I MUCH prefer the DI over the blowback....but I own both personally.....most of the reliability issues people have had with DI is due to the wrong lubricant......run one with CLP and I can just about guarantee you'll have issues due to the super short gas system and the low flash point of CLP. I have REGULARLY run 500 plus rounds in a session with no malfunctions through a DI several days consecutively. Also.....blowback is a little tough is running a shockwave brace

I did make a USC adapter years ago for DI uppers and discontinued it, mainly because of the requirement for a paddle release and the unreliability of 20 round USC magazines. The MVB is a pretty close copy...they even duplicated a bend on the early model last round hold actuators that was done to improve function.....but didn't copy the mag catch as well.....basically they have a straight corner on the latch that in the sample I have is a little too tight and breaks the retention tab off the mags. The other issue is mag height, it is the same as the adaptor we made with an added ejector. However it was designed for a DI system and is really a little low for a Colt pattern Blowback. It can be made to run, (I've done it for a couple of customers) but required modification to both the feed cone and the bolt  on the ones I have done. Both had a similar build list and neither could successfully feed a round. Zero malfunctions reported by both customers since the mods.

If you are set on blowback call me at the shop...I only have 5, 8.5 and 16 blowback listed on the website but I can custom cut a 16 for you no problem, with the added benefit of it actually feeding when you assemble it. I don't mind helping folks get other companies stuff running.....(And I do a LOT of it) but I'll guarantee that you won't have the problems if you just start with Macon Armory. After all, a significant ammount of the AR45 products on the market copied a lot of the things we did first. We are the first and only production manufacturer of DI pistol caliber, and the first production manufacturer of a blowback 45 AR as well.....

I have DI uppers and complete conversions on the shelf......and the black Friday cyber Monday code for all uppers and conversions is MABFCM.......it'll knock over $100 off the price of a complete conversion and close to that on an upper. Remember, the complete conversions are turnkey......blowback comes with complete upper that is built on an AERO Precision slick side, magwell adapter, heavy buffer, two 20 round magazines and even a mag loader......, DI is the same except no need for the buffer. By the time you build an upper, but an adapter mags buffer form seperate sources.....it really isn't that much different......except you know it'll run vs having to run the risk of sending send me various parts and components to be reworked to make them functional.

If you have any questions.....don't hesitate to call me at the shop...or message me on facebook.....I prefer the call, lot easier to cover everything in a conversation than doing the three finger peck I do on a keyboard, but I'll be happy to give you a straight answer on any question you may have.

And I still love my CNC Guns AR45 lowers for DI....I just load a 45 tracer in the next to last round in the mag.....when I see the tracer I drop the mag and reload.....

Just reviewed you build list again....7.5 ounce buffer is too light......you'll wind up with powder burns......ask me how I know