A "Traditional" Underhammer Pistol

For some of us, few things can compare with the satisfaction we derive from shooting muzzleloading arms. For some fewer of us there is nothing like the thrill of shooting a firearm that we designed and built ourselves - a rifle, pistol, or shotgun that embodies our best ideas of design and ergonomics. It actually is the manifestation of our imagination and in that respect it becomes a very personal item indeed - much more so than any off-the-shelf  "ready-made."

It pleases me so much to learn of our many readers who are taking up the challenge and building their own underhammers. While it seems that most are too bashful to share their work, I thank those who have sent copy and photos describing their work to help inspire even more of you underhammer aficionados to give it a try. I would like to add here that I hope that you builders are identifying your work. There is so much confusion today regarding the makers of obscure underhammer designs of old because the makers did not consider marking their work for one reason or another. Who knows, maybe your design will someday be viewed as significant in modern underhammer history. At least your great grand kids might bask in the glory - if you had the foresight to mark your work.

Greg Sefton is one of our readers who, like a growing number of you, decided he wanted an underhammer done his way. After a bit of research, he jumped in with both feet and built the pistol you see below. What’s more, his prize is now winning him prizes as he competes with it in muzzleloading competition. But I’ll let him tell his story…

One more thing, remember that clicking on any of the photos will enlarge them for detailed viewing. Click the Back button at the top left corner of your screen to return to the text.

A Traditional Underhammer Pistol

by

Greg Sefton

As a sometimes critic of underhammers, I never thought I'd be building one. My main objection to most underhammers was their appearance. As a muzzleloader fan for over 50 years, I like a muzzleloader with a stock and fore-end as one single piece. The one underhammer experience I had (it was an H&A) was negative. The cap flash sprayed my forearm and the cap kept falling off the nipple. There were a couple of other small things among them being unable to easily remove the barrel for cleaning or to interchange barrels.

Needing a "traditional" style percussion pistol for competition, I decided to try an underhammer design, but made some changes to overcome those objectionable aspects I mentioned. In the course of my research I picked up an interesting book, "The Pictorial History of the Underhammer Gun" by Herschel C. Logan, and got a few ideas from there. Using some of the parts from a Billinghurst action that I got from Muzzleloader Builders Supply (http://muzzleloaderbuilderssupply.com ) I drew up plans for a hooked-breech target pistol and proceeded to build it. 

Bringing the components together.

I made a conventional standing breech with a tang and made it to accept a hooked breech plug. I also welded a lug on the bottom of the breech so that the front of the underhammer action/trigger plate could be attached to the receiver with a machine screw. The barrel was made by Ed Rayl and is 36 caliber and 13/16” across the flats. The breech plug I made of 416 stainless steel and fitted it to the standing breech and the barrel. The barrel removes in seconds for cleaning with no tools. It uses a conventional cross key and staple in the bottom of the barrel to secure it in the stock. Sights are fixed and quite simple in order to comply with NMLRA (National Muzzle Loading Rifle Association) rules.

Sights are a simple affair.

The stock is made from Eucalyptus wood that I cut on my sawmill a few years back, so it was well seasoned. That's the natural color and most of it is figured like that. The grip is capped with a brass plate rounded slightly and polished partly to protect the butt and add some weight for good balance. 

MBS Billinghurst hammer and trigger.

As I mentioned, I used the trigger and hammer of the Billinghurst action from MBS. The hammer is lightened somewhat to reduce movement. I also drilled and tapped the trigger to accept an adjustment screw for sear engagement and trigger stop. You could also create an adjustment for a weight of pull, but this one breaks nicely at 12 oz and I didn't need to do any adjusting. I also added a filler wedge behind the trigger guard to provide a consistent grip and better feel in the hand.

To eliminate that nasty cap spitting I created a nipple pocket by using a short section of brass tubing that I epoxied into the nipple well in the stock. This also protects the wood from cap spray. Now the nose of the hammer and the nipple are completely enclosed and no more spitting.

A simple nipple pocket stops nasty cap spitting.

This pistol is exceptionally accurate and easy to shoot. I've won some matches with it and have about 400 rounds through it now without a single misfire or malfunction of any type. I made up two mainsprings for it, a light one and a heavier one to compare the locktime. They seem about the same so I'm using the heavier one. I load 000 Hornady buckshot (.350" diameter) wrapped in an .018” thick ticking patch with a load of 15 grains of Swiss fffg powder.

Eventually I’ll brown the metal and install a pewter fore-end cap to finish it off. I'll also be making up a couple of extra barrels for it in .32 and .45 caliber.

I'm not a total underhammer convert yet, but I'm coming along. A clay bird 12 gauge underhammer shotgun is under construction on the workbench :o)

~Greg Sefton

All photos copyrighted by Greg Sefton

Thanks, Greg, for sharing your project with us.

So, if you’re thinking of building an underhammer firearm, come on in – the water’s fine.

NOTE: Some of you may notice that the lockwork of the MBS Billinghurst action does not provide a safety notch. If you are planning to use this action, I would like to recommend that you scroll down the page and take a look at our earlier post, The Billinghurst Underhammer Rides Again! With close observation you can see how a half-cock notch was added to the hammer of the Billinghurst. You can also check the Older Posts for my article, Underhammer safety. Low-tech to the rescue, which will provide a simple means of making these earlier underhammer designs much safer at the range or field.



Cheers!

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