I posted this in the Rimfire section of AR-15 Forums---got 45 views and no comments, so thought that the active guys on the discussion forum would (maybe) appreciate it. Maybe even get one "Nice Build"
Ok, I have been working on this for a long time now. It is my first for several things....
My First AR Build
My First Molycoat
My First Custom
My First Gunsmithing
Accuracy Speaks Shilen 17HMR custom M4 Profile.
YHM Lightweight FF
SE Vortex
Colt Upper
Generic Charging Handle
RRA Lower
RRA LPK
RRA 2-Stage
RRA 6-Position Stock
Norells OD Molycoat
The bolt is a mixture of M16, AR15 9mm, and CZ V-22 all integrated to use 17HMR. It has a modified M16 carrier, Modified M16 firing pin, 9mm gas key, 9mm extractor, 9mm firing pin spring, and standard cotter pin.
The buffer is made out of aluminum and has 1.875" travel.
Here are a few pictures of the bolt and buffer:
Here is the mag that I designed to work with the 17HMR AR, but it needs a little reworking. Hopefully I can salvage it, as I would hate to lose all that work. I built the mag before the AR.
I am still working out the bugs in the system, and AR-Fan and Mongo63A have been giving me some pointers. I thought using a 9mm extractor would eliminate the need to make a custom extractor, but it appears this part caused me a few headaches. I was getting some case bulging and I thought it was due to the mass of the system. I tried 15.3 oz, 14.7, 14.4, and three different spring strengths, and all bulged the case. Come to find out the 9mm extractor wasn't seating properly, and after a few hours of thinking and slow hand filing, everything seats fine now. No bulging at 15.3, 14.7, 14.4 , and now 13.7 oz. Unfortunately, none of them are resetting the trigger yet, so I need to go with a little less mass in the system. I want to keep the stiff buffer spring as I want to assure proper mag action. No bulging all the way down to 13.7 oz, so I figure I can go lower until I see signs of bulging.
I was hoping to get everything ready for April 26 as I am heading on a PD hunt in Montana, but there are too many bugs to work out. I doubt I will be finished.