Quote History Quoted:
Ive got a QC 10 lower 9mm that I have used three different uppers on it...........gobble up everything in sight.........ran 200 rounds through it a couple of weeks ago.......nary a hiccup............NFA barrel and a Gorrilla machining barrel flawless from the jump........Faxon barrel had the chamber cut too deep and I was getting light strikes..............Mad machinist did his magic.......modified the feed cone and refaced the barrel to get proper head space..............It is my go to\shit hit the fan carbine...................
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Mine is a Sharps Bros "Jack 9". Apparently I had not done the proper research beforehand. My upper is a standard upper, JP Short Stroke Bolt & SCS (purchased together), a JP Supermatch Barrel, and JP Comp. My focus was on the upper assembly as I had it in my mind that the Glock lowers were the cat's meow. I'm experiencing the same condition as the OP. It's not reliably feeding. I came across this video where
BELOW Tim Ubl of Taccom3g is being interviewed and about the
10 min mark he touches on something I feel like is pretty critical information. He mentions JP and Jones Arms having gotten the dimension right and all other glock lower clones are wrong. If yours feeds that well, then maybe QC10 got it right too. Is there any way you can snap a picture of the mag inserted into the lower. I'm guessing that it's closer to the barrel by that .200" Tim mentions.
I'm hoping Taccom's feed ramp will solve my problem. If I had to do it over again, I would go with a dedicated Colt lower or a Colt Mag Block. I still may if this Jack 9 doesn't get to working.
https://www.youtube.com/watch?v=oEJ3xCtXJPg&feature=emb_logo
Edit: Actually Tim Ubl mentions QC10 as having made a very reliable lower.