Author Topic: First cannon (Read 3181 times)

keithinvestigations · « **on:** November 12, 2010, 03:57:01 PM »

Hi all I'm new here. I just sent off a check to Hern Iron for their Coehern mortar. I've been surfing here for a little while but still need some direction. I am very green here so please be patient with me. I am very familiar with modern firearms, but I've never loaded, fired or know squat about cannons.

I understand that I am going to have to get the vent tube drilled. Are there any instructions for this? I plan on taking this to a machine shop but I think I need some kind of direction instead of, drill me a vent hole as I doubt they do that often.

I also ordered the hardware for the sled and am going to get this built. Is there anyone here who could build this for me for a reasonable price? I'm not a woodworker but I guess I could try! lol

Where do I learn about type of powder, how much and basically how to fire this thing. Hern builds these but from what I gather you are on your own to figure everything out.

Thanks.

Ex 49'er · « **Reply #1 on:** November 12, 2010, 04:02:50 PM »

Welcome to the addicting world of black powder muzzle loading cannons and mortars.
You've come to the right place and your questions will answered. The people here are very knowledgeable and helpful. Congrats on your purchase.

keithinvestigations · « **Reply #2 on:** November 12, 2010, 04:10:47 PM »

Thanks. I would also like to ask if there is a book like "Cannoneering for Idiots" or something to that effect.

Double D · « **Reply #3 on:** November 12, 2010, 04:34:21 PM »

Cannoneering for idiots is found in about 75% of all You tube videos on cannon shooting. We have no idiot here.

A vent liner is a threaded tube that creates a continuous line from interior to exterior of the cannon. It seals the vent from erosive powder gases.

Here is my sketch of one.

You might contact Antique Ordnance Publishers and see if the will sell you plans for a Vent liner. They include te drawing in several of their plan sets.

Additionally look at our sticky called safe loads you will find guidance on how to develop loads for you mortar.

keithinvestigations · « **Reply #4 on:** November 12, 2010, 11:55:38 PM »

Thanks. I was referring to a series of books that gives basic instruction on a topic.

little seacoast · « **Reply #5 on:** November 13, 2010, 02:17:56 AM »

Hi and welcome to the madness. Recently bought a Hern "full size" Coehorn mortar in 2.25" bore (also available in 3") and built a base and stuff for it. If I can be of any help, please feel free to ask. There is nothing about the process you can not do with access to a few
tools like a drill press and table saw . Other tools help but are not essential.

Cat Whisperer · « **Reply #6 on:** November 13, 2010, 03:46:33 AM »

keithinvestigations --

WELCOME to the board!

Recommend making the diameter of the vent about 1.5x the diameter of the fuse you're going to use.
(Smaller fuse hole looses less pressure - important on the really small bores, ignore otherwise.)

When you drill the vent, be very careful when it's about to break through. If it hits in the rounded end, you'll have uneven material which tends to snap bits.
1/4 or 1/2" from the bottom may get away from that.

keithinvestigations · « **Reply #7 on:** November 13, 2010, 04:48:12 PM »

Thanks guys. As soon as my mortar arrives, I'm going to take it to a machine shop to drill the vent. What size should I have it drilled? Is there anything I should tell them other than the size and to drill it in the center of the indentation?

Thanks.

Double D · « **Reply #8 on:** November 13, 2010, 05:26:10 PM »

Depends on what you use for fuse...Quill is 4 mm so 4.5 mm might work, 3/16 but no more the .200.

GGaskill · « **Reply #9 on:** November 13, 2010, 05:30:59 PM »

This link is not to a book but it is to some rules for safe cannon loading:
http://artillerymanmagazine.com/safety_rules.html

keithinvestigations · « **Reply #10 on:** November 14, 2010, 03:03:36 AM »

Quote from: Double D on November 13, 2010, 05:26:10 PM

Depends on what you use for fuse...Quill is 4 mm so 4.5 mm might work, 3/16 but no more the .200.

ok, thanks.

Rickk · « **Reply #11 on:** November 14, 2010, 03:30:00 AM »

I had a machine shop drill a .200 hole in mine. It works very well with both 1/8" fuse and also 3/16" quills made from straws.

The hole in mine angles back, and enters the bore .400 (center of hole) from the face of the breech of the bore. If you drill straight in you will have issues hitting light charges.... you may be trying to pierce the projectile instead of the powder bag.

