Front sight unscrewed and set aside.
6.5"from muzzle to front edge of the painter's tape.
Loosened the barrel band screw and the barrel was unscrewed from the breech block.
Shank is threaded M10 x 1.5mm
Aluminum packing shims in the chuck jaws to protect the bluing. I did have some concerns at this point about shortening the barrel and losing the choke at the muzzle.
Rolled the dice and plunged in with a parting tool.
Rather than just finish the muzzle and be done with it, I turned down a portion of the barrel to 0.495"
Used a Taig die holder in the tailstock and started threading the muzzle 1/2"-28.
Couldn't hold the barrel tight enough in the chuck to finish the thread, so it was transferred (die still engaged) to a vise with padded jaws. Also swapped to a proper die holder for additional leverage.
Finished the thread.
The 1/2"-28 thread allows use of the myriad AR-type rifle muzzle devises.
Back to the lathe to cut a relief at the end of the thread.
And re-crown.
Threaded on a long AR-15 muzzle brake to add weight and stability. Could've used a shorter brake, but I find the weight distribution now ideal. Even with the added length of the brake, it's still shorter than what we started with. It comes to point instantly. The synthetic stock and light weight components, coupled with the low muzzle velocity of the design, make the compact size ideal Many, many targets were shot over the last few days and I can't discern any reportable difference in offhand accuracy. It's far handier than it's full-sized brother.
The scope attachment is the only other glaring problem with the gun. The plastic dovetail is designed for an aperture sight and makes scope mounting a challenge. Adding a 5" or 6" length of picitinny rail to supplement the short, soft plastic dovetail would be a rather easy solution. So, I guess that's in the project que.
More in a few days.