Jimbo's Underhammer

[jimbo15563]

I have decided to have an Underhammer built and I thought I might share details, costs, and pictures of the project. I will do this in a series of posts in hopes that I might help someone interested in a similar project, as well as to solicit advice from more experienced members of this forum.

Background:

I live in PA, which has 3 deer seasons. 1. An October Antlerless Muzzleloader Season which allows all types of muzzleloaders, sights, and projectiles as long as they are .45 caliber and above. 2. A Regular gun season the 2 weeks after Thanksgiving 3. A primitive season the 3 weeks following Christmas which allows only open-sight flintlocks shooting any type or projectile.
I got in to Black Powder in order to extend my time in the woods and to provide family and friends with my Jalapeno-Cheese Deer Bologna. I've shot 6 deer in the last 3 years - 3 with a TC Renegade Flinter, 1 with a TC Omega, and 2 with an old Marlin 30-30. I have found much enjoyment in Black Powder and have begun shooting just for the fun of it. I'm not happy with the Omega, and 209 primer ignition in general, and plan to replace it with an equally efficient, but more traditional underhammer rifle. I have no gunsmithing abilities and will pay to have the first one built. I'd like to learn enough to do one on my own someday.

The Concept:

I have heard nothing but good about the underhammer's simplicity (only 2 moving parts), it's instant ignition, and it's potential for accuracy. I fell in love with the sleek lines and envision mine to look something like this:

It will be a work of art in the modern sense, more like and Eames chair than a Chippendale. I will sacrifice PC for functionality. I plan to have interchangeable barrels and add them 1 at a time as my budget permits.

The Builders:

Bruce from Blue Grouse has been my adviser. We've spent hours on the phone planning this project. He has been very patient and helpful. I plan to buy my parts from him, as well as some of his cast conicals to shoot out of it. If you're interested in underhammers, his website is: www.underhammers.com :applause:

Dave Stotler is a local gunsmith and personal friend. 30 years ago he was the manager of a Skeet and Trap Field where I got a part-time job as a teenager. I shot so much skeet that I owed him money on payday. Dave specializes in 1000-yard centerfires for competition at Camp Perry. He creates beautiful stocks in Spalted and Curly Maple. Since his guns have started winning he is now getting orders from all over the US. :applause:

In order to get this rifle completed in time for October deer season, we are starting now. More posts will follow. Please feel free to offer advise and comments.

Jimbo

 

[BillinOregon]

Jimbo: Please keep up the posts. I'm also looking into building an underhammer big bore -- probably a .72 -- for large game and just because I like big bores. I have an e-mail in to Bruce right now.

 

[BS]

Keep us posted on your progress......!

 

[jimbo15563]

Choosing the Action 1

After a meeting with Dave, we discussed finishes for the stock and action. I decided on a case-hardened action. I called Bruce after looking at his website, which lists 3 types of actions available:

1. The traditional H & A cast iron. The breech plug is attached with Allen Bolts, making it good for interchangeable barrels. The Breech Plug is threaded 5/8 x 18 National Fine. The cost is $130 plus shipping.

Custom breech plugs are available at additional cost.

2. A milled 4140 threaded breech action, which he doesn't recommend for interchangeable barrels, the cost around $200.

3. A stainless threaded breech action,costing over $200.

The other difference between these actions is that the trigger tuning on the 4140 and stainless is done with an allen wrench. The cast iron is tuned by filing.

I initially wanted 4140 because of the case-hardening, but he's having more made and and they aren't availble right now. Because of time constraints and the interchangeable barrel feature, I told him I would send a check out for the traditional lock.

NOW I'M HAVING SECOND THOUGTS

I really have my heart set on the case-hardened look.

My Marlin 30-30 is 70 years old and is still pretty after having taken a lot of punishment. I don't know much about the properties of cast-iron. Can it be polished and case-hardened, or should I wait on the 4140? I'm going to put in another call to Bruce before I order.

Jimbo

 

[Mr Nick]

On the picture of the side lock, is that rear sight on backwards? It looks like a older militaty rear sight but reversed.

 

[jimbo15563]

Finishing the Stock 1

Dave and I discussed the stock earlier this week. I want the rifle to look like the picture in the first post. He has a beautiful curly maple blank with enough wood for the long forend. I saw a picture of a repro flinter that was finished in a dark whiskey brown. It was described as "Lancaster Maple". If I can find that picture again, I'll post it. I want it to have nice clean lines, with little decoration except maybe a silver cap and patchbox. Dave quoted me a price of around $300 without the box.

Thinking ahead, I need to find a first barrel configuration which would be compatible with future barrels of different calibers such as a .36 for squirrel and a .62 smoothbore fouling piece/turkey gun. I want to use the same forend for all of them. I'll deal with barrels in another post.

Another consideration for the stock, will be inletting for the ramrod thimbles. I want to consider how to make the finish hard enough to withstand hunting conditions. I don't want this to be a "wall gun". :hmm:

Jimbo

 

[[email protected]]

Howdy neighbor.....Jest wondering if ya are familiar with the "MOWREY" rifles.??? They are simple in design also.
Quite pretty If I say so myself....
Dont get me wrong......I love underhammers also.

