New Smoothbore Pistol From Old Kentucky Rifle, and Loads for it.

[Daekar]

A while back I started a thread in the pistol shotshells section where I examined the performance of a large prototype 3D printed shotshell in 357 magnum, and while it certainly worked as intended (a full 1/2 oz, no problem), the dreaded rifling donut was still present. I expressed frustration with this, and said that I wished I could find a neglected barrel to bore the rifling out of. Several folks very rightly pointed out that our idiotic laws would render a single-shot small-caliber low-power short-range gun like this illegal, and I more or less dropped the idea when I realized how expensive it would be to get a minimum-length 38 cal smoothbore custom barrel.

Then one of the posters put up a link to this:
https://www.davide-pedersoli.com/en/product/harper-s-ferry-conversion-pistol

As a side note, why don't more modern pistols look this good? Seriously: Ruger, S&W, somebody... get on that.

Anyway, that got me thinking about an old 45cal Kentucky long rifle my wife's grandpa had given me years ago. It looked nice on the outside once I cleaned it up, but the bore was so pitted that you couldn't hit the ocean with it if you fired it over the waves from the end of a dock. It had just cleaned the bore as well as I could and protected it from rust and there it sat for years, unfired and useless. So... I... got out the hacksaw. And a drill. And many other tools and lubes and various doodads. The goal? A 50 caliber smoothbore something that could shoot donut-free custom shot loads without causing problems with the ATF or my checking account.

In retrospect, I should have bought a long 1/2" drill bit which would have allowed me to drill the rifling out of a longer barrel, but I didn't do that. So, I eyeballed the length of the barrel, the length of the 1/2" bit I had, and cut the thing off. You can imagine how much barrel I removed, those Kentucky long rifles are well named! And then I started cutting and sanding on the stock... and things kind of get fuzzy after that until I found myself epoxy bedding the barrel.

So... this is what I ended up with:
https://snz04pap002files.storage.live.com/y4mExIrb3dAxOHQiwdpJaRJEfZPHWW3ohi6Udcdbv4W0QhDCkE YUCjP_xutXBIBtj7pEj-peipWJp7lzQQgZpUf29nDG7LwXI9I6TK4UYB2Ci9TXOtW3mvK3 M2gn_cPSqbwA0gELmP2RyAulMYJkiLWOOT0p9yU1DJNiIPVG2V 7zT9DTZGZgEbD2aHb5DyA7ZP_?width=1024&height=396&cropmode=none
https://snz04pap002files.storage.live.com/y4mQjuz9qmfyPwiMl28aKkMpYPreT7tt4JdY3KMxz6LO0ErDU-pnFfgXDiaVsRtXIDE-HmDybmE0eCU-Wb8WUL47BNbzcguUxseUKXJfB_3u7Fu0Y12fSnwkZhZx5Q8Vzm NbkBRUuHHuIXkKasDBktAWCS2QWv85gNvbaKG8FYecnScqzbAa vYQFFcZlRxDnqjX?width=1024&height=569&cropmode=none
Doesn't hold a candle to the Harper's Ferry conversion linked above, but it does make useful something which was otherwise going to rot in the corner until I threw it away. Or, that's the hope, anyway.

Which is a very long way of starting to ask the question: If this were yours, how would you build a shot load for it? I have about 5000 steel BBs which I'm planning to use (since I don't own a BB gun... don't ask me where they came from) as shot, so I'm not super concerned about the shot being misshapen by acceleration. I have been hunting around and it looks like most normal BP shotgun loads involve an overpowder card, some kind of big fat lubed chunk of felt or something, and an overshot card.

I have a package of these coming:
https://www.midwayusa.com/product/1010391437?pid=814623

Could I just, say, use two as overpowder, slather some bore butter on a third, add a volume of shot equal to the charge, and then a single overshot card?

The other more important question is, what would you estimate is a safe charge for this? It started out 45 cal and is now 50cal smoothbore, but I'm pretty confident that the back area of the barrel wasn't touched by the bit. so it's still more or less factory. The gun tolerated 100gr loads when unaltered but that seems quite a lot for a pistol regardless of condition. I'm confident that pressure in a shot load won't be as high as a tightly-patched ball, but I'm also a BP novice so... well, you know what they say about assumptions.

[fastdadio]

Looks like a right proper snake blaster you got there. Or just about anything else for that matter. (I posted the link to the Harpers Ferry.) Having done this before with a Kentucky pistol kit. I'd start with about 30 grs 3f and an equal volume of shot and start playing around. That's where I ended up as a workable, effective load. Have fun with it. I doubt you can over load it to unsafe pressures no matter how much powder/payload you stuff in it. But you will find a load level that is just plain too much and it will take the fun out of it. I loaded everything you can imagine in mine. Work the powder charge from 20 grs up until you pull the trigger and say to yourself "yowzer! ain't gonna do that again" and then back it down a bit. Warning on using steel BB's, they ricochet wildly, and wear safety glasses. Keep us posted on your progress and some shot pattern pics.

