Hand cannon project

[toadboy65]

So I have started a project I have been thinking about for a long while. The point of it is to gun train bird dogs. So it shoots a racquet ball.
First, an admission. I have never built a flintlock before, although I have built several percussion guns, and lots of cartridge guns. So that is why I went this way. I actually started out planning to do a wheellock, but decided that was more project than I wanted this time. Here is the barrel-


Yes, it is way more stout than it needs to be. At it's thinnest, the barrel wall is just shy of .2" thick. The breech is rounded to match the expected payload, and is further bored at .45". The smaller bore is long enough to put 130gr of powder in, plus a thick patch. I figured that would give me plenty to work with.
Here is the barrel profile as it is now-

Everything behind the touch hole is solid, and much of that will be cut down when I profile it to match the stock, which I have yet to design. But I do plan to try to stick to a design that is fairly close to mid-1700s German aesthetics. Since I am basically ignorant about flintlocks, I went with a set of Siler castings. I joined this forum to ask some questions about frizzen adjustments, but I read a bunch of old posts and figured those issues out.
Here is the geometry of the lock/barrel so far-

I am probably going to have to mill away some barrel at the front part of the lock so that the priming pan is up against the touch hole. My thinking is that I will run a bolt through the barrel to thread into the front part of the lock. There is plenty of room to do that without interfering with the bore. There is also some room to further contour the lock plate to fit the stock profile. I will be able to taper the barrel tang way down to match that profile as well.
Right now an issue I have is the touch hole. If I put the pan against the barrel flat as it is now, the touch hole is still .3" long. That seems a but much to me. I am toying with the idea of milling an extension of the pan the barrel a bit, but I just don't know if that is wise or necessary. Any input on that issue would be welcomed.
Also, I have tested the lock for firing, and shot balls from the barrel a few times. Since the end use is dog training, I would prefer that the cannon make sound more or less approximating a 12 gauge shotgun. So far, that is not happening, and I did really not expect much bang with 2fg black powder and a rubber ball projectile. I figure I would need a powder formulation that is a bit hotter. I have built the barrel so that it is not going to be the weak point, even if I tried to shoot the heavy iron projectiles that such guns were originally designed for.
I suspect the touch hole liner is the likely weak point. I made a liner out of very hard stainless with a 3/64" hole, but I really don't know what the best practice would be for that. Once again, advice from those with more experience would be welcome.
Anyway, that is where I am at right now.
Cheers- T

 

[Heelerau]

Look forward to seeing the end result ! Looks like a little grenade thrower !

 

[hawkeye2]

If you are going to fire a tennis ball over 130 grains you had better pack a lunch for your dog.

 

[toadboy65]

If you are going to fire a tennis ball over 130 grains you had better pack a lunch for your dog.

I do not expect to load the full capacity of powder. I wanted to bore the smaller diameter to accommodate somewhat more than the maximum theoretical powder load. I have been testing with 30gr of 2fg. As a side note, I tried using a rawhide wadding disk between the ball and the charge, and also fired it without the wadding. Neither seemed to damage the ball.
Also, the dog can catch a Frisbee in the air as far as I can throw it.

 

[toadboy65]

Another question for those with more experience-
I was fiddling with the geometry of the barrel and lock today, and I started to wonder about the priming pan. This sort of gun would always be fired while significantly elevated. I wonder if I should reshape the priming pan? I was thinking that if the pan was deeper towards the back, it would be less likely to spill out when the frizzen opens.
Once again, I am out of my area of knowledge. I might be overthinking this.

 

[Zonie]

Don't mess with the pan. It doesn't care which way the gun is aimed when it is fired.

A flintlock will fire just fine even if it is held upside down. In fact, it might fire better because as the pan cover is opened, the powder will start to fall directly into the path of the sparks.

 

[Felix the Cat]

Be careful with your charges with this.. mortar (..which is what you have) ballistics are a bit odd and looking at recommended loads for long guns will send you off piste!

You should be looking at small loads of fine(ish) powder. Most of the burn will take place in the chamber and not in the barrel and you do not want to be throwing clouds of unburned powder out of the bore. I would seriously be looking at very small load (maybe 20 odd grains) of FFFg and a softish wad such as triwall cardboard.. rawhide strikes me as a bit too stiff?

If you look at the charges that were used with real mortars, they are very small! I know that you only need ounces of powder to throw Propane cylinders significant distances! Have a look at what the Pumpkin and Bowling ball cannon fraternity are using as a guide!

 

[donk56]

Strange, I was just on another site (not BP), and someone posted this.

 

[Griz44Mag]

Is that the Rifle Shop's kit?
I just finished up the Haken kit.
The grenade launcher is on my bucket list. I will be watching this thread with great interest.

 

[toadboy65]

Be careful with your charges with this.. mortar (..which is what you have) ballistics are a bit odd and looking at recommended loads for long guns will send you off piste!

