New "accurate shorty" upper

[dentron]

I have always liked the idea of a precision sbr. I built this upper to compliment my 10.3" upper on my sbr'd lower. I decided on a 12-12.5" barrel and was going to buy the bcm stainless 12.5" but when larue had their half off barrel sale, i jumped on it.

Component list :

M4 cut upper that came off a Sig, Elephant hooked me up in the pay it forward thread.

Larue 12" stealth barrel with m4 barrel extension : i read on here about the gas port being WAY to big. When i recieved the barrel i checked and yes it was .090" , so i ordered the Black River Tactical custom tune gas port in .070". This should gas the rifle appropriately.


When i installed the BRT gas port there was a bur inside the gas block from drilling it out and had to be sanded a little, no big deal.


Larue tactical low profile gas block : larue uses a 3 screw block and their barrel is dimpled for it, so i ordered on with the barrel.

ALG 10" EMR v3 mlok in Desert Dirt: solid rail and really affordable. I really like the long barrel nut and how tight the lock up is. I dont think there is a rail out there that beats the alg on value. I got this during the blem sale for a steal.


A2 flash hider:
I had this laying around. It works fine and is cheap. Also the 12" barrel with it isnt much longer than my 10.3" with an AAC blackout flash hider on it.

The bcg is a standard full auto that i had laying around. I polished the carrier rails amd replaced the firing pin, cam pin, extractor spring, insert and o-ring with ones from BCM.

Bushnell AR 4.5-18 scope: i picked this up locally for $150. I am impressed with the clarity for the price. The eye relief is really long as you can see by how far i had to mount the scope. I shoot with the stock on notch 2. The eyebox on 18x is not very forgiving, but is still really clear

Primary arms deluxe mount:
Had this laying around too. Its a 30mm and the scope is 1" so i ised some ring inserts. Not the lightest mount, but its solid.

[daddyusmaximus]

Tagged. I'll be watching for the shooting results. Looks like a nice upper. I like how smooth and clean the rail is.

[dentron]

Thanks!
Took it to the range and got it sighted in. Here is a 5 & 11 shot group. Im sure the barrel is more accurate, just the guy shooting haha.

[BC98]

That upper looks like it has a ton of promise. I have always liked the idea of accurate shorty uppers. I've got an 11.5" and 12.5" upper that willboth print sub MOA groups and they take a beating during competitions and carbine classes well.

[famous187]

very nice. i have a 12.5" upper with a 1-4x mtac. i think the SBR with a variable optic is a great tool

[SeriousStudent]

Interesting data on the port size. I bought a set of pin gauges for exactly that reason. It's been fascinating to use them.

Thanks for writing a detailed thread regarding your choices and posting results. I have a Bushnell Tactical 1-6.5x that I am doing the same thing with.

[dentron]

very nice. i have a 12.5" upper with a 1-4x mtac. i think the SBR with a variable optic is a great tool

Thank you. Yeah i think the low power variables are probably a better all around choice and may pick up a leupold mark ar 1.5-4 for it, but i am not at all disappointed with the bushnell for the price.

[HansTheHobbit]

I've always thought that a short barreled SPR would be cool. Shortening a barrel doesn't necessarily have to reduce accuracy that much. It will reduce range, and of course require you tweak the ammo, but there's no reason that an SBR can't be super accurate.

[dentron]

Interesting data on the port size. I bought a set of pin gauges for exactly that reason. It's been fascinating to use them.

Thanks for writing a detailed thread regarding your choices and posting results. I have a Bushnell Tactical 1-6.5x that I am doing the same thing with.

Definately big on checking the gas port. After running it, i think i could actually go down a size to ~.067" if i felt like it. The only thing about the BRT gas port is that its not the easiest part to change (although it is definately do-able).

I haven't used a bushnell before this scope, but i am very happy with the quality.