Top one is a Colt M4 lower, with Colt 14.5 Socom barrel, colt bcg, rock river upper.  Started life as a pinned colt M4, but rather than taking off the welded flashider, I built a new upper.  Has a gieselle trigger.  Vortex Sparc.
Middle is my factory SBR, a DD M4 300 blackout. 10.3 inch barrel. Swapped out the trigger for a Franklin Armory Binary.  Has a SiCo Omega on an ASR flashider mount.  Aimpoint PRO, and a cheap laser /light.  
Bottom is my loose attempt to clone an XM177 weakly.  A2 upper, 12.5 inch Brownells lightweight 1/7 chrome lined barrel.  A1 grip, plastic CAR stock.  Franklin Armory binary trigger in a spikes lower.
I started form 1’s on the premise that with an assault weapons ban, they might be exempted.  However, the draft VA legislation bans SBR’s and silencers specifically.

I've been thinking about getting a DD 10.3 300 BLK barrel.

How do you like it?

The third one rocks! Looks very light and handy.

It's a good gun, but a little spendy at $1800 give or take.  You can build an equivalent cheaper, with a faster turn on a Form 1 vs.  a 4.  It was my first SBR.  I bought the factory SBR and silencer at the same time, then waited about 15 months for the paperwork to clear.  (I knew it would take extra time, thanks to a felony arrest when I was 19).  However, my form 1 submissions have all cleared in 30 days.  I find reloading for 300 blackout to  be challenging, I basically have to gauge almost every case after 3 or more cycles on the brass.  I wind up getting failures to chamber if I don't monitor the brass closely, and even with small base dies I haven't been able to set the press and forget about it.  Not sure if it's because I have a tight chamber, or just because 300 blackout is finicky.  Or maybe I still haven't set my dies up right.

It's my go to - super light weight, accurate.  I don't have a scale, but I'd guess this thing is 6.5 lbs give or take.  It cycles / functions flawlessly.  With the binary trigger you can quickly put a lot of rounds on target.  With practice, the release pull round is only about an inch high at 100 yards, but it took a while to get to that level of performance.  I let a guy fire the binary on a different upper at the range last week, his first round would be on target, and the second was a foot right, and 6 inches high.

I'll probably just buy the barrel and gas block combo directly from DD and build an upper.

Does it seem to be pretty accurate? How far out have you shot it?

I may get into reloading. Would give me something to do!

It is accurate.  the 10.3 inch barrel delivers the same accuracy as a 16 inch build I did.  And velocity between the two barrels is essentially equal, so no reason to go longer.  Barnes 110g and 120g loads work well, as do almost any 110 g varmint bullet.  300 Blackout seems reasonably forgiving from a reloading / accuracy standpoint.  However, you are seriously limited past 100 yards or so, the bullet drop becomes significant, which makes loads that have high SD perform poorly.  It's easy to load subs for, and they cycle well in the DD, as do supers.  A really good all around gun if you want to run a suppressor, or just hunt hogs at 150 yards or less.

Good deal. I'm gonna have to pick one up.

You've got a nice collection of SBRs!!

Whats the stock on the top one? Love them all

It's a LaRue, picked up a couple last year when they were on sale.  Has the same cheekweld as a SOPMOD, better mechanism for retraction in my opinion.  I think I got them for like 40 bucks each during a holiday sale.

I like SBR's. This is all but one of mine. The other is locked in my trunk and I didn't run out to grab it.
Attached File

Top to bottom:
ARX 100
5.56 10.5" AR
5.7 7.5" AR
6.8 12.5" AR
5.56 10" AR (my HD rig)

Left
PS90

Right
7.62x39 7.5" AR

Unpictured
5.56 12.5" mini SPR

Nice!

Thanks! Your's look good too!

Thought about doing anything shorter?

I've got a 7.5 inch 5.56 upper.  But the velocity loss doesn't make sense for the shorter package, and that short length is hard on suppressors.   I recently built a spikes glock lower for 9mm.  Once I prove out that it runs well, I might get a can and do a short 5-7 inch SBR build.  I worry though - all the weight in a 9mm blowback has to be hard on lower parts that were initially designed for 5.56.

I've got a 4" 9mm pistol. I'm really happy with how it sounds and the recoil is fairly mild. I'm currently using the Maxim brace and JP SCS. I may SBR it eventually.
Attached File

we have similar interests!  I'm going to shoot you a PM, would like to be able to bounce ideas off of someone who has such a varied collection.

We have pic threads stickied. Use them.