Continuing work on the forearm. I made this one eight inches OAL. That makes it half the length of the barrel, which looks more balanced to me.
(34) Side milling the bottom of the forearm, using a 5/8" end mill and taking ~.030" deep cuts, ~.080" wide.
(35) Side milling the tapers on each side. Taking about 1/8" taper off. I thought I'd take a couple 'action' shots, just for a change.
(36) Milling the curved end of the brass inlay bar, with a 3/16" concave radius cutter.
(37) Drilling the relief holes for the inlay screws in the forearm inlay.
(38) Switching over to a 3/4" corner rounding end mill to round the bottom of the forearm. Another 'action' shot.
(39) Brass inlay being milled down with a 3/8" end mill to match forearm bottom surface .
(40) Beveling the upper edges of the forearm.
(41) Forearm, brass inlay, and brass attaching screws are finished. Wood has two coats of BLO on it, and I was surprised/disappointed to see how dark it turned out.
Next up is to stamp or cut index marks for the barrel/receiver and front sight ramp/base and barrel. I also want to bevel the muzzle and and crown the bore slightly.
(42) Here's a comparison of the 13" barrel & 6 1/2" forearm and the 16" barrel and 8" forearm. I've seen pictures online of 16" carbines with the short 6 1/2" forearms; they look disproportionate to me. These two combinations look much more proportional IMO.
Finishing up some of the 'little things' that need doing; feed ramp, extractor notch, muzzle crown, muzzle cap bevels...
(43) Using a curved lathe tool bit from Brownell's to cut a radius on the muzzle. I've had mixed success with this, it seems to chatter a lot.
(44) Cutting a 45º bevel on the end of the muzzle cap. I also opened up the hole a bit and beveled that as well.
(45) Cutting the feed ramp with a 10mm end mill.
(46) Different fixture; cutting the extractor notch with a 3/32" Woodruff keyway cutter followed by a 3/16" Woodruff keyway cutter. Sharp edges will be rounded off with a needle file.
That should pretty much finish up machining operation for the 16" barrel and forearm. I'll be looking for a mailing tube to send it off for blueing. I haven't decided if I should get a separate toggle assembly for this upper, or just use the 13" toggle assembly. Really doesn't matter, I suppose. I can only use one at a time. If I was to get a separate toggle assembly, I would probably be tempted to build another long-barrel frame assembly to go with it...
