Hand Tapping Machine

[rossbotics]

Hi Jamman
Looks good man, your doing a good job from what I can see, I'm not up to par on rifling a barrel, I have made allot of gun parts though, and have made some custom rifles from scratch, but I always bought a chambered and rifled barrel, I would though do the outside contouring of the barrel,threading etc. I'm afraid I wouldn't be to much help to you on your project, but do keep me posted on your progress, I would love to see your work when you finally get it all together,

Good Luck
Doug

[Jamman]

thanks bud

[Frank S]

HI Rossbotics; I really like your taping fixture A chuck removed from a "T" handle tap wrench might serve better than a 3 jaw Jacobs I'm not thinking of a Starrett 93c but a Vermont American 21916 T-Handle might do well. Or if you have an index fixture you could hex grind the tap shanks. My luck with trying to hold taps in my drill press always slip in the chuck no matter how tight I try and tighten them.
Jamman I don't want to hijack this thread but a .22 rifle has a bore of .22/100 nominal 5/16" is .312" I trust that you are going to sleeve this with a tube that will press fit in the 5/16" bore then ream and hone before attempting to rifle the bore. Do you know what grain bullet you plan to fire through it? because this will also determine the amount of twist you should target for.
the twist in the riflings are all over the board ranging from a 1 in 14 for 48 to 50 grain to 1 in 7 for a 60 or higher with the 1 in 9 or 10 being quite popular in small bores
Spiral end mills the diameter you would need to regrind into a button would need to be at least a 6 fluted mill an odd numbered flute would be better for centering in the bore but I've never seen a 7 fluted end mill that small which would also have a very tight spiral of around 1 in 1.5 to 1 in 2 far too tight to be reground into a button. but if very careful attention was paid to the regrind of a .250" end mill there might be enough material in the cross section of the fluted to yield the features of the button when the grinding was completed.
I suppose you could do this with a 2 fluted mill but it would be very difficult if not nearly impossible to hold it perfectly centered as it finished forming the groves additionally you would still need a fixture such as one I started designing for my Clarkston tool grinder which I no longer have
this 5 axis tooling fixture that I hope to one day build and perfect would probably be what would be needed to make a proper button

My apologies for the hijack