[Der Gebirgsjager]

An honest critique-- Because of the shape of the stock's grip I don't believe you'll want too high a load. The recoil will be pretty much straight back, cushioned only by the side of your hand, and you're likely to hurt your wrist or trigger finger. Were it mine I would cut it off about where the first joints of your ring and little fingers are shown in the photo and add a downward sloping grip such as shown in the Pedersoli photos. This could be done fairly easily by a skilled wood worker-- dovetail the new part in place with some epoxy in the joint. Also, I'd consider removing the finger rest your middle finger is resting on in the photo, as a curved grip will allow the pistol to recoil upward and a bit backward in rotation, and the finger in that location will resist the rotational movement and perhaps be battered. Most trigger guards are rounded for a reason. True, antique dueling and target pistols had the finger rest, but the load and caliber were smaller, the grip curved. As for the quantity of black powder or Pyrodex to be used as a propellant, I'd start low and work up, perhaps at about 28 gr. and consider a Colt Walker loading as about maximum. Bravo on the idea to salvage an unusable gun and create something useful.

DG

[Eddie2002]

Nice conversion, I've built three .50 caliber smoothies, two flint locks and one cap lock. I proofed them with 70 grains of 3F pushing double patched round balls with no problems. Since your's is a cut down rifle I can't see how any reasonable load would cause a problem. A load of 25 grains of 3F and a patched RB would work just fine. Can't help with a shot load. Nice pop gun have fun with it.

[Texas by God]

I'd just use newspaper for wadding to shoot the BBs- and don't shoot steel with it, Ralphie- you'll put both eyes out![emoji16]
Try spent primers, too.
With real lead shot though, that .50cal can almost be a 28 gauge I'd imagine.
I concur with DG about the grip and trigger guard but that's still a neat pistol!

Sent from my SM-A716U using Tapatalk

[LAGS]

I like the shape of your stock.
It might be a little hard to control with heavy loads.
But since it isn't a repeating gun , there isn't much to worry about.
I have a .45 9" long round percussion barrel that I am going to build my own design of pistol with.
I found a percussion lock that I will use.
Now it is a matter of getting all my other BP rifles and kits built so I can work on a design for the pistol.

[fastdadio]

I'd just use newspaper for wadding to shoot the BBs- and don't shoot steel with it, Ralphie- you'll put both eyes out![emoji16]
Try spent primers, too.
With real lead shot though, that .50cal can almost be a 28 gauge I'd imagine.
I concur with DG about the grip and trigger guard but that's still a neat pistol!

Sent from my SM-A716U using Tapatalk

Newspaper wadding will set dry grass on fire, so will cotton. Ask me how I know.... I used 28 ga. shot cups in my .58, they were a bit tight, but worked well. Two .535 round balls in a 28ga shot cup fired from my .58 Hawken would hit about 4" apart @ 100 yds.

[Daekar]

An honest critique-- Because of the shape of the stock's grip I don't believe you'll want too high a load. The recoil will be pretty much straight back, cushioned only by the side of your hand, and you're likely to hurt your wrist or trigger finger.
DG
Thanks for the feedback! I was actually concerned about the shape too, but it was outweighed by my anxiety over removing too much material... I would prefer to keep it one piece of wood if possible. The plan is to shoot it and see how it feels and points in reality. If it feels good, then it stays as is, and is it doesn't then I think the act of shooting will give me more information about exactly what is lacking.

Believe it or not, I actually removed quite a bit of material to make it less straight and more pistolish (pistolly?), the first time I picked it up it felt like you had to go through contortions to point it at anything except the ceiling!

[Daekar]

Looks like a right proper snake blaster you got there. Or just about anything else for that matter. (I posted the link to the Harpers Ferry.) Having done this before with a Kentucky pistol kit. I'd start with about 30 grs 3f and an equal volume of shot and start playing around. That's where I ended up as a workable, effective load. Have fun with it. I doubt you can over load it to unsafe pressures no matter how much powder/payload you stuff in it. But you will find a load level that is just plain too much and it will take the fun out of it. I loaded everything you can imagine in mine. Work the powder charge from 20 grs up until you pull the trigger and say to yourself "yowzer! ain't gonna do that again" and then back it down a bit. Warning on using steel BB's, they ricochet wildly, and wear safety glasses. Keep us posted on your progress and some shot pattern pics.

Oooh, thanks for the warning on the BBs, that had never occurred to me. Safety glasses it is!

While I won't be making any foolish attempts to test the theory, it's comforting to hear that the action is likely to be stronger than any payload/charge combination I'm likely to want to use. I'll start where you recommended and just see how things go!

[toot]

I think with the straight stock it will be hard to get youe wrist in line to get it on target. it seems to want to point up? might shoot high?

[Daekar]

No comprehensive range report yet, the weather has been lousy today, but my 50 cal wads finally arrived and I did fire a few shots with 777. 20gr volumetric equivalent to BP felt like way too little (barely a poof) , so I ended up at 40gr volumetric. Tried equal volume steel BBs and at about 7 yards the pattern was about the size of a poster board. Going to have to fiddle with that to see about shrinking it. Maybe a 3D printed shot cup? It also handled the 45 cal round balls just fine, and shot straight enough. More to come!

[LAGS]

A shot cup will help with the pattern on a shotgun.
But your barrel is so short , it may not make a difference.
But Hay.
Give it a try.
Or try a paper tube bean bag for your shot.