[Blastattack]

Originally Posted by Rick W.

I had not thought about that kind of tool before. No grinding facilites here, so was out of reach locally. It certainly will be interesting how that aspect turns out. Once you have the tooling, the cut is easy huh?......... :-) Yeah, nothing like suitable tooling for the dedicated purpose.

I figure it should work well. There are other manufacturers that make a tool with similar specs. The blance you have to find is what kind of cut do you want to make? A perfectly ground tool will cut in one pass (with multiple depth cuts, of course), though a smaller tool will allow you to hog out the middle, and do some very light finishing passes, decreasing wear and the stresses induced on such a small tool. Microcut USA makes a tool with a .0458" pilot (1.19mm) and a shank of 1/4" (6.35mm), which could be easily ground to cut on each side of the groove. The tool is a little weaker, but would be subject to fewer stresses.

Originally Posted by Rick W.

I use 30 caliber rifle barrel take off's for my Luger barrels, the 1 in 10 works fine with the Luger 30's, abeit with the 308 spec which is a bit tighter than the original Lugers that folks talked about being around 310-312. Lots of new light bullets around now in the 308/309 size, but kinda proud of them, but at least they are there.

I figured 1-10 should work well. My Google research yielded a number of different twists for the .30 luger: 1-10, 1-11, and as fast as 1-8 and 1-9. I should have copied SAAMI and Wikipedia specs and gone with 1-11, but i doubt it will make much of a difference in the end. As to .308 grooves, it seems a fair number of bullets are available in .308, and squeezing a factory bullet down from .3095 won't hurt anything. Afterall P.O. Ackley shot a .35 Whelen through a .30 caliber barrel without any issues, so I don't see a thou and a half causing me any trouble.

Originally Posted by Rick W.

Hope you will show the project when the right time comes. Projects of this type are always interesting.

I will! Once I get some more of the components and tooling required I'll take an ensemble photo, and update it with progress. So far I have the prints and a barrel blank. Tomorrow i should be able to pick up my BSW threading inserts and get some more tooling ordered. Maybe my supplier will also have a reasonably priced 10mm endmill... we shall see.