I have a spare lower that wears an Echo trigger.  It will be an SBR when the stamp gets back but for now will use a pistol brace.

This gun will be a pure range toy, attention getter, and "fun" gun.  Nothing else.  Will also sport an M42K from time to time, so will need room for the 51t mount.

Go.

Sounds like a good plan, I think. Not sure what you are looking for here though, maybe I missed your question.

Really looking for suggestions on how to outfit the upper receiver group.  Barrel, barrel length, handguard, etc.    

Curious what creative minds might come up with and/or things to avoid.

If not suppressed no shorter than 10.5" bzut its all up to you. As for rails, compensators ect it also up to you and what you like. The mission for this rifle is a range toy so make it cool and fun.

10.5 or shorter 300 Blackout (reuse old BCGs and mags!) with a can, 10-12" FF handguard that partially covers the can and a PDW stock?

With the M4-2000, it will have to be 5.56 or smaller bullet.

Since you're wanting to build a fun gun, set up the upper half with a CMT UHPR 9.5 (Mod1/2) with a 10.5" Ballistic Advantage barrel and a nickel boron or titanium nitrided BCG.

I think an Aimpoint H2/T2 on a KAC mount would be a great option as well.  Be sure to use a 51T brake-out for fun at night....

ETA: Whose lower did you decide to SBR?  Depending on who made it, you might have an option on choosing their matching upper.

I vote 300 if it's going to be a sbr.

That is a very, very good suggestion for this particular gun.  Not sure why I didn't think about it.

I'm actually thinking about building an upper around a 7.5 inch barrel.  More flash, more bang, more "holy-shit, who the fuck is that asshole down there and what is he doing?"  51t break-out fits right into that end-goal.

What 7.5 barrels do we like and that run well when set up correctly?

Won't fit my M42K.

10.3"or 10.5" 5.56 - I love mine.  ADCO cut it from a 6920 barrel.  Also using an AAC can.  

super short 9mm

Forgot about that part. Sorry
Get another lower

Get a 30cal silencer

My shortest 5.56 is my braked 10.5 MRP and I have never shot it at night.  I think a 7.5 is going to be detrimental to your M4-2000, even with a brake acting as a sacrificial blast baffle.  I imagine you will still get some wow factor with a 10.3/10.5 and a 51T brake.  Don't forget that it is perfectly legal to have multiple uppers and multiple barrel lengths/calibers for a SBR'd lower.

If you want to go for a classic look, consider building a MK18.  There are always plenty of Daniel Defense FDE MK18 rails on the EE in the $400-500 range.

I'm working on the 30 cal suppressor.

And also know a thing or two about 10.5 inch barrels and Mk18ish uppers.   Was looking to do something different and add some variety.  

Attached File

Nicely done.....

I went with the .30 can first myself, and my corn cob NT-4 is pending as of 25OCT2016.  Hoping to get it before the 4th of July.  Time will tell.

The KAC mod 1 and 2 CQB uppers are really nice, I love my Mod 1.

6.5 grendel upper that you can shoot cheap steel case with and an echo trigger would be fun. Can also use it to double tap hogs.

8.5 inch 6.8SPC. There is a guy on Youtube that did some tests  into gel and he was getting 2550fps with 90gr factory Gold Dots.
6.8 is fucking stupid expensive tho.


https://youtu.be/7kQ4N-fybeU

range toy? sbr?

I say 50 Beo 8" with muzzle break.

That'll get peoples attention!

I built four pistol AR's

7.5"   556
7.5"   9mm
8.0"  7.62X39
10.5"  Aero P M-5 7.62x51

Of the four, the 8.0" 7.62x39 is the most fun for me.

I always start out my range sessions by running a mag through the Aero. After that
no one complains about the noise from the other shorter barrelled pistols.

Attached File



The reason for the funky long stock on the Aero, is I took a SAFE ACT fixed stock, ground off the bottom rail along the entire length, and then wrapped para cord around the entire stock, put a couple of foam tubes on, and presto a longer pistol stock.  It was done as an experiment more than anything else.  For those that don't know a SAFE Act fixed stock is just a standard A2 buffer tube configured with a bottom rail and a standard collapsible stock pinned in place. Internally  the tube is shortened and configured for the  collapsible stock buffer. I was more interested in seeing what benefit (if any) would come from using a longer buffer tube.