Jimbo's Underhammer

[gmww]

Funny you mention the stock being thin. The ones from Deer Creek were just 2x2' pieces of wood. Lots of meat on them. However, the one's I got from Numrich Arms are thin like you say. I'll learn soon enough how it holds up. The Deer Creek ones are doing great. :hatsoff:

 

[faw3]

Most of mine dont have a fore stock on them, I like it just that way, but since I dont carry a rod on it I have one I put a small nut on bottom of barrel then ran a small bolt thru bottom of fore arm. FRED :hatsoff:

 

[jimbo15563]

I'm ordering all the little parts we need for the rifle and am now thinking about ramrod thimbles. I have been looking at:

Muzzleloader Builders Supply Thimbles

I think I need 3 - one to fit in the forend and 2 more up the barrel. I'm going with 7/16" so I can use the same ramrod for the .54 and .62. Not knowing much about the terminology, could somebody please answer some dumb questions?

1. What do they mean by upper entry and lower entry?

2. Which sets are suitable for this project? I'm thinkng that the front 2 should be soldered to the barrel and the rear one incorporated into the forend.

3. Does anybody have and alternative suggestion?

I'd like to buy the parts ready-made, rather than tie up Dave's time machining them.

Thanks,
Jimbo

 

[gmww]

Tie up John Taylors time machining them instead. He made them work for me.

 

[John Taylor]

The ones pictured at muzzle loading supply are for mounting on wood. The upper would be the 2 or 3 toward the muzzle. the lower would be where the ramrod inters the wood. If you go to parts number 14040, this looks closer to what you want for an underhammer where it will be mounted to the barrel or a rib.They can be held on with solder or screw. I like a flat area for soldering, the more area the stronger it will hold. Must UHs don't have a thimble where it inter the wood and depending on how you mount the forearm you may not need one under the wood so 2 thimbles and the forearm will work for holding your ramrod. Some people like a spring to help hold the ramrod in under recoil. I have mad thimbles in the past with a lug for a sling swivle.

This is what I made for a customer a while back, dovetails to the barrel. one has a screw hole for holding the forearm

 

[jimbo15563]

John,

What you showed in the picture is perfect! I like the dovetail idea better than solder. It also solves the attachment of the forearm issue.

Would you possibly have time to make me up 2 sets for 7/16 ramrod? If so, please let me know how much and your address and I'll get you a check in the mail the next day.

Thanks,
Jimbo

email: [email protected]

P.S. I also sent this to you as a private topic.

 

[jimbo15563]

I sent the following request to Ron Blomquist at:

Blomquist Percussion Works

Mr. Blomquist,

I was referred to you by Bruce at Blue Grouse Black Powder. I'm having a custom underhammer built from an H&A action. I have two barrels, both 1" octagon. One is a .54 amd the other is a .62. The action is octagon, measuring 1.200 across the flats.

I saw your nipple kits with 2 nipples, pick and wrench. What I am interested in is a kit containing 2 No. 11 nipples, 2 musket cap nipples (with same threads), pick, and wrench. I would like to have 2 kits, one with the proper nipple depth for the .54, and one for the .62, both nipples of the proper height for the H&A underhammer.

I can either order from your existing stock, or custom-made, based on your recommendation.

I'll post the answer when I get it.

Jimbo

 

[jimbo15563]

Since this rifle will be primarily used for hunting deer, I'm ordering this:

Safari Sling from Cabelas

For an old fat guy, I do a lot of walking. Towards the end of the day, any iron I'm carrying gets pretty heavy. This should help.

Jimbo

 

[John Taylor]

Would you like a thimble with a lug for a detachable sling swivle? It's been a few years sence I have made one this way but I think I remember how it's done.

 

[jimbo15563]

I got my second barrel from Ed Rayl - the 1:104 Twist .62. Dave's finishing up another project this week and I'm next on the list. Most of the parts have been ordered. I will post pictures as it progresses.

