.177 Diana Chaser rifle barrel on my Plinkster. VERY backyard friendly. Really sounds about like a staple gun. I move the moderator back and forth between this and the Chaser, which currently has the pistol barrel and shoulder stock. Really handy little carbine. Love these Snow Peak guns. Can't wait for parts to become available.
Not sure about the thread protector, but I guess so. I made my own LDC for my .22 pistol with a M10-1.00 fine pitch nut, some 3/4" copper tubing, and a few hair curlers. Both of my Chasers (.177 rifle kit and .22 pistol) have great triggers as they came. The Plinkster and Dragonfly both have Steve-in-NC's aftermarket two-stage drop-ins. All 3 of my CO2 SPAs have the AoA FFHDD, (also Steve's design,) which greatly improves gas mileage.
there is the grub screw you can't get to without the grip frame off and it is a m3 and only 3mm long I replaced with a 6mm one with a 2mm ball bearing epoxied on and add new 2.6mm pins and .25mm shims and drilled the sear for a trigger stop using m3 by 6mm long grub screw and used teflon tape on all the screws
now it is better