Love of Muzzle Loaders: Jonathan Browning Barreled Underhammer

This one was created a while back and in another state, July/13/2012.
I thought you'd get a kick out this design.
The .50 caliber barrel as purchased at an Oregon gun show (PDX) $80 OTD, no plug, no sights.
Trying to find all of the parts to recreate an original, made the decision to make it into an underhammer, was quite easy.

See, no plug (snail). Two seal areas, three if you count the back flat.

Design the lock, the easy part. Cutting all of the parts out of raw steel, the harder part. Most all of the Harbor-Freight files have been replaced because of extreme usage.

The barrel as plugged and nipple installed.

Action mounted, with 8-32 button head screw just under the hammer.
Rear mounting screw goes through the tang (hole not shown) into the top portion of the hammer spring tapped hole. This arrangement puts the stock in a nice vise like grip. Front of barrel is pinned to the stock.

Full cock. This lock has a teeter-totter sear. Since this was installed the sear was too soft. Another sear was made today (Mar/4/2015) out of a portion of old slip-joint pliers. Really tough stuff. It works much better now. This picture shows the original hammer spring which did fail just behind the mounting screw. Another spring has replaced this one and looks the same.

Front sight is a small tube on top of a blade, rear sight is made up of broken pieces soldered together with an adjustment screw for elevation.

On the other side (not shown) is a stock notch so that a percussion cap can be installed from the side.
A brass plate has been added to the flat on the front of the stock to hide the end grain. No butt plate as yet.

Mar/05/2015
Range Report, .490 RB, blue tick patch, 25 yds, 70 gr of Goex Clear Shot FFFg. The Goex kept shooting low so I changed to 777 FFFg 70 gr and shot the high hit at the bottom right diamond, no other changes. Quite a bit difference in powders. Lowered the rear sight and continued shooting the next three above that small diamond.

Then shot this small group on another target with 777 FFFg 70 gr. I will try a .495 RB as the .490 RB's seem to go down the barrel very easy, can short start with thumb pressure. Maybe then the groups will tighten up some.

Mar/06/2015
A possible solution to needing .495 round balls.
Simulated golf balls in lead made from .490 round balls.
I had an old wood rasp that was sanded down to obtain flat teeth, I used that tool.
With the ball on a hard surface, rasp on top, letting the ball roll with the rasp multiple times and multiple directions. I get these ugly puppies and they are nestled in a towel inside of a repurposed Altoids tin:

They do measure .495 to .498 depending on the position measured. Since I only did 18 each (not wanting to go crazy and do 100 to find out that this does not work) they will have to be tried at the range.

Range Report, Mar/13/2015

25 yds, Goex Clear Shot FFFg 70 grs, Blue Tick Patch, Those fuzzy RB's above. It did seem to tighten up the groups, YAY! Now for some real .495 RB's since I only made 18 of those fuzzy ones.

Now What?

Fuzzy utube video

May/24/2015
Shot this target with real Goex FFFg.
25 yds, 50gr of FFFg, .495 RB, 0.15 patch lubed with bore-butter.

Today, Nov/16/2015
I was working on this rifle when the hammer spring broke just past it's mounting screw. So, off to the "shop" to make another one.

The new spring, from a old handsaw blade.