I've been kicking around the idea of one of Ron WIlliams DI pistol cal uppers for a while.
The idea of an upper in either .40 or .357 SIG is very appealing to me and I've had less than pleasant experiences with blowback PC carbines.
Anybody have any direct experience with these uppers? WIll they run on a dedicated pistol cal lower? What kind of magazines are preferred? How about the new .40 cal magazines that RRA is producing?
Any info would be appreciated.
Thanks.

Standard Mil Spec AR-15 Lower or any of a number of specialized
magazine lowers available from outside sources.

I have a 9, 45 and 45 Win Mag Upper by Ron. They're Awesome.
No experience other than watching Ron test firing the uppers in the
calibers you asked about but I'll get there.

Contact Ron for up to date info. He's always innovating new things.

E-Mail Address on this page.
http://www.rmwxtreme.com/Home_Page.html

Dave in Florida

Ron is top notch. I have one of his 9mm uppers. Only bad (This is only for 9mm's and he states it right up front.) is  the 9's are for reloaders only.

Shoot one on Rons guns and you will never want to shoot a blowback again.

Running a DDLES Glock lower with standard glock mags.

What about Ron's DI45 uppers with factory ammo? I thought they were pretty much for reloaders as well, since factory ammo is so dirty? I'm looking at a .45 AR upper soon but I want something that will shoot cheap Wolf steel ammo reliably. I thought that limited me to an Oly blowback upper...  

I can only speak for the 9mm as that is what I have. Sorry.

Thanks!

There are plenty out there running factory through my 45s. Nathen(SCatalyst) here on these boards can help. When I built his upper he met me at the range for his testfire. He followed my breakin instructions & at the end of the day went through 100rnds of WWB without one failure. I dont like the steel cased wolf because i had someone damage their bolt running it. If Wolf is your prefered factory I would sugest the Oly.

Thanks for clearing that up, I'd read on another thread that factory ammo was too dirty for your DI uppers, didn't realize that only applied to the 9mms and not the 45s. If they'll run WWB and Federal that's good enough for me. Wish I'd known that before I raided the coffee can fund for my FNX 45, I may have to put something on the block to raise some funds...

Ron and I have worked with his 45 for quite a while at the range. It appears the dryer you can run the rear of the bolt
the better with factory ammo. I have run all kinds of factory crap through mine and it will get dirty but it only takes a
couple minutes to pull the bolt and clean it. I'm running Mcfarland, 1 piece Gas Rings right now, just to see if that will
help even more. I also reload 45's and Unique Powder seems to work great. Accuracy is Phenominal.

Left target was sight in with unmagnified EOTech, right target was 20 rounds both at 25 yards. Federal Ammo.


Good Luck