Odd BBLs From Numrich

[Olle]

Originally Posted by sheepherder

Brownell's sells a curved lathe tool bit that isn't too bad for a curved tube end. I have 30º/45º/60º 'chamfering cutters' [countersinks] that I use to break the sharp bore edge and blend in the lands & grooves. (I also have tried them for cutting feed ramps; they work pretty well for that too). I'm pretty slack on 'rounding off' the end of thin barrels. The flat squared-off end looks pretty nice to me.

Edit: I just realized which barrel this is. Since it has a threaded-on front sight base, it's not rounded at all. I left it 'squared' and just broke the sharp bore edges with a 45º chamfering tool.

I looked at Brownell's cutter, and the complex grinding explains why I haven't been able to make one... I haven't had much luck with countersinks of any kind, they just shatter at any RPM. My only salvation is a crowning tool set (also from Brownells), but I would like to come up with something that works in the lathe... I hate to buy tools I can make, so I might try and grind a short miniature boring bar before I cave in and order the cutter.

[sheepherder]

Originally Posted by Olle

I haven't had much luck with countersinks of any kind, they just shatter at any RPM.

I run at low RPM (like 160rpm I think) and use 5 or 6 flute 'chamfering cutters' from Travers. I have never had a chamfering cutter/countersink shatter. (You can't use woodworking countersinks). I turn the barrel in the lathe chuck and use a Jacob's chuck in my tailstock to feed the 'chamfering cutter' in. I eyeball it until the groove is cut to the bottom.

I've seen multi-angle crowns, rebated crowns, and odd angle crowns but really, is all that necessary??? I'm a simple person, my tools are simple, my work is as simple as I can make it.

[sheepherder]

An unexpected occurrence...

The 'winner' of the auction for the 8" Numrich barrel offered the barrel to me, and of course I accepted.

Now I'm somewhat at a loss...It's 30 cal, and I don't have a 30 cal artillery Luger, so I could go that way (I have a cut-down Luger artillery barrel with intact rear sight base that I could bore out and sleeve over the Numrich barrel)...Or I could use it to make a 30 cal Walther 'artillery P-38'...

I bought two 30 cal 'pulls' to use for 30 cal barrel replacements [Win M-70 & Rem M700] so I don't really need to use it for a 'blank'...

I already have a 13" 30 cal barrel ready to turn into a Luger 'Buntline', so I don't need it for that...

I've kind of run out of WW II pistols to turn into artillery whatevers...

How best to make use of this windfall???...

[sheepherder]

Continuing with the 6" 30 cal barrel...To the rear!

This will hopefully be the last 2-cut extractor notch I do; I'm going to try grinding an oversize Woodruff keyway cutter to Luger dimensions...

This is the second time I've cut the feed ramp this way, and I'm delighted at how nice it comes out...

[sheepherder]

While I had all the tools, cutters, fixtures, and notes out and still firmly fixed in my mind, I did a 2nd 6 inch 30 cal Luger barrel extractor notch and feed ramp...

I have a 3rd 6 inch barrel in 9mm that needs notching & ramping, but enough of the pics...

I'm starting to get the hang of it now...