20 inch BCM upper with Stag A2 lower?

**allthelumens** · 11-10-15, 01:51

I'm pretty new to the firearms scene, as only having ever owned one rifle (a S&W 16 inch M&P Sporter). I have since sold that carbine as money was tight. I've been doing as much research as I can for my next purchase (I might attempt an actual build one day.) This rifle will be used primarily for training and home defense. I wanted some input into this subject as to what I should include and or stay away from? I am thinking of going with a 20 inch BCM upper and Stag arms A2 lower. Thanks in advance.

**Iraqgunz** · 11-10-15, 02:52

Why do you want a 20" especially when you indicate for home defense and training? A 16" carbine is more than sufficient and more compact for such a role. There are lots of sales happening right now. Take a look at these uppers and then find a lower of your choice.

http://sionicsweaponsystems.com/store2015/

**allthelumens** · 11-10-15, 10:18

I will be honest I have gotten a lot of information from guys on Youtube but in particular Reid Henrichs... he does a video about his AR setup and I agreed a lot with what he said so I figured that could work for me.. and in close quarters that 4 inches probably isnt going to make much of a difference velocity wise I'm thinking correct? As far as optics go I am definitely leaning towards an Aimpoint or the Trijicon MRO.. Also for you guys with more experience... is it paramount to have a light that you can operate ambidextrously? I will definitely take a look at the 16 inch uppers.

**SLewis** · 11-10-15, 10:32

A 20 inch upper on an A2 lower will be significantly longer than a 16" upper on a collapsible stock. There is more like a 9 inch difference in overall length with stock fully collapsed.

Get a bcm 16" upper and, if you're really strapped for cash, a complete palmetto state armory lower which can be found for under $200.

**Malamute** · 11-10-15, 16:02

Originally Posted by SLewis

A 20 inch upper on an A2 lower will be significantly longer than a 16" upper on a collapsible stock. There is more like a 9 inch difference in overall length with stock fully collapsed.
.

I believe the difference is 7 1/4" from my measurements.

I cant argue with the reasoning of most regarding a carbine for home defense, though my favorite all around type for shooting is the 20" rifle.

**Circle_10** · 11-10-15, 17:05

If you are pretty sure you want a fixed stock, I went this route with one of my ARs....fixed A1 stock but a 16" mid-length upper. Shoots nicely. I love Magpul's SL handguards and would put them on this gun if it didn't require swapping out the triangle handguard cap with a round one.

I even did this for a while - lightweight carbine upper on a fixed stock lower. The setup didn't like PMC bronze for some reason I never determined but it ate steel cased stuff with no issue, the upper has since been stuck on a carbine lower and spray painted but I do find the shorter barrel/fixed stock combo to be enjoyable to shoot. The dark blotches on the barrel are from where a sling melted to it following a firing session, Oops.

**RWH24** · 11-10-15, 10:37

Ref question on light placement. Mine is where I have the best control with my support hand. Not easily manipulated by my strong hand and I am right handed. If you were clearing buildings with lots of halls and doors where you would change sides, YES I can see this being advantageous. For my home, I am GTG.

**samuse** · 11-10-15, 15:55

A Stag A2 lower is every bit the equal of a comparable BCM. You would have to go Colt to get a better receiver extension.

I'm with everyone else on the 20" A2 setup. It's a dinosaur by today's standards. An adjustable stock and a 16" barrel makes worlds of difference in handling ease.

**Business_Casual** · 12-02-18, 18:35

Originally Posted by allthelumens

I will be honest I have gotten a lot of information from guys on Youtube but in particular Reid Henrichs... he does a video about his AR setup and I agreed a lot with what he said so I figured that could work for me.. and in close quarters that 4 inches probably isnt going to make much of a difference velocity wise I'm thinking correct? As far as optics go I am definitely leaning towards an Aimpoint or the Trijicon MRO.. Also for you guys with more experience... is it paramount to have a light that you can operate ambidextrously? I will definitely take a look at the 16 inch uppers.

Wasn’t he a Marine? Maybe he spent a lot of time behind a 20” barrel and that formed his opinions.