Underhammer Project

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Underhammer Project

Postby cachelapoudre » Thu Apr 30, 2015 5:04 pm

Since I discovered this site I've learned much about the finer points of building a rifle or pistol and "gotchas" of kits. I came across an unfinished Numrich "Hopkins-Allen" Underhammer Heritage rifle kit and picked it up in a heart beat. I was a kit that probably did not pass inspection or was pushed through for sale.

The receiver was not drilled or tapped for any sort of attachment to the barrel. Nonetheless I figured out what was needed and now I finally have an Underhammer rilfle in .45 calibre.


Putting the kit together was not a problem, though I had to figure out how to secure the breech plug to the receiver. Three holes drilled and tapped did the trick.

My biggest dilemma was the finish. I've completed a couple of other kit guns and posted the results but this time I wanted a dark black finish on the metal. Captchee's previous comments helped me get that deep black look I wanted.

Thanks to Captchee with his bleach and boiling water approach. It worked well though the dog and cat did not want to come in to the garage most of the day.

I plan on sighting in the rifle tomorrow.
Last edited by cachelapoudre on Fri May 01, 2015 8:49 am, edited 1 time in total.
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Re: Underhammer Project

Postby McClura » Thu Apr 30, 2015 10:46 pm

Very nice---I'm jealous. Had one of those with a Green Mountain 40 Cal barrel and one of the pistols in 36 Cal. shot them for years. It should be a shooter. If you have them, a .445 round ball and .010 patch of light denim or pillow ticking type material and about 50 grn of 3F should get it cooking.
Everyone of the underhammer rifles and pistols H&P made had shallow riflings. They like a tight ball/patch combination. If you have the .440 roundballs you can probably go .015 patch. I always would start mine after laying the patch on the muzzle and ball on the patch, with a short starter and a rubber mallet.
The .45 cal will shoot real good out to 50yd with the 50 grn of 3f. I have a .45 now and when I loan it for hunting deer I give them speed loaders loaded with 60grn of 3F and the Hornady Great Plains bullet but I'm not sure you can find them anymore. Some sabots might work or the Lee Real Bullet.
Good luck- keep us informed how it shoots.
I ended up putting a set of Redfield International peep sights on mine and shot it for Bench and X-stick matches. Very accurate in 40 with the green mountain barrel.
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Re: Underhammer Project

Postby cachelapoudre » Fri May 01, 2015 8:53 am

Thanks for the loading information McClura.

I will start out with 45 gr. of 3f with a .440 ball and .015 patch (that's all I have on hand at the moment. My goal is to use the rifle for our 100 yard w/sticks events at our local rendezvous along with my .45 cal pistol.

Next on the list is finding a .45 calibre underhammer pistol.

Will post shooting results later.
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