Help with some nipple sizes...

[Brian Boru]

Hello,

I recently purchased a Mowrey .54 cal and an H&A Underhammer .45 cal.

”¦Wanted to order a few extra nipples for each, just to have.

Brought out the calipers and thread gauge”¦

The Underhammer seems to have a ¼ -28 thread. I went onto Track’s site to see what was available. But there seems to be several different sizes. I know it’s a #11 cap, but they have listed 3/8, 5/16 and 7/16 all in the 1/4-28 size.

The Mowrey nipple seems to be a touch longer in the threads.

Where are the measurements taken from?

Does anyone have either of these rifles to help with nipple size?

Thanks to all in advance.

Brian

 

[Zonie]

If I were you, I would buy either the RST-A or the RST-S for both guns.

The underhammer nipples you refer to have extra long threads so that the end of the nipple can extend up inside the barrel to the center of the powder charge.
The length is the distance from the shoulder to the end of the threaded portion of the nipple.

While this might be nice for the target shooters who are looking for that last little bit of an advantage over the rest of the competition IMO it has one disadvantage for the normal person.
That disadvantage is that the nipple is blocking off the breech of the barrel so very light powder charges won't be compressed by the ball (which will stop on the exposed nipple threads).
It also puts the threaded area of the nipple in the way of a wiping rod/patch for those who wish to wipe the full length of the bore between shots.

Here's a old zonie story dealing with things projecting into the bore:
I had built a percussion sidelock rifle with a typical side mounted percussion drum screwed into the side of the barrel.
I took it to the range and the thing misfired. The next cap fired it alright however after shooting 16 caps to fire 10 shots, I took it home to clean it. That's when I found the problem.
I had not trimmed off the drums threads flush with the bore and it was sticking into the bore about 1/4 inch.
After trimming off the excess threads so that the threads were flush with the bore, and returning to the range, the gun fired first time, every time with just one cap per shot.
After this experiance, I don't like the idea of the nipple threads extending into the inside of the bore.

As I see it, for your underhammer, if the threaded length of the nipple is equal to or slightly less than the wall thickness of the barrel, you have the best setup.

zonie

 

[Slamfire]

My Numrich underhammer has 1/4-32 threads and a square shank. Somebody might have changed yours but it its an original barrel, I'd bet that's what it is. :v

 

[Brian Boru]

Thanks for the information. I'll put an order in for the nipples you've recommended.

Brian

 

[Flint62Smoothie]

FWIW Thunder Ridge has a chart up on their website showing what nipple fit which muzzleloader.

I agree with Zonie, my H&A underhammer was more reliable when the nipple did not intrude into the bore, as I too preferred being able to swab the full length without pulling the nipple.