Awhile back, I built a Glock mag 9mm AR, using a Joe Bob Outfitters lower (made for them by New Frontier Armory), NFA lower and bolt, and Ballistic Advantage barrel. I could not get it to feed reliably, especially when using ETS Group mags. Even Glock OEM mags were problematic. I talked to Rudy (Mad_Machinist) at Knob Creek about the problem and he told me he could fix the issue with ease. He quoted me a more than fair price of $50, to include return shipping, or $60 if I needed him to disassemble the upper. A few weeks after 'The Creek,' I sent him my barreled upper and a check for $60.

About a week later, Rudy called me to ask me about some red Loctite residue on the barrel nut, which I'd put on it to keep the rail from wobbling. Rudy was worried about damaging the nut when removing the barrel, though I assured him that if it happened, it would have been my own fault and he need not worry about it. Another few days went by and the barrel arrived back home.

I reassembled the upper that night, put it on the lower, mounted my YHM Cobra 9 can, loaded a few mags from different manufacturers (Glock 15 rd, Glock 33 rd, ETS 31 rd, and MagPul 15 rd) with some 124 gr subsonic, and took it out into the yard to test fire. (As an aside, one of the great things about living in the country is the ability to rip off a bunch of suppressed gunfire at 10:30 without disturbing anybody except the dog. I only put a couple dozen rounds through it-just enough to test basic functionality-as I'll take t out this coming week for more range time. I didn't have a single hiccup, which is remarkable, considering how often it would jam before Rudy got hold of it.

If you need work done on your pistol caliber AR to get it running right, you'd be hard pressed to find someone better than Rudy to do the work for you.

Thanks for the good work, Rudy.

Glad to be of assistance....!!

I put another 150 rounds through it today (a mix of 115gr FMJ and 124gr subsonic FMJ) without a single stoppage. That's about 10x as many rounds as I could previously get between stoppages, at best. You did a great job, Rudy.

Rudy made a complete upper for my PSA complete Glock mag lower. I just used one of the factory 30-whatever mags and 1 type of ammo (Fed 115 gr fmj brass case). The thing went 150 rds (all I brought) without a hitch. It was accurate, too. I'll post some pics and report on the rimfire and pistol caliber forum in the next day or two. Satisfied customer here.

This thread could use some photos................

I see I was not the only one complaining to Rudy at the Creek.  

I have just been too lazy to get mine out of the safe and send it to him.  LOL

Now I need to just go get it done this week.

I was running a KVP 7.5oz Stainless Steel  Solid weight Buffer, Purchased one of Macon Armory's 7.5oz Adjustable Weight Buffers, This Buffer uses a Sliding /Moveable weight system, Wow!, what a difference the Macon Armory Buffer is over the KVP. The action is much smoother especially when doing Rapid fire drills. Thanks Rudy, Your the Man.

Rudy... on another topic... thank you for the comment about using set screws to attach a front sight base to an AR... I am building a pinned and welded real Colt M4 barrel, and neither of the front sight towers I have appear to be F marked Colt, nor had the same taper pin dimensions as the barrel... not having a tapered reamer, will give some 8-32 set screws a try...thanks