Odd BBLs From Numrich

[Edward Tinker]

Rich, I don't understand how you can be sure of the threading. This is where my stupidity comes out I know. Surely you don't thread these by hand with a lathe?

Second question
If you have an old barrel with messed up threads, are there such things as a thread fixer? Like the type I have for small threads that are screwed up?

Ed

[John Sabato]

Originally Posted by Edward Tinker

Rich, I don't understand how you can be sure of the threading. This is where my stupidity comes out I know. Surely you don't thread these by hand with a lathe?

Second question
If you have an old barrel with messed up threads, are there such things as a thread fixer? Like the type I have for small threads that are screwed up?

Ed

Hi Ed
Threading them on his lathe by hand is exactly what he is doing. And it is the only way to get the threads concentric with the bore. It isn't rocket surgery . All it takes is the tools and appropriate instruction and practice of which he obviously has both. There are even videos on YouTube where you can see how simple (but tedious) a process it is. I am sure he could create a thread chaser (die) if he needs one but I am pretty sure they aren't available commercially for Luger barrel threads.

[sheepherder]

Yes, as John noted, I cut the threads on a lathe, feeding the 60º thread cutting tool bit in one thousandth at a time, until I get close then I switch to 1/2 thousandth. My tool post is set up at 60º also; that is what I feed in by hand (in thousandths). My table feed is set to the thread pitch, and chuck/spindle speed is lowest I can go.

I don't know if anyone makes a Luger barrel thread die or tap. In any event, trying to thread a barrel with a die wouldn't get it concentric with the bore, as John commented.

I have pics of the threading process before & after, but I can't take pics while threading. I need both hands free to throw the appropriate levers to stop the feed and retract the cutting bit at the end of the cut.

"Thread fixer"...Like a thread file? Yes, I have a 20tpi thread file, like for taking dents out of a thread if you were to drop it or something. But if it's serious, like a Luger barrel I had that was soldered to take up gap, then I turn it in the lathe. And/or 'pick up the thread' and re-cut it.

[sheepherder]

Originally Posted by Edward Tinker

Rich, I don't understand how you can be sure of the threading. This is where my stupidity comes out I know. Surely you don't thread these by hand with a lathe?

I do thread these on a lathe...

Here's the receiver end of the barrel being threaded, ~.704" x 20 tpi...

I've also re-tapered the 'fat' taper...

Next will be threading the muzzle end...I'm still deciding whether to make a threaded front sight base + band or saw off an old Luger front sight base/band and thread it...

[sheepherder]

I thinned the big end of the taper down about .085" off the OD; left the front sight band end alone. It looks a bit better. Here's a comparison of before & after -

[sheepherder]

A member pointed out to me that a 4" Luger front sight band + base would be too short for a 6" 'Navy' style barrel...So I guess I'll be making one from scratch...

I looked at Ed Tinker's albums, and Ed has a Navy pictured -



Unfortunately, Ed sold it. I can try to extrapolate the front sight base height from the pic...But if anyone has a Navy (or a repro) they could measure, it would make it easier!

Thank You!

In the meantime, I'm working on the front sight base/band blank...

[sheepherder]

Continuing to mill the screw-on front sight band + base...