You should be looking at small loads of fine(ish) powder. Most of the burn will take place in the chamber and not in the barrel and you do not want to be throwing clouds of unburned powder out of the bore. I would seriously be looking at very small load (maybe 20 odd grains) of FFFg and a softish wad such as triwall cardboard.. rawhide strikes me as a bit too stiff?

If you look at the charges that were used with real mortars, they are very small! I know that you only need ounces of powder to throw Propane cylinders significant distances! Have a look at what the Pumpkin and Bowling ball cannon fraternity are using as a guide!

I used the rawhide primarily to keep the ball from being burnt. It was just a disk, a few thousandths larger than the bore. I used a regular lubed patch to hold the powder near the breech. The thing about using racquetballs is even though I have to really squish it in there, it pops right out when fired. I imagine a launching charge for the original iron projectile would be very different than what I need to throw the ball. It may even be that it is just not possible to use this barrel to shoot such a light ball more than 100 feet or so, which is what I get with 30gr of FFg.
But I will be very careful in working up to the right charge. I am a long way from holding the gun while firing it. So far, it has been fired while clamped in a stand and ignited with an ematch.

As for progress, I have been inletting the barrel to fit the lock, and removing metal from places where it is only adding excess weight. The barrel looks like this now-

I added the tang so that the stock will bear the weight of the barrel and the stress of firing, and to provide an anchor for the rear trigger guard bolt. Here is an image with the lock fitted-

I hope to get the stock designed and started in the next couple of days. If the project turns out to be successful, I will do engraving and inlay and make it presentable.

 

[Redmoon]

I feel like I need one of these in my life.

 

[toadboy65]

I feel like I need one of these in my life.

That is exactly what happened to me. But it happens over and over, with all sorts of different stuff. I have found, however, that if I make it myself, I don't have to explain to my wife why I need such things.
In this case, I sort of had the idea in the back of my mind for a long time. But this year I was working on a larger project, and ended up with just the right piece of 4150 tubing, plus lots of free shop time to spend on frivolous undertakings.

 

[Redmoon]

I hear you completely. I think I just get bored easily with things so I end up with a lot of hobbies. But this thing I like a lot lol.

 

[Questing]

Just worried about powder residue in your dogs mouth.........................bet it's fun to shoot!

 

[toot]

don't worry about powder residue in the dogs mouth it will not hurt it. after all what does our human mouths look and taste like after a reenactment, after tearing the ends off of paper cartridges, at a REV WAR or F& I BATTLE event. and then there is the old GUN POWDER TEA! after all it is only charcoal as it is needed in our diet. remember when we were kids and we and our dog drank out of the same mud puddle? well some of us may have? BTW. my black LAB has been chasing them fore years with BP residue on them, no ill effects.LOL!

 

[Nameless Hunter]

I feel like I need one of these in my life.

THAT bit of reasoning is how I ended up with a trebuchet that will throw a cantaloupe close to 300 yards...

 

[Questing]

don't worry about powder residue in the dogs mouth it will not hurt it. after all what does our human mouths look and taste like after a reenactment, after tearing the ends off of paper cartridges, at a REV WAR or F& I BATTLE event. and then there is the old GUN POWDER TEA! after all it is only charcoal as it is needed in our diet. remember when we were kids and we and our dog drank out of the same mud puddle? well some of us may have? BTW. my black LAB has been chasing them fore years with BP residue on them, no ill effects.LOL!

We have a 12 yr old Cocker that sleeps w/us. And she's had a few maladies in the past 2-3 years. Can't imagine life w/o a canine. She is a connoisseur of rabbit and cat **** which also makes her sick. I would like a Lab, but our 2 last Cockers have never given us and everyone around us undying love. Our Cute Canine Cuddle Cushion!

 

[toot]

glad you show so much love for your friend! don't ever change in that respect!! they say that you only get one good animal in a life time, but I think that they are all GOOD? remember LOVE ALL GOD'S CREATURES BIG & SMALL!!

 

[Carbon 6]

It may even be that it is just not possible to use this barrel to shoot such a light ball more than 100 feet or so, which is what I get with 30gr of FFg.

Tennis balls seem to have a range limit. I shoot them out of my howitzer and regardless of the powder charge, they max out around 200 yards. The balls actually flatten out like a pancake when shot and more powder just makes them nosedive straight into the ground faster. It's like they get to a certain point and then hit the brakes. Maybe if you filled the center of the ball with spray foam to keep the ball from flattening it might fly farther.

 

[Questing]

glad you show so much love for your friend! don't ever change in that respect!! they say that you only get one good animal in a life time, but I think that they are all GOOD? remember LOVE ALL GOD'S CREATURES BIG & SMALL!!

Mom (Mother Nature) must love us. We've had 4 dogs, and too many birds to count. And they have all been close to us. You know what the local kids miss most about school Cor19 closures? Meeting Mia and I at the school bus stop every morning!
We have a good neighborhood watch..........