While 2-1/4 ounce blanks are fun for making noise, if you use the same charge behind a ball it will go into orbit. 100 grains of 1F will shoot a lead ball slightly over 100 yards. I have also used 2-1/8" OD concrete filled muffler pipe (6" long). 100 grains will shoot that close to 200 yards.

100 grains in a 2" OD powder bag is a very short charge, which is why you want to angle the vent slightly.

To load a 100 grain bag and get it to seat square is tricky. I wound up taping the bag to the ball with masking tape and loading them together.

To drill the hole, the machine shop use a piece of round stock that fit the bore snugly to hold the barrel. By trial and error, they set the bar up so that the drill hits the center of the vent dimple when the barrel is slid over it until it bottoms out, and so that, with the barrel removed, it hits a point .400 from the end of the round stock.

Cat Whisperer · « **Reply #12 on:** November 14, 2010, 03:39:03 AM »

Quote from: Rickk on November 14, 2010, 03:30:00 AM

... I have also used 2-1/8" OD concrete filled muffler pipe (6" long)...

Ooooo Ooooo Ooooo !!!!!

MUFFLER PIPE! I'll have to see if the local muffler installer guy will deal in 20' lengths at reasonable prices. The stuff comes in ALL sizes!

jeeper1 · « **Reply #13 on:** November 14, 2010, 10:15:13 AM »

Quote

MUFFLER PIPE! I'll have to see if the local muffler installer guy will deal in 20' lengths at reasonable prices. The stuff comes in ALL sizes!

Try a real auto parts store. Much more than 35 years ago I built a set of headers for a Buick 350 engine I dropped into a 68 jeep CJ5 by getting tubes and bends from a real auto parts store and welding then together. They ought to be much cheaper than a muffler shop.

keithinvestigations · « **Reply #14 on:** November 14, 2010, 10:19:38 AM »

Quote from: Rickk on November 14, 2010, 03:30:00 AM

I had a machine shop drill a .200 hole in mine. It works very well with both 1/8" fuse and also 3/16" quills made from straws.

The hole in mine angles back, and enters the bore .400 (center of hole) from the face of the breech of the bore. If you drill straight in you will have issues hitting light charges.... you may be trying to pierce the projectile instead of the powder bag.

While 2-1/4 ounce blanks are fun for making noise, if you use the same charge behind a ball it will go into orbit. 100 grains of 1F will shoot a lead ball slightly over 100 yards. I have also used 2-1/8" OD concrete filled muffler pipe (6" long). 100 grains will shoot that close to 200 yards.

100 grains in a 2" OD powder bag is a very short charge, which is why you want to angle the vent slightly.

To load a 100 grain bag and get it to seat square is tricky. I wound up taping the bag to the ball with masking tape and loading them together.

To drill the hole, the machine shop use a piece of round stock that fit the bore snugly to hold the barrel. By trial and error, they set the bar up so that the drill hits the center of the vent dimple when the barrel is slid over it until it bottoms out, and so that, with the barrel removed, it hits a point .400 from the end of the round stock.

Thanks Rick, this was exactly the instruction I was needing. I've ordered the Coehern Mortar from Hern Iron. What size of projectile do you think would be safe to shoot in a 3" bore? Are the charges you listed above the same if I were shooting something out of my barrel as opposed to the 2 1/4 one? Thanks.

keithinvestigations · « **Reply #15 on:** November 14, 2010, 10:39:46 AM »

Quote from: little seacoast on November 13, 2010, 02:17:56 AM

Hi and welcome to the madness. Recently bought a Hern "full size" Coehorn mortar in 2.25" bore (also available in 3") and built a base and stuff for it. If I can be of any help, please feel free to ask. There is nothing about the process you can not do with access to a few
tools like a drill press and table saw . Other tools help but are not essential.

Little seacoast, did you drill your vent the way Rickk mentions in his post above? Thanks.

keithinvestigations · « **Reply #16 on:** November 14, 2010, 10:43:16 AM »

Also, I was thinking of doing my base the same way you did yours. 45 degree angle indicative of CS but with a Union cannon, lol.

Here is a link I found regarding building of the sled: http://www.buckstix.com/MortarBed.htm

Could you or someone else give me the measurements for the Hern one? It should be a little bigger I think than the one in the link above. Thanks.

