Now that I had a (brief) chance to put more rounds through this thing and that I have it 95% where I want it, thought I’d toss up a little review.
The weather is frakking miserable up here with temps in the low 90s, humid and zero breeze. Before I bopped on over to the range, I spent the morning gardening. Thought I drank enough (don’t you always) but being at the range sucked after 90 minutes. The place I went is just an open pit with zero shade but it has some nice metal targets. When they started to get a little blurry, I packed it in.
What I did learn besides nearly stroking out is that this carbine flat out smokes. I love it. Took long enough to build that’s for sure but I had a plan and stuck with it. This and my 16" will be the rifles I would take to a class.
I’ll have to weigh it but I went as light as possible where I could. I may ditch the UBR but not until another stock I want to try comes in and my paperwork for my SF556k can gets approved. It feels butt heavy with the UBR but in the shop with the can attached it feels great so I’ll wait and see.
I had 30 preloaded mags and used them all without a glitch (the rifle that is, not the mags. More on that in a bit). I use Gunbutter lube (grease) that I got from MSTN. Works great and you use very little which is good because it is horrifically spendy.
Components:
UPPER: Began life as a Noveske N4 basic with a 14.5" N4 barrel and SF 556k flash hider. I ditched the handguards and the Troy BUIS but all of the other parts are from John. BUIS is now a KAC 300m. FH is perm attached.
RAIL: KAC URXII customized by Marvin Pitts of Nefarious Arms in Titusville, FL. Several members here have had uppers done by him. Marvin also works for KAC and does just super work as well as being a gentleman to deal with. I sent the upper to him the moment I received it from John. Marvin took a rifle length rail and cut it back as well as carving out room for the KAC front sight/gas block combo, which he also provided and installed. After putting everything together, he welded the FH in place. The bottom rail is still fully removable for an M203 mount.
Rail panels are the new Magpul XTMs. I like them. They snap on securely. They are hard plastic and are not textured. They do make the upper feel a little porky but I have large hands. Try before you buy.
OPTIC: Aimpoint T-1 in an LT mount. Lightweight, rugged, fast. Don’t know what else to say. I have it situated as far back as possible that will still allow enough room for the Aimpoint magnifier in an LT tilt mount.
LOWER: PWA pre-ban. Magpul UBR stock, triggerguard and pre-production MIAD with 3M tape inserts. Geiselle SSA trigger. Run, don’t walk, to get one of these. Might be the single best upgrade you can make to your carbine. Absolutely great and, more importantly, repeatable letoff. Biggest problem is availability.
This is my first use of a Redi-Mag and I have to say I really like it. This is the new lightweight model as you can tell from the cut out. I just have to get familiar and smoother with its function which would have been easier but for my magazines. Which brings me to my P-Mags.
I had recently divested myself of the 16 P-mags that I had. I forgot what version they were but they would not consistently drop out of the majority of my lowers. Recently, I had some store credit coming to me so I let my buddy talk me into trying them again. These are the windowed version and I put ranger pulls on them. I asked my guy if these were the latest variant and he said "Yep...but it's only 10 in the morning, get back to me this afternoon" Oh c'mon, that's funny.
What wasn't funny was that NONE of the 8 mags would drop free from this and the other FIVE PWA lowers I have. Ditto one LWRC and one Stag. Worked fine in two Colts and two KACs. I had to yank them out of the PWAs. These latest mags were the worst of any I have tried. Functioned perfectly but would simply not eject out. I know some get better with use but these will really have to get used to work right. And no, I'm not going to sand them. I own a ton of Magpul gear and really like it but maybe I'm just cursed with P-mags.
LIGHT AND VERT GRIP: I loves the FUG. 
It fits my hand well and is rock solid. Another boringly excellent LT product.
For my light, I went with the SF X300. Great combo of size and lightweight. To mount it where I did, I actually took off the LT mount and went with the rail grabber that comes with the light. This keeps the light as tucked into the rail as possible. With the upgraded version of the excellent SF XT07 tape switch (perm on, temp on and kill switch, THANKS GRANT!!!), I can activate my light with the switch or with my forefinger using the rocker. Couple of repeats on the pics.
The only thing missing is my sling. I use Vickers slings but I’m waiting for my KAC front QD swivel mount to come in so it’s not pictured.
Anyway, I like the way it came out and it certainly works great. Now, if I can just hydrate properly. 
