nipple threads, how to id?

[troy_mclure]

how do you id the threads on the nipple? i have a gun that the nipple is a rifle nipple, i need a shorter pistol nipple. but i dont know what threading i need.

[docone31]

You go by who made the rifle. The model, maker. That will make it able to find out which nipple it takes. Most nipple makers list who takes what.
It is fairly easy.

[Rio Grande]

First I mic the OD. Then I determine the pitch, using the optical comparator. Then I find the pitch dia. by measuring over 3 wires.
Then, using the tables in Machinery's Handbook and/or the GageMaker thread program in the computer I can find whether standard or metric (although sometimes for a given thread they are quite similar) and the actual thread 'size'.

For many threads we have thread gages, and that's the best, functional way to verify. But for metric threads we don't have many gages, so we often use the above method.

Of course I have an advantage since I work in a machine shop. We often reject items for being .0002 or .0003" out of tolerance, and our measuring capability approaches .00005" (50 millionths). But many shops can do better than that.

I know I'm being a smart'alec', but you should see what we can do with diameters, steel and lead hardnesses, etc.

With limited equipment I would say a pair of digital calipers measuring od and threads per inch (distance between crests of threads, using the old reliable 'eyeball' method - and metric conversion would be helpful here) would get you a very good estimate, given the thread specs in Machinery's Handbook or similar (maybe available somewhere on the 'net?).

If the method docone31 suggested doesn't work for you...and I had the screw I could tell you, but you probably wouldn't want to go to the trouble of mailing, etc.

[mooman76]

If we knew what "gun" you were talking about, we might be able to help easier. If you go to some of the BP sites that sell the parts, they usually list what gun they are for.

[troy_mclure]

its a navyarms seven seas derringer.

[Maven]

Troy, Or you can call Ethan at Track of the Wolf.

[troy_mclure]

i just filed the nipple down so it accepts my caps, and fits the gun better. i think it was just a bad sized nipple as it was longer and fatter than my other rifle nipples.

its good to go now.