Got a Tommy Built KSM/UMP 9mm delivered Friday, trigger is typical, but took care of that off the bat. Firing had several FTF, brass showed significant brass case shavings, figured it was a sharp edge of the feed ramp to the chamber. Fired IMI 124gr FMJ, HK magazine, AAC Evo 9 3 lug mount suppressor, it did group 1 MOA at 25 yards. Brought home, removed the barrel, there was a sharp edge. I then throated/polished the feed ramp, cleaned, re-installed barrel. I then gently manually cycled several rounds thru it slowly..worked great. Will test fire again this week. Before and After throat pics.
Looking forward to hearing more of the review. The feedramp burr worries me though, it seems that Tommybuilts quality control has taken a hit since the introduction of the production T36's. I hope the QC teething issues get resolved as I would love to pick up a T36K.
I also have a Bostic T36, worked flawlessly out of the box. Installed a dual optic, IDZ buttstock. Tried running suppressed with an AAC SR5 .223 can, didn't work well because of to much back pressure, then utilized AAC Sdn-6 .30 cal can today and it worked well.
Range fire update, unit worked flawlessly. Being a double stack feed the the radius/throat job needs to be done 2/3-3/4 L and R up from the bottom of the breach face. Got the trigger pull down to 4.5-5lbs, T36/SL8 I can get about 3.75-4#. The KSM9 Vs a MP5SD is 5.5# dry vs 8.5# suppressor included. The KSM/UMP kick a little more due to the lighter weight and full blow back, MP5's are delayed blow back.