# Ways to bore a cannon barrel



## brasssmanget (Jan 24, 2017)

I am working on a steel cannon and have managed to drill into it the full needed length of 15.50" - but only with a 7/16" extended drill. Took quite awhile going .50 " at a time and then clearing chips and re-lubricating with cooling juice. My problem now is how to complete the larger bore size to that length?  I stepped up with a 5/8" / then 1" / and finally a 1.125" shorter drill getting in almost 6.0" total, but all these larger drills are very short, and I'm not sure how to extend them safely. Boring bars might be an answer, but right now at 7/16" I have nothing long enough or small enough to fit into the existing hole. Any ideas / suggestions on how to proceed with this task would be appreciated. I'm working with an older Heavy 10 with a 4' bed, so reach is not an issue as long is any tool doesn't exceed 16" - but I would thing there would be a lot of flex in a boring bar that long and narrow enough to work in the existing hole....

Thanks in advance....


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## rgray (Jan 24, 2017)

I have an extension I made for a S+D drill that is just a piece of 3/4 round stock drilled to 1/2 on one end with 4 set screws to hold the drill shank. 2 set screws in line and 2 at 90 degrees. Mine is 6" but you could be made any length needed. Then the other end is turned down to 1/2  for the drill chuck.
once you get to the 1.125 size then proceed with a boring bar.


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## Jeffers (Jan 24, 2017)

brasssmanget said:


> I am working on a steel cannon and have managed to drill into it the full needed length of 15.50" - but only with a 7/16" extended drill. Took quite awhile going .50 " at a time and then clearing chips and re-lubricating with cooling juice. My problem now is how to complete the larger bore size to that length?  I stepped up with a 5/8" / then 1" / and finally a 1.125" shorter drill getting in almost 6.0" total, but all these larger drills are very short, and I'm not sure how to extend them safely. Boring bars might be an answer, but right now at 7/16" I have nothing long enough or small enough to fit into the existing hole. Any ideas / suggestions on how to proceed with this task would be appreciated. I'm working with an older Heavy 10 with a 4' bed, so reach is not an issue as long is any tool doesn't exceed 16" - but I would thing there would be a lot of flex in a boring bar that long and narrow enough to work in the existing hole....
> 
> Thanks in advance....



I used a Plumber's/electrician s extended 3/4 drill bit here is how I did mine:
http://www.practicalmachinist.com/vb/south-bend-lathes/cannon-barrel-boring-266384/




Sent from my iPhone using Tapatalk


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## brasssmanget (Jan 24, 2017)

Thanks for the replies. rgray what you suggested is just about what I had been contemplating. I guess I just needed to hear someone else say it too.  I am definitely leaning that way, but will wait for any other ideas that may arise....
Jeffers thanks for your link. I had seen that while over on that forum awhile back and was impressed. You did a fine job on that project. I am a little worried about too much chatter - may have to go with idea #1 to ease my concerns....we wil see, and I will keep the thread updated....


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## rwm (Jan 24, 2017)

You can make a gun drill:

http://www.sterlinggundrills.com/gun-drills-half-round.php

Robert


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## Tony Wells (Jan 24, 2017)

I've used Sterling gun drills with great success, but I don't believe they will work with a predrilled hole. You might consider a core drill, or it might take 2 to get to your size. They have a generous blunt, non-cutting center and are expected to be used only to enlarge existing holes.

If you choose to make an extension for a twist drill, try to turn the shank back far enough to get into the back end of the flutes. You will have less problem getting coolant in and chips out. Yes, it does get harder as you remove the MT if that's what you start with, but it can be done. Or you can gouge out some semblance of flutes in what remains of the smooth drill OD with an angle grinder for the same purpose. It doesn't have to be pretty to work.


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## brasssmanget (Jan 24, 2017)

I spent some time working up an extension today - had to remove the cannon body from the 3 jaw to work on the bar, so I'm continuing with other parts before re-chucking the large piece - for now anyhow.....
I will have to manufacture a sleeved front end to slip over the front as I had to turn that part down to fit my steady rest - only accepted 3" or less Diameter....bummer.....


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## rwm (Jan 24, 2017)

This all sounds exciting but your pics are not showing up?!
Robert


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## Rick Berk (Jan 25, 2017)

I might be able to help you, I have a piloted step drill that is 1.25 OD and threaded for an extension shaft, overall length is about 14" and I would be willing to loan it to you. I made it for a job and used it once to drill a 30" bronze cannon barrel back in 1979. If interested let me know and I'll see if I can find it.


