Keystone Accuracy did a 12" AR15 22LR upper with a Green Mountain blank for me last year and it's very accurate.
I asked Keystone Accuracy to spin up and custom fit me one of his Green Mountain 22 rimfire blanks for my CZ 455. John happened to have an already contoured blank on the shelf from a different project that wasnt being used and offered to use it as a test barrel. While I wanted a 0.90" straight contour I was fine with testing whatever barrel he was gonna spin up.
The test barrel is 0.90" from the action for 2" then tapers to 0.80" at the muzzle and is 18" long. Muzzle is threaded 1/2-28.
The tenon is custom fitted beautifully to my action for zero wobble, leaving just enough clearance for some 609 to glue it into my receiver. I asked Keystone not to mill out the indents on the bottom of the barrel tenon as I was not utilizing the factory set screws and would be gluing it.
Keystone used a Lilja chamber reamer and set headspace to 0.41".
I picked the barrel up the other day, glued it into my receiver and let it sit for 24hr. Dropped it into my MDT LSS-22 chassis, through the Cronus BTR on it and got out to test it today.
18" Green Mountain 416SS Turned Barrel 1/2-28
Lilja Chamber
0.41" Headspace
MDT LSS-22 chassis w/ARCA
Action Bolts torqued to 40in lbs
Timney Adjustable Trigger 14oz
XLR Tactical Buttstock
Vortex PMR 34MM rings
Athlon Cronus BTR 4.5-29x56 MIL
Harris w/Area419 ARCA Adapter
Precision Underground 3D rear bag
I asked Keystone Accuracy to spin up and custom fit me one of his Green Mountain 22 rimfire blanks for my CZ 455. John happened to have an already contoured blank on the shelf from a different project that wasnt being used and offered to use it as a test barrel. While I wanted a 0.90" straight contour I was fine with testing whatever barrel he was gonna spin up.
The test barrel is 0.90" from the action for 2" then tapers to 0.80" at the muzzle and is 18" long. Muzzle is threaded 1/2-28.
The tenon is custom fitted beautifully to my action for zero wobble, leaving just enough clearance for some 609 to glue it into my receiver. I asked Keystone not to mill out the indents on the bottom of the barrel tenon as I was not utilizing the factory set screws and would be gluing it.
Keystone used a Lilja chamber reamer and set headspace to 0.41".
I picked the barrel up the other day, glued it into my receiver and let it sit for 24hr. Dropped it into my MDT LSS-22 chassis, through the Cronus BTR on it and got out to test it today.
18" Green Mountain 416SS Turned Barrel 1/2-28
Lilja Chamber
0.41" Headspace
MDT LSS-22 chassis w/ARCA
Action Bolts torqued to 40in lbs
Timney Adjustable Trigger 14oz
XLR Tactical Buttstock
Vortex PMR 34MM rings
Athlon Cronus BTR 4.5-29x56 MIL
Harris w/Area419 ARCA Adapter
Precision Underground 3D rear bag
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