*** WV SCROUNGER ***

 

Nope - that's correct for a British firearm of circa 1860 vintage. :m2c:

 

[jimbo15563]

The Mowrey's are Very Nice - I saw one in an online auction going for around $300, so the price is quite reasonable. The auction had some good pics:

The link to the auction is:

Mowrey Percussion Rifle 50cal

The same simplicity of design that attracted me to the underhammer.

Jimbo

 

[faw3]

ive had 2 of the 50s mows from deercreek love them till i wore em out can get only 1 66 twist he cuts them and isnt takeing orders as of 2wks ago.i would like to get a few a@h old underhamers for a son dad thing to do shooters or parts rifles must of been a zillion of these made since 62 or63 at at 65 bucks poiwder caps and balls any one help me out with this or even a numrich arms buggy rifle and if you cant tell this is the first time ive touched a pc.

 

[jimbo15563]

Choosing the Action 2

I talked to Dave again, and he says the cast-iron action will polish and case-harden just fine. As to it's durability, Bruce has used them in 4-bores with no problems. I'll be placing the order Monday. The barrel I've chosen has a different thread than the H&A breech plug, so I will add a custom breech plug to the order.

Cost: Action $125 Breech Plug $25 Shipping $8
Total $158

Jimbo

 

[Protrucker]

What length barrell are you getting? I ordered a .36 buggy(26" barrell) rifle back in December & haven't gotten it yet. Bruce has informed me that he is still waiting for the 26" barrells to be manufactured.

 

[CrackStock]

Has he come around to stocking .40 cal barrels yet? He only keeps a few calibers in the base pricing and I was wanting a .40 in the boot pistol.

CS

 

[jimbo15563]

I looked at the Numrich (E-Gunparts) site and they seem to be out of most of the H&A underhammer parts. This is his supplier.

Jimbo

 

[jimbo15563]

Choosing the Barrel 1

My idea for this rifle is to buy additional barrels in the future. I want the first barrel to have exterior dimensions in which a large number of additional calibers are available so I can use the long forend on all of them.

For a while, I toyed with the idea of getting a Hexagonal Rifled Whitworth similar to the ones used by Confederate snipers during the Cival War. See this thread in the Percussion Section: Looooooooooong range gun

I located one but unfortunately the price was nearly $400 unfinished. That price, plus finishing costs are more than my budget allows. I may revisit this idea at a later date.

I looked at other custom options such as Orion or Ed Rayl, but again they need finished and the barrel plus gunsmithing costs would easily exceed $300.

I have finally decided on Green Mountain IBS interchangeable barrels. For $189 (blued)to $264 (stainless), you get the finished barrel complete with sights, ramrod thimbles and ramrod. Track of the Wolf has slightly lower prices, but they don't offer the stainless.

For the underhammer, I will order a percussion barrel. All that's needed to adapt it to the H&A action is to twist out the snail (patent breech), screw in the breech plug, and drill and tap the nipple hole. The Green Mountains have different threading than the H&A breechplug, so I ordered a custom one with compatible threads for $25 from Blue Grouse. It will ship along with my action.

I haven't decided exactly which barrel to order. It will be a 1" hexagonal because that configuration has the greatest number of calibers/twists available for future additions. Dave thinks the blue would look better with the case-hardened action, but I'm leaning towards stainless (only available in .45 or .50) because of the ease of cleanup.

I have until next payday to decide and to order the barrel. That will give Dave time to case-harden the action. He is a very busy guy.

Jimbo

 

[BillinOregon]

I'm liking your project, Jimbo. Can't wait to see how that receiver takes the color case.

 

Just some FYI for ya on the GM barrels is that the breech will need a bottoming tap in order to finish seat the plug, but you Gunsmith should'nt have a problem with that, as He will have to square up the plug to the top flat. Bill :m2c:

 

[jimbo15563]

Thanks Bill,

Hadn't thought of that!

Jimbo

 

[44-henry]

I purchased one of these actions on auction arms about a year ago, I ordered the stock with it since I was curious how it would look. I was not unhappy with the action, even the stock was pretty nice, though too plain for my tastes. I had a 1 1/8" Green River 50 caliber barrel which had been for years sitting on a shelf in my shop gathering dust, I still haven't got around to building the gun yet, I plan on restocking it with a more fancy piece of maple and modifying some hawken hardware that I have lying around to work with this gun, hoping to create something of a Hawken style underhammer.

 

[jimbo15563]

Choosing the Nipple 1

According to Bruce at Blue Grouse
Bruce's Website

a #11 cap is all that is necessary to ignite the charge. The nipple is in direct contact with the powder and fires straight up. This result is a big savings vs purchasing musket caps.

He also brought up an interesting point about fitting a nipple to a custom barrel. An off-the-shelf nipple might not be the exact length required. Too short, and it doesn't contact the powder. Too long, and it could interfere with the cleaning jag.

He referred me to Ron Blomquist at:

Blomquist Percussion Works

He said to call Ron and let him know the caliber and the outside diameter. He could make up a kit that includes 3 custom nipples, a pick, and a wrench. The nipple would fit EXACTLY and the prices seem very reasonable.

Bruce told me another thing I didn't know. When shooting for the best accuracy possible, the nipple should be picked after every shot. Apparently, the amount of spark getting to the powder can make a big change on where the projectile hits the target.

Jimbo