Really Happy with the new Quartercircle10 Large Frame Glock Lowers

[Mad Machinist]

Took a trip out to Arizona a while back and met with the great folks at QC10 and made some suggestions for DI friendly improvements to their large frame lower. One of the most significant was to drop the mag catch lowering the 45 mag when installed. Got the new ones in a few weeks back......and the run GREAT. I'm a carbine kinda guy....but I finally broke down and built a pistol lower for testing.....with the old design that was just a small frame with the magwell opened up....the large rame mags being at the same height as the small placed a lot of tension on the bottom of the carrier.....making a 10 inch barrel about as short as would reliably run and only in a carbine configuration.
Enter the new lower.....built the pistol and on went an 11....it ran....then an 8....it ran......and so I pulled an 8 inch off the shelf and cut it to 5 inches......and it ran as a pistol......I'll try and get a video as soon as I can build another.....was talking to a customer and mentioned the 5 inch.....and he gave me a card number on the spot....LOL

here is my 16...........with a Korean high cap...I now have Glock with Kriss extensions......both run well....but I really like the Kriss extensions.

[teutonicpolymer]

Looks great- is this a .45 DI gun in the picture or just plain jane blowback?

[Mad Machinist]

It is a 45 DI, runs flawless with no recoil and I have built 11, 8, and 5 inch barrels and run them on this lower as well..... and the upper will run on a grease gun lower as well....

[bigfeetz]

It is a 45 DI, runs flawless with no recoil and I have built 11, 8, and 5 inch barrels and run them on this lower as well..... and the upper will run on a grease gun lower as well....

Forgive my ignorance but where is the gas port located on a 5" barrel, isn't that right about where a pistol length gas port is?

[Mad Machinist]

A gas operated 45 is a completely different critter than any one with 5.56 experience is used to ........the gas block is very close to the barrel nut.......and I have to make my own, gas blocks, barrels, and gas tubes.....no commercially available components exist....I have bolts and extractors made to 45 specs.....

[bigfeetz]

A gas operated 45 is a completely different critter than any one with 5.56 experience is used to ........the gas block is very close to the barrel nut.......and I have to make my own, gas blocks, barrels, and gas tubes.....no commercially available components exist....I have bolts and extractors made to 45 specs.....

Nice! I would ask how much one of these SBR's run but I have to SBR 2 AR pistol lowers and a M92 pistol before the ATF burns the trust access bridge

[glocktogo]

Subscribed. I've never had any interest in a blowback pistol caliber AR, but a DI? Color me interested.

[Mad Machinist]

Ask away...I'll do my best to answer here...or if you'd like to email me rudyk@maconarmory.com ......be glad to help you with info on all the variations I can.....and an upper if you decide to go for it.