Odd BBLs From Numrich

[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.