Just built my first pistol.  300 Blackout Pistol that is!  Finished on Friday, ran a few mags through it on Saturday and Sunday.  

Here's what I've got:
Aero Precision Lower
CMMG lower parts kit (builder's kit)
ALG Enhanced Trigger
Phase 5 'Hex 2' Buffer Tube
Carbine spring/H2 Buffer Weight
Hardened Arms 8.25" upper, 300 Blackout
AAC Brakeout 51T Muzzle Device (compliments the Brakeout on my 16" 5.56 and Blackout 16" 300AAC)
Anderson Nickel Boron bolt carrier set
Lucid HD7 Sight



It is accurate, fun as hell to shoot and a really satisfying build to have completed.  Big thanks to the community here, I've garnered a lot of information from these forums which helped kick this off.

Hope you like it, and hope you can afford enough ammo for it!

Lots of info here. Usually if you have a question, it's been asked a few times before and centralized some great info.

Except my questions... like about making mounts with a upper 1/3 cowitness for guns with folding front+rear BUIS. And no good answers came out of that.

Fine looking weapon you have there. The 300blk is a great caliber for the barrel length you have.

You must have put the AAC on after the pic above. Do you notice the blast concussion much with the AAC? I use a BRT linear comp on a 7.5" and it directs the blast away to make it real comfortable to shoot.

Good question on the blast concussion.  Short answer - yes.

I unfortunately live in a state that does not allow suppressors (for now).  Iowa's elected leadership killed the suppressor bill with midterm election theatrics but allegedly there is a suppressor law in the works.  I'm quietly hopeful that things work in favor of suppressor ownership.

Over a year ago I drank the 300 Blackout Kool-Aid and built a 16" carbine.  The upper came with an AAC Blackout muzzle device.  When I rebarreled one of my 5.56 chambered AR's I purchased an AAC Brakeout for use on the .223.  Now with this pistol build I decided to get another AAC Brakeout with intent of having the 51T ratchet compatibility across all three guns.  

The Brakeout is great for a few things.  It does reduce recoil, muzzle jump, etc. on the .223/5.56, not that it was bad to begin with.  But unless you are directly behind it, the concussion is brutal.  When mounting the upper on this pistol, I  swapped muzzle devices promptly and have only fired with the one pictured.  I noticed that same concussion.  

Knowing what I know now, it might have been foolish to plan for a single suppressor as other manufacturers' are developing really good ones that work across the board.  But I'll cope for now.  If the state legislature cuts the bill down one more time, I might change a few muzzle devices.

And to CavScout8 - The line about affording ammo is all too true!  

I expanded my reloading supplies to incorporate 300 Blackout after getting my first Carbine in this caliber.  I have a good career but these blackout chambered weapons could eat a guy out of house and home if you bought commercially!

-Aaron