P.S. I really appreciate all the help here guys. I've been on other forums not related to this sport and not had such a positive experience. I realize I should research old posts and I did spend some time but couldn't find the specific's that are given here.

little seacoast · « **Reply #17 on:** November 15, 2010, 02:05:12 AM »

Hi KI, I drilled my vent with the advise of GGaskill. I drilled a large enough hole that I could tap it and insert a SS 9/16ths bolt into the hole. The bolt was center drilled with a 5/32nds bit ( I use 1/8th fuse), the bolt is ground at the tip to roughly match the tip profile of the 9/16ths bit. This seals the junction of the liner and cast Iron barrel and hopefully prevents corrosion. Refer to the pencil sketch by DD which shows this. Easier than it sounds thankfully.
The base measures 26 x 12 x 7" which was purely arbitrary on my part, it just looked right to me. I have since replaced the handles shown with the one's Hern sells, looks much better and easier to carry it too, that bugger will be HEAVY. If you do not have access to the tools, I can make you a base- materials and shipping only-it's a hobby. Best of luck with your mortar!

keithinvestigations · « **Reply #18 on:** November 15, 2010, 02:54:28 AM »

What is the advantage of having a SS threaded bolt instead of a straight vent hole? Corrosion? Thanks.

little seacoast · « **Reply #19 on:** November 15, 2010, 03:55:47 AM »

Prevailing wisdom has it that the junction of the liner and the casting is a prime place for corrosion caused by black powder to occur. Over time this may cause structural integrity problems in the barrel. Not today or next year but eventually. The vent hole would also erode to a larger diameter over time if simply drilled as a hole. The SS bolt or copper rod, or whatever you use as a vent liner gives you a way to seal the liner/casting interface and also allows you to replace the vent if the hole erodes to too large a size, again over time. All this is aimed at producing a barrel that will remain safe to use over time, like if your grand kids inherit the mortar and continue using it. There are numerous threads discussing this in the archives, most do a lot better job of explaining stuff than I can- I'm a newbie too.

keithinvestigations · « **Reply #20 on:** November 15, 2010, 04:10:26 AM »

Cool, thanks little seacoast. Did you angle your vent hole as described above?

Also, I want to take you up on your offer to build the mortar base and I don't mind paying you for your time! I sent you an email earlier, thanks.

Double D · « **Reply #21 on:** November 15, 2010, 06:20:38 AM »

Quote from: keithinvestigations on November 14, 2010, 10:39:46 AM

Quote from: little seacoast on November 13, 2010, 02:17:56 AM
Hi and welcome to the madness. Recently bought a Hern "full size" Coehorn mortar in 2.25" bore (also available in 3") and built a base and stuff for it. If I can be of any help, please feel free to ask. There is nothing about the process you can not do with access to a few
tools like a drill press and table saw . Other tools help but are not essential.

Little seacoast, did you drill your vent the way Rickk mentions in his post above? Thanks.

Go to our sticky Safe loads You will find the guidelines for determining maximum powder charge for you gun. Keep in mind when the say bore in cannon, in the mortar the powder chamber

The projectile needs to be slightly smaller than the bore and this difference is called windage. It is needed so the balls which my not have been perfectly round or become rusted will go in a dirty bore , especially in war time of. The rule of thumb windage is 1/40th of bore diameter. It's a rule of thim not a rule, its guidance and nothing more.

Here the simplified formula for finding windage. Bore diameter divided by 40 equals windage. Windage times 39 equal projectile size.

For now to get shooting find some common projectile that fits the bore and shoot it. But for the future contact our sponsors and have one of them make you a ball mould. Then have some zinc round balls made for your gun. Zinc more closely match the weight of solid iron shot for the bore. Zinc balls are also recoverable and if not dinged up form being shot into the rocks, can be reshot. I you can cast lead, but its mass require delicate d handly so they don't become damaged and usually need recast after being shot. The heavier lead also need reduced load to reduce pressure and lessen the effects on your gun.

keithinvestigations · « **Reply #22 on:** November 15, 2010, 01:37:03 PM »

Quote from: little seacoast on November 15, 2010, 02:05:12 AM

Hi KI, I drilled my vent with the advise of GGaskill. I drilled a large enough hole that I could tap it and insert a SS 9/16ths bolt into the hole. The bolt was center drilled with a 5/32nds bit ( I use 1/8th fuse), the bolt is ground at the tip to roughly match the tip profile of the 9/16ths bit. This seals the junction of the liner and cast Iron barrel and hopefully prevents corrosion. Refer to the pencil sketch by DD which shows this. Easier than it sounds thankfully.
The base measures 26 x 12 x 7" which was purely arbitrary on my part, it just looked right to me. I have since replaced the handles shown with the one's Hern sells, looks much better and easier to carry it too, that bugger will be HEAVY. If you do not have access to the tools, I can make you a base- materials and shipping only-it's a hobby. Best of luck with your mortar!

