Mini cannon bores

Topical Discussions include anything pertaining to Gunsmithing.

Moderators: JackF, Harold_V

Post Reply
thirtycal
Posts: 32
Joined: Sat Sep 03, 2011 10:04 pm
Location: Blossom, TX

Mini cannon bores

Post by thirtycal »

Need some advise. I have searched the web and have found answers all over the place. What should I bore out a mini cannon to in 36,45, or 50 cal. Maybe a better question is what clearance should smooth bore have with the projectile?
User avatar
steamin10
Posts: 6712
Joined: Sun Jun 08, 2003 11:52 pm
Location: NW Indiana. Close to Lake Michigan S. tip

Re: Mini cannon bores

Post by steamin10 »

I dont encourage shooting a ball from a model cannon.

.45 cal round ball fits a 1/2 inch smooth bore with paper wad.

Watch your reloads, and swab/brush often. Ruin your day with a pre/load flash.
Big Dave, former Millwright, Electrician, Environmental conditioning, and back yard Fixxit guy. Now retired, persuing boats, trains, and broken relics.
We have enough youth, how about a fountain of Smart. My computer beat me at chess, but not kickboxing
It is not getting caught in the rain, its learning to dance in it. People saying good morning, should have to prove it.
jpfalt
Posts: 982
Joined: Sun Jan 05, 2003 12:55 pm

Re: Mini cannon bores

Post by jpfalt »

Bore at whatever works for you.

The originals, circa 1700, usually ran 1/30 to 1/64 of the diameter clearance between the ball and bore. If tilted down, it was likely that the loaded ball would roll out.

If you intend to actually shoot the thing, you want to proof test. The circa 1700 test was double shot, double powder. Measure and inspect after the shot to confirm no cracks, no deformation. The tests I have done were out in the country, dig a hole, install loaded cannon with fuse, put planks and sandbags over the hole, light fuse and vacate the area. After the big noise, recover and inspect. It's not a whole lot different than shooting anvils, but done under sand bags.
User avatar
Dave_C
Posts: 960
Joined: Mon Apr 21, 2008 10:34 am
Location: Springfield. MO.

Re: Mini cannon bores

Post by Dave_C »

thirtycal,

I have one of these "small" cannons that I bought as a kit 30 years ago. Fired it a few times, no big deal but there is a reason you see the old field cannons using a swab after each firing. You have to get the embers out of the bore before you put in a new load or it goes off in your face.

Now for clearance, I don't recall if my cannon is a 45 cal or not but I think it is. With a cloth patch the ball has considerable drag when I press it in. So whatever ball you use plus the double thickenss of the patch you intend to use and you should be good on clearance.

Dave C.
I learn something new every day! Problem is I forget two.
thirtycal
Posts: 32
Joined: Sat Sep 03, 2011 10:04 pm
Location: Blossom, TX

Re: Mini cannon bores

Post by thirtycal »

I am making it from a piece of scrap I have. It was actually an idler arm from large truck. The OD is 1.16" I am going to go with a 45 cal so lets say 1/2" bore this gives me roughly 1/4" wall. Which is more than what my flint lock pistol and percussion cap rifle which only have 1/8" walls. I will also test it with a triple charge before I ever shoot it with out a barrier between it and my self. Fortunately I am out in the country with 27 acres so test firing will be easy.
GeorgeGaskill

Re: Mini cannon bores

Post by GeorgeGaskill »

Best way to select bore size is to determine what you are going to use for shot, then drill bore 2.5% larger. The clearance (called windage) allows for diametral imperfections and the accumulation of black powder fouling. Don't use powder charges for muzzleloading rifles because they are assuming you will be adding the mass of your body to that of the rifle while that is not the case with model artillery. Start with a really low powder charge and stop before the recoil becomes unmanageable.
thirtycal
Posts: 32
Joined: Sat Sep 03, 2011 10:04 pm
Location: Blossom, TX

Re: Mini cannon bores

Post by thirtycal »

I have found a sight with recommended loads. Yeah that whole equal and opposite reaction thing is a bear. Unless we get some more rain around here I am not going to be shooting it anyway.
Post Reply