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## brasssmanget (Jan 25, 2017)

Rick Berk said:


> I might be able to help you, I have a piloted step drill that is 1.25 OD and threaded for an extension shaft, overall length is about 14" and I would be willing to loan it to you. I made it for a job and used it once to drill a 30" bronze cannon barrel back in 1979. If interested let me know and I'll see if I can find it.



I really appreciate that offer, and I am actually very interested in at least seeing a picture if you have one available. Sounds like an interesting drill. I am going to try my extension and see how successful that is - if no luck I will contact you about your offer.


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## brasssmanget (Jan 25, 2017)

Gunrunner you need to order a set of these for the Z axis hand crank. Bill did you just spit coffee on your monitor? :rofl:

View attachment 253356


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## rwm (Jan 25, 2017)

Sweet! Great work.
Robert


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## brasssmanget (Jan 28, 2017)

OK Gents. I am at a crossroad now - not sure which way to go again. I now have the entire bore drilled out to 1.125" to a depth of 16". Of course the finish leaves a lot to be desired, not to mention I'd like to clean it up and enlarge it to 1.200 / 1.250 inches. If I go with a boring bar, what is the maximum shaft size I could use? I'm thinking 1" is too large and won't allow chips to move freely. .750 inch seems like it would be a little flexible at 16" length, and might not achieve the desired consistency for diameter. Any ideas or other options open to me that won't cost an arm and a leg?  Really need some guidance here......


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## 4GSR (Jan 29, 2017)

Your not going to get a small boring bar to bore that deep without all sorts of chatter and havic.  Even a solid carbide boring bar you going to have similar problems.  Your best practical way to finish the bore is to ream it with several sizes of reamers until the size you want is reached.  

Now, if you want, you could make a reaming head that has wear pads mounted at 90 and 180 degrees from the cutter and the cutter is set up to skive the surface of the hole.  The cutter would have to be retracted many times to remove chips and add cutting oil.  Unless you use pressurized coolant as the do on larger deep hold drilling/ reaming machines are set up to do.  Ken


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## kd4gij (Jan 29, 2017)

I would use a MT drill bit just under the final size and long enough.


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## brasssmanget (Jan 30, 2017)

Thanks guys -still scratching my head and pondering a solution here.....


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## mmcmdl (Jan 30, 2017)

Expansion reamer sounds like the way to go from this point .


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## Ianagos (Jan 30, 2017)

Just get a reamer and add an extension like you have I picked up three carbide reamers on eBay right around the size you need if you have enough power might be able to take it straight to finish size but prob not. Get a 1-3/16 sd drill use it in your extension and get a 1 1/4 reamer and be done close enough for a cannon. Also I would feed the reamer with carriage feed and prob rig a hose (maybe 1/4 copper line for stiffness and air if you don't have coolant) pumping some coolant in there to flush chips. I recommend the carriage for feeding the drill too so it's easy to retract and insert.


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## Cadillac STS (Jan 30, 2017)

If it is for actual firing often times those have a smaller diameter powder charge area at the bottom.  Like a 3/4 inch diameter on that and 1.5 inches deep or so.  That way there is more metal where the explosion occurs and your fuse hole is to the back of that cavity.


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## Ianagos (Jan 30, 2017)

Cadillac STS said:


> If it is for actual firing often times those have a smaller diameter powder charge area at the bottom.  Like a 3/4 inch diameter on that and 1.5 inches deep or so.  That way there is more metal where the explosion occurs and your fuse hole is to the back of that cavity.



I have heard of that on larger cannons but I feel like this cannon being steel and relatively small bore should be ok. But I think you are right.


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## 4GSR (Jan 30, 2017)

mmcmdl said:


> Expansion reamer sounds like the way to go from this point .


You mean a adjustable blade shell reamer?  If you can still find them.


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## mmcmdl (Jan 30, 2017)

4gsr said:


> You mean a adjustable blade shell reamer?  If you can still find them.



That's them . I guess they are still out there . We use them all the time for cleaning up holes at work .


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## Cadillac STS (Jan 31, 2017)

For projectiles there is need for precision.  For a black powder signal cannon (No projectile) there is less need to be so exact on dimension and after a few shots it will have a nice black patina inside.  

 Problem with projectiles is if it sticks then you just have a pipe bomb.


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## brasssmanget (Jan 31, 2017)

Originally planned on trying with projectiles, but I am rethinking that now. A loose (er) fitting patched and well lubed projo was my thought in the beginning, but I sure would hate to have a squib load in the cannon......might ruin a perfectly good day! 

I have ordered two more step up diameter sized drill bits (1 3/16 and 1 7/32) and will see if I can smooth it out a little this way.....