Little Seacoast, did you grind off the bolt head or leave it on? Sorry to ask so many questions, I'm learning!

little seacoast · « **Reply #23 on:** November 15, 2010, 01:53:59 PM »

Hi KI, I left the head on mine, but you could cut it off flush and cut a slot so that you could remove it with a screw driver. You may find that the bore of your Hern is a little more than 3", windage built in. A number of Soup and vegetable cans I measured today are 2.9" in diameter so that filled with concrete they will make suitable cheap and expendable ammo. Cast balls like DD mentions are nice but a mold and stuff will cost you. I pour mine with a wire loop set into the concrete that you can attach a streamer to, makes them easier to follow and find too. Currently involved in casting zinc balls for this mortar, lots of fun.
By all means check out the stickies for tips on building, loads, and lots of other stuff. Take your time and know for sure what you want to do. Regards, LS

Double D · « **Reply #24 on:** November 15, 2010, 02:36:11 PM »

Quote from: little seacoast on November 15, 2010, 02:05:12 AM

Hi KI, I drilled my vent with the advise of GGaskill. I drilled a large enough hole that I could tap it and insert a SS 9/16ths bolt into the hole. The bolt was center drilled with a 5/32nds bit ( I use 1/8th fuse), the bolt is ground at the tip to roughly match the tip profile of the 9/16ths bit. This seals the junction of the liner and cast Iron barrel and hopefully prevents corrosion. Refer to the pencil sketch by DD which shows this. Easier than it sounds thankfully.

Great idea... The light just went on....I have been making vent liners...I use them in my Golf ball mortars....I us socket head cap screws.

Get a socket head cap screw and install and fit like LSC suggests. Counter bore the hole so the head sinks below level and the top of the head is almost flush. File the protruding head to match barrel contour. Don't forget the high temp grease for the threads. This way the vent liner can be removed if need.

keithinvestigations · « **Reply #25 on:** November 15, 2010, 02:42:47 PM »

Thanks Douglas. Just got off the phone with little seacoast. You guys are great! Hopefully, I can help pass the torch on this knowledge when I get my stuff together. I'm really excited about getting this done.

keithinvestigations · « **Reply #26 on:** November 18, 2010, 02:01:45 PM »

Well, I couldn't wait for Hern to send me my mortar (two weeks) plus I have to get the base built, so....I ordered a Seacoast Dictator from Dominick Carpenter.

This will give me something to shoot while I wait for big brother!

Cat Whisperer · « **Reply #27 on:** November 18, 2010, 02:17:10 PM »

Isn't the addiction wonderful?

keithinvestigations · « **Reply #28 on:** November 18, 2010, 03:11:20 PM »

Yes, I'm addicted and I don't even have one yet, lol.

Ok, still gathering info about drilling my vent hole. Based on the picture above, the Coehorn mortar from Hern Iron Works has an indentation on the top. Is the middle of this indentation the best place to have the vent drilled?

keithinvestigations · « **Reply #29 on:** December 05, 2010, 03:41:43 PM »

Got my seacoast dictator in a week or so ago. Had fun shooting it yesterday. Dom's recommendations for shooting a golf ball are 2 1/4 teaspoons of black powder. I have to say, this is less than impressive. I have a few questions. Can I put more powder than what is recommended? Did Dom list that for liability reasons?

Why can't I patch with newspaper? I would think if I patched with newspaper I would get more pressure more bang and shoot further. I'm not talking about jamming the ball down, just a little tightness to up the charge.

I'm really new at this and don't want to be doing things I shouldn't. However, it needs much more bang that it gives.

The salute charges are a blast! I read somewhere here about not packing too hard. What would be wrong with packing newspaper on salute charges as tight as you can get it? Is it because you would be exposing too much of your hand (eg. not doing the under hand method because you are baring down with both hands, etc, etc) in front of the cannon or is it dangerous to beat down on the powder?

Another question, does everyone here swab down wet, dry and then powder on golf ball cannons? Is it absolutely necessary to swab down wet on such a small cannon? Does anyone here tape or hold the vent down while loading powder on small cannons?

Just trying to learn the ropes here, thanks.