Picked up one in a trade for my Dan Wesson 357 revolver.  I got totally screwed, this rifle is a total pierce of crap.  It's no wonder the company went out of business in 2016!  The rifle LOOKS great with it's proprietary upper and lower receivers cut to use Glock magazines. Both receivers are shorter than a standard 223 set.  The upper is cut for a left side charging handle on a proprietary bolt.  The rifle won't even feed FMJ reliably!  The rifle is flawed in that there is no feed ramp to guide a bullet into the chamber.  The bolt picks up a round and moves it forward, the round then has to jump about a 1 inch air space before getting to the barrel breach which is dead flat.  Rounds hang up on the breach face of the barrel shoving the bullet back into the case OR the round ends up sitting at a 45 degree angle between the bolt face and rear of barrel breach. I've tried Glock, P-Mag, Korean mags and nothing works reliably. To date I've had two rounds fire before being fully chambered spraying me with powder and bits of brass.  If anyone is familiar wit his total POS, please advise if there's a fix for the unreliability or do I need to just dump the damned thing.

Tom

I'm pretty new to this game but perhaps sending the barrel out to have the breach ramped like mentioned in this thread. https://www.ar15.com/forums/t_3_66/684105_please_help_me_with_a_9mm_chambering_issue_on_a_new_AR_build.html

Good info.  My barrel breach is dead flat all the way up to the chamber.  The bolt face is dead flat and stops against the flat breach face.  I've also noticed the barrel is bulged/ringed about an inch in front of the chamber so the barrel will have to be replaced.  I wish my lower had some sort of feed ramp but the design is so poor, rounds are stripped from the magazine by the bolt and immediately have to jump thin air about an inch to the rear of the breach/chamber.

I've noticed on the current quarter circle 10 lower receivers including my gsf one as well that they stopped using feed ramps. I haven't had the chance to shoot my build yet but have cycled snap caps perfectly through them. No problem feeding, extracting, or ejecting. I know that is just my limited experience but hopefully that means it isn't such a big deal that yours doesn't have a feed ramp either.

Problem with mine is it won't even feed FMJ reliably!  HP and flat nose bullets rarely will feed in the chamber.  I've polished the face of my bolt and the area around the firing pin to see it that will help feeding from the magazine.  I'll find out Tuesday if the polishing worked when I go to the club range.

A thought just occurred to me.  Can I rebarrel this upper receiver with a 40 caliber barrel and still use the original 9mm Glock lower receiver with 40 cal Glock mags?  Seems like it should work but I'm no expert by any stretch.  I know I'd have to replace the bolt or open up the original (if there's enough room to do so).  The original bolt is completely round and is proprietary to the upper receiver.  My thoughts on doing this is eventually going with a 357 Sig set up for better feeding with the bottle neck cartridge.  Of course the 9mm proprietary bolt would have to be opened up for the 40 cal round.

https://taccom3g.com/product/taccom-glock-lower-feedramp/

Polishing the bolt and bolt face helped feeding tremendously.  Still has occasional hang-ups with 115 grain XTP's but Hornady Personal Defense ammo with the rubberized tip feeds fine, so far.  Factory full copper jacketed RN bullets feed 100% but, plated round nose still hang up and have the bullet deformed by the sharp edge of the breach face/chamber edge.  There's still the issued of the ringed barrel and that will have to be replaced when I can afford it with a barrel that is milled with an integral feed ramp.

I'm currently signed up with Anderson Arms and have the LE/Military discount.  The have ramped barrels that are compatible with Glock and Colt lowers at a vary reasonable price.