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## 4GSR (Jan 31, 2017)

Need to buy you a chucking reamer or shell reamer to finish out the hole to the size you want.  Drill bit is not going to smooth out the hole for you.  I have a 1.250 shell reamer and a arbor that you more than welcome to use if you like.  My next smaller reamer is 1.125", I believe you are already at that hole size.  Ken


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## brasssmanget (Feb 1, 2017)

Thanks Ken - I appreciate that offer. I guess my concern is what minimum hole size do you think I need / recommend to use a 1.250 reamer - I would think 1.125 is not going to cut it. (pardon the pun) Is your arbor an MT arbor or straight shank? Length? I may have to do some improvising to get the 14"-15" depth needed. I could leave the back 2" smaller as it's just a powder charge area......


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## brasssmanget (Feb 5, 2017)

Still waiting on the 1 3/16 drill bit, but another question came up. Anyone have experience with Loctite 680? I'm considering anchoring the pintle bolts in the sidewalls of the cannon with this. The fit is very tight, but slip-fit size. I cut slits do let the excess escape when pressing in the bolts. Do you think this is strong enough, or is welding required?? Holes are 5/8"D X 3/4" deep.


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## Cadillac STS (Feb 5, 2017)

I'd just go no projectile and call it a signal cannon.  Will get PLENTY of attention with it and will be safer.

Are you going to make a wooden carriage mount with wheels?


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## Terrywerm (Feb 5, 2017)

Cadillac STS said:


> If it is for actual firing often times those have a smaller diameter powder charge area at the bottom.  Like a 3/4 inch diameter on that and 1.5 inches deep or so.  That way there is more metal where the explosion occurs and your fuse hole is to the back of that cavity.



Typically howitzers and mortars had chambers in them, an area of reduced diameter. These types of artillery used less powder and the projectile followed more of an arc to its target. Cannons were used for a flatter trajectory and required more powder for the same size projectile. Chambered pieces require that the entire chamber is full of powder, there cannot be any air space. Thus you cannot vary the charge in them as you can in regular cannon.



brasssmanget said:


> Originally planned on trying with projectiles, but I am rethinking that now. A loose (er) fitting patched and well lubed projo was my thought in the beginning, but I sure would hate to have a squib load in the cannon......might ruin a perfectly good day!



You should be all right with lubed and patched projectiles, if you can find them in the proper diameter and consistent in size. If you have to work hard to get them pushed down the barrel, or hammer them in, they are too tight. They should slide easily down the barrel with just a bit of resistance. If your projectiles are a little too small in diameter, wad up a piece of paper or two and ram it down the barrel on top of your powder charge creating a wad, then insert the projectile and ram it home on top of the wad. Just make absolutely certain that there is no air space between the powder charge and the projectile as the results can be disastrous.

A squib shouldn't cause a problem except that it will be difficult to extract the projectile from the barrel once it occurs. As long as you put in the proper volume of powder, the projectile should exit the barrel quite nicely. Squibs typically occur when you either have way too much space between the projectile and the inner surface of the barrel, allowing the hot gasses to escape around the projectile, or if you use too little powder, failing to generate enough force to eject the projectile.



brasssmanget said:


> Anyone have experience with Loctite 680? I'm considering anchoring the pintle bolts in the sidewalls of the cannon with this. The fit is very tight, but slip-fit size. I cut slits do let the excess escape when pressing in the bolts. Do you think this is strong enough, or is welding required?? Holes are 5/8"D X 3/4" deep.



By pintle bolts I assume you are referring to the trunnions, is this correct?  See this web page for some proper nomenclature so that we know we are talking about the same thing: *The Piece - Basic Terminology*
Personally I would remake the trunnions and make them a solid press fit in the barrel, a shrink fit might be even better. Loctite is great stuff, but I would not trust it to keep the trunnions in place. I don't want to rain on your project, but I don't want to see you getting hurt either! The trunnions need to be very firmly seated. You could also try threading the trunnions and their holes, then use Loctite when you thread them in so that they do not loosen up, but I would not rely on Loctite to secure a slip fit in this application.

I have one last question for you: What are you planning to use for your powder charge, namely type and grade of powder and quantity?


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## brasssmanget (Feb 6, 2017)

yes - trunnions.  I'm used to referring to the pintle pads and bolts on a 1919, so I carried that over - my mistake.....
I'll probably go with a silver solder or weld - I made some "caps" to cover around the seem at the barrel.
Haven't even thought about charge weight yet. Planned on doing research on that when the time comes up. This thing is a long way from being functional right now....thanks for the link to that page!


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## Terrywerm (Feb 7, 2017)

Ah, now I understand. It's good that we are on the same page. Proper terminology is