Jimbo

 

[faw3]

Hey Jimbo thanks for starting yours way back when,it got me started on makeing the H+A uhs. John Taylor sent me a great barrel, I guess its about the same as yours but round, Ive got 3 more 62s that are oct, smooth and rifled, I had to wait about a month for mine and it drove me :youcrazy: Now Im covered up in underhammer stuff and barrels and haveing more made, you really started something. Fred :hatsoff: if ya missed mine its on perc "poor mans zep"

 

[jimbo15563]

My underhammer was put on hold due to some financial issues. We are now proceeding with the project. Dave has cut the breech plug, mounted the .62 barrel to the action, and attached the rough buttstock. Tuesday, we will mount the sights and take the measurements for the stock. We are going to use a modern recoil pad. Zephyr's have ported barrels on their 20-bores, but I have concerns about shooting a ported barrel while hunting with no hearing protection.

We are using these sights:

Ashley Ghost Aperture Sight Set

I purchased these last year and temporarily mounted them on my Renegade Flintlock.

I had good results off the bench and shot several deer in heavy cover. The target acquistion was easy, and the shots hit right where I aimed.

 

[BS]

Jimbo,

Rayl is building me two new barrels for my UHs, a .675 and a .729 cals. 1.125 x 1 x32 long. I plan on lapping them and trimming them shorter. :grin:

You have got to love them big hole peep sights :grin: They look Great! :thumbsup:

No-BS

 

[paulvallandigham]

Unless the ported barrel is really short( like 20 inches) it should be no problem. If its more than 30 inches long, the blast will be far enough forward that you won't be bothered. Remember that the report of Black Powder Shotguns has more boom than modern guns, which sound like " whack " instead. But, its that higher pitched " whack" which can hurt the ears. With a 20 ga. barrel you are going to be using loads that are less than 3 drams of powder. They just don't make enough noise to be worried about, particularly when out hunting when only a few shots are fired each day.

I have custom made earplugs, that I had made by the Beltone people( who make hearing aids). When I go hunting using modern guns, I put my plug in my off ear- the ear that is going to be turned towards the muzzle of the gun, and will received the largest amount of the blast sound wave. The other ear, on my dominant side, I leave open so that I can hear birds rise, and cackle.

 

[jimbo15563]

Paul,

My 32" barrel has a 1:104 twist, to emulate the Zephyr. They posted the following ballistic chart:

Ballistic Calculations of the 20 Bore Ball
Driven by 175 Grains of Black Rifle Powder
Muzzle Velocity of 1700 fps

Distance Velocity Energy Bullet Path
(yards) (fps) (ft-lbs) (inches)

30 1476 1644 1.6
40 1408 1497 2.0
50 1345 1366 2.2
60 1286 1249 2.2
70 1231 1145 2.0
80 1183 1056 1.6
90 1139 979 0.9
100 1101 915 0.0
110 1067 860 -1.2
120 1038 813 -2.7
130 1012 773 -4.6
140 988 737 -6.7
150 966 705 -9.2

I don't plan to shoot anything that heavy, BUT it's going to take a pretty healthy charge to put the required spin on the ball to achieve accuracy.

My plan is to sight it in at a maximum point blank range of 100 yards, figuring a kill zone 8" in height on a deer. The above chart has a MPBR of somewhere around 125 yards, which I don't think is necessary. I have my .50 flintlock shooting dead on at 80 yards. This enables me to take a 100 yard shot with no holdover. I won't shoot at a deer over 100 yards away with a muzzleloader.

I plan to start at 100 gr. of FF Goex and work from there. If I figured correctly, that means 3.7 drams. If I don't have to go much over that, I won't worry about the hearing issues on an occasional hunting shot.

Jimbo

 

[paulvallandigham]

Thanks for the data, Jim. I would recommend that you start with a load of 70 grains of FFg powder, and work up from there. I don't think you will need to go to 100 grains to find an accurate load for that rifle at 100 yds, and the mid-range trjectory will be small enough that you won't have to hold " under " much to hit a deer at 50 yds.

I still think that you have failed to understand how good a pure lead ball will be for killing. The 3/4 oz. of lead, once begun, just keeps on moving. I can't help but notice that even with that massive powder charge, the ball at 100 yds. is right at the speed of sound, well within the transonic zone, where it will be knocked around by the air filling in the vacuum that is slowly being reduced in size behind the ball. I believe you will be better served shooting a load that is at or under the speed of sound leaving your muzzle. The round ball will completely penetrate that deer on a broadside shot to the chest, and the pure lead ball will mushroom to dump some of its energy in the vital organs while making a quarter sized hole through the body, before exiting.

While you have that data, use a calculator to put a percentage to the loss of velocity, and energy for each of the ranges reported. You wil find that the biggest loss is in the first few yards. When you work up your own load, shoot off a bench, and put your chronograph out at 30 yds, then 50 yds, and then all the way back at 100 yds, and shoot over the screens to get the velocity. Put a metal deflector plate in front of the chronograph, if it is one of those like my Chrony, or Competition Electronic, that have the screens coming out the top of the unit, to deflect any bad shots, so you don't destroy the machine. I think you will find that even at a lower velocity, most of the velocity loss will be in the first 30 yds, or so, but that the two balls, one fast, and one slow, will arrive at the 100 yds target much closer than the raw data would suggest, using muzzle velocity alone.

Or, you can check the tables in the Lyman Shotshell Relaoding Manual, under " Patterns" and get the down range energy figures for slow and fast loads, and both drop, and time of travel for the fast and low velocity loads. Since shotgun pellets are round balls, too, they are acted on by air the same as air acts on your round ball in your .62 rifle.

 

[jimbo15563]

I'm sitting here on top of the mountain at noon and the temperature has gotten the whole way up to +5. I'm thinking about spring and shooting my new toy.

I'm going to take Paul's advice and start with a lighter load. I bought 2 cans of 2F Goex. (I use 3F in my .50's.) Now I'm thinking about patches and balls.

I'd like to try off-the-shelf products in the beginning. I have looked at TOTW, Dixie, and Thunder Ridge. Track has hand-cast balls in .600 and .610 at $7.50 per 25. Thunder Ridge has Buffalos in .600 and .610 at $11 per 50. They also have pre-lubed Ox Yoke patches in .010, .015, and .018 ticking. I'm leaning towards ordering both size balls and the 3 sizes of patches from Thunder Ridge. That should give me enough variety to work up a good load.

Spring Gobbler season is coming up. I'm hoping that the 1:104 twist will shoot shotgun loads. I haven't a clue as to how to go about this.

Advice would be much appreciated.

Jimbo

 

[jimbo15563]

Here is a progress update on my long-awaited underhammer:

We are working on the .62 barrel first. The sights are installed, the barrel has been mounted on the action. The breechplug attaches to the action ia 3 allen screws. When everything is set up, he will dimple the breechplug where the screws hit so that zero can be maintained when changing barrels.

John Taylor is working on some dovetailed ramrod thimbles, one of which will be used to attach the forend.

I need to order the rest of the parts:

1. A Safari Sling

2. Ramrod-I will order this in 7/16 from the advertiser on this site that builds them with a steel core. One tip will be straight and threaded. The other one will be concave, curved to fit a .62 cal ball and also serve as a jag (if possible). The other tip will be straight and threaded 10/32".

3. A flash cup for the nipple.

4. .62 cal accessories (jag, worm, puller, bore brush, etc) in 10/32" to fit the ramrod I'm ordering, as well as my brass range rod.

5. Balls, patches, wads, and musket caps.

The stock is curly maple and has a nice curl and grain. About 40 years ago, when I worked for Dave at a shooting range, he bought some curly maple. We took his pickup truck, loaded the wood, and brought it back to his shop. This is one of the pieces! The buttstock is in progress and a Pacmayr Declerator recoil pad has been mounted. Here is a photo of the stock as of Friday, Feb 9.

 

[jimbo15563]

Work is progressing on my the underhammer. I received my custom thimbles from John Taylor.

They have a 3/8" dovetail and the inner one provides an attachment point for the forend.

Nice work, John!

Thanks,
Jimbo

 

[paulvallandigham]

JImbo: That nipple enters directly into the barrel. Travel distance for the flash is going to be measured in 8ths of an inch. Don't be using Musket Caps on it. Use standard #11 percussion caps. The fire you get will be sufficient to ignite Black Powder. If you are going to use one of the substitute powders, then buy the Magnum #11 caps. The musket caps throw a lot more flame, and this just makes more fire that has to be controlled around the nipple. Its not going to ignite your powder charge any faster, but it can erode the inside of the barrel opposite the nipple by the repeated blasts of hot flame and gases. This will not happen over night, but why do it when its not needed?