat out work PERFECTLY, as do the "whole lot" cheaper Blue versions..

https://shop.taconesports.com/produc...e-jig/#reviews

LOL! yeah, Cliff and I were just talking about that on TOS

[w3453l]

Have you tried emailing them? Attach the same photos you posted in this thread and see what they say. Worst case, they tell you to piss off and you go to plan B of just fixing it yourself. Or just fix it yourself (I know you mentioned your injury).

**Slightly off topic, but I think worth mentioning here, I’ve built a few lowers using FCD receiver extensions and end plates. They all naturally lined up perfect without any crazy effort or extra tools.

I don’t know if they have some extra feature that makes it this easy. I’ve never been into assembling AR’s. I’ve always just bought complete lowers, so I figured they all line up perfectly just by design.

I realize what I said might be a “no shit Sherlock” statement. But I didn’t know canted extensions were a thing and didn’t realize they had jigs for installing them until I stumbled upon it recently.

ETA: To answer your post more directly, yes I would be bothered by that enough to fix it myself or have them fix it. Not so much because it looks wonky but I imagine that’s going to become annoying when shouldering if you’re wearing any sort of PC.

[msedward43]

Have you tried emailing them? Attach the same photos you posted in this thread and see what they say. Worst case, they tell you to piss off and you go to plan B of just fixing it yourself. Or just fix it yourself (I know you mentioned your injury).

**Slightly off topic, but I think worth mentioning here, I’ve built a few lowers using FCD receiver extensions and end plates. They all naturally lined up perfect without any crazy effort or extra tools.

I don’t know if they have some extra feature that makes it this easy. I’ve never been into assembling AR’s. I’ve always just bought complete lowers, so I figured they all line up perfectly just by design.

I realize what I said might be a “no shit Sherlock” statement. But I didn’t know canted extensions were a thing and didn’t realize they had jigs for installing them until I stumbled upon it recently.

ETA: To answer your post more directly, yes I would be bothered by that enough to fix it myself or have them fix it. Not so much because it looks wonky but I imagine that’s going to become annoying when shouldering if you’re wearing any sort of PC.

yeah, I'm going to send an email to them now. I started the thread mostly as a "hey guys, is this severe enough for me to bring to their attention? or will they just tell me to bite a sock off of this amount of cant" as I can be sometimes a little over perfectionistic.... might as well hit them up and see what they say since it seems to be severe enough to irritate most people


as for receiver extension cant being a thing. Yeah it easily can be. there's always tolerancen stacking in the fitment of the end plate little tang that fits into the receiver extension groove. you can usually clock it 2-3 degrees either direction with many of them and if you aren't holding it still when torquing down, the receiver extension can slip a bit and clock to the left as it's torgued down. That can be an issue if there is too much play between the parts, OR if the person puts some heavier than normal torgue onto the castle nut. That means it actually torgues the extension around and gouges the threads onto the end plate "tang" a bit allowing the buffer tube to turn further than it's supposed to. Kind of the RE version of over torquing a barrel nut and having the FSB becoming canted. It's almost impossible to be PERFECTLY level and on point (if you look very closely at most receiver extensions there is like 1/2 to 1 degree cant either direction) but I haven't seen it that much before on a factory lower from a well known mfger

I had it happen a few times with my own receivers back in the day, but never with a higher end one like BCM or SOLGW or DD. I sadly didn't look at the receiver extension when I got it because I had about half a dozen BCM lowers and never seen it before.

[prepare]

It's unfortunate that it slipped through their QC but it's an easy fix. Contact them and I'm certain they will make it right.

When that happens the tab on the end plate usually damages the threads on the buffer tube so in order to fix it right they would have to replace the buffer tube and end plate.

[msedward43]

It's unfortunate that it slipped through their QC but it's an easy fix. Contact them and I'm certain they will make it right.

When that happens the tab on the end plate usually damages the threads on the buffer tube so in order to fix it right they would have to replace the buffer tube and end plate.

yeah, I'm going to make mention of that in my email. when when it rotates that much around the only time I had that happen in the past was when I was a newbie and used he-man hulk power and over torqued it resulting in that thread gouging.

x fingers they decide to fix it themselves as my tool hand isn't in the shape it was 7 years ago when I was rolling my own (amazing what happens when you blow 2 discs and crack a vertebrae in a weight lifting accident lol)