bonehead barrel threading question

[hammerhead_77]

OK, I know this will get a snicker from all you machinist pros...

I want to thread a barrel to 14-1 LH. The current barrel OD is 14.06mm. Can I just loosen up a split die and use that to cut it down, or do I need to turn the barrel down to 14.00mm?

[bigcalidave]

It's a good question. I've been trying to find the basics for threading a barrel too. So far, I've found the following tools,

http://www.dinzagarms.com/tools/mcp.html

$100 for a cutter (and pilot and adapter) that rides in the bore and cuts the barrel down to the proper size.

http://www.dinzagarms.com/tools/tkp.html

$45 for the die and centering adapter for cutting the threads.

http://www.dinzagarms.com/tools/crownp.html

$70 for a crowning tool.

Pros, would those tools be good for cutting and threading a barrel? Could I do my 10/22 pistol barrels with them on a drill press?

Is there another source for similar tools? I'm not sure I want to wait a month to get those!

Thanks!

[kcstott]

.06 mm is not enough to worry about. Just loosen up the die and go to town. Problem is keeping the die straight.

[hammerhead_77]

Thanks much for this and your reply to my other thread...

I am going to get a die starter to help get things started straight and hope for the best. I've cut lots of threads before, just not on a rifle.

https://www.cncwarrior.com/shop/22768-12-28-die-starter-for-7-62-cal/

Since this is not a precision rifle, I'm guessing I can be up to 10-15 thousands out of center without noticeable impact...hopefully the starter guide will be sufficient.

Again, thanks.

[JagerDog]

You don't loosen the die to accommodate oversized stock. Loosening the die increases the pitch diameter with the goal of getting a higher tolerance fit to whatever you are screwing it to.

Male threads should be slightly under nominal while female threads should be slightly over nominal. 0.06mm is ~0.002". Pretty minimal. I'd probably run a standard die then file down the crests of the thread a bit.

Be warned though, the steel alloys used in firearms may not cut cleanly with a die.

[NotEnoughGuns]

.06 mm is not enough to worry about. Just loosen up the die and go to town. Problem is keeping the die straight.

This.

Die nuts are rude and crude. So will be your results.

[Jeepers]

just my 2 pennies but the correct way to do it is to pull the barrel and thread it on a lathe .....

[kcstott]

Yeah but that wasn't the question.
And yes you can loosen a die to get it to accommodate larger stock. You just need to run the die over the threads again once you tighten it up.

But yes the proper way to thread a barrel is to chuck it up in a lathe and do it right.

$75 shipped is my price

[Dan FS71]

Unless your planning on putting a can on it or a 6 inch extension, using a lathe is just extra time & hassle for minimal gain. A die starter is plenty.

[hammerhead_77]

I decided to reach down, grab a pair, and do it myself. I'll post a thread with pics. So far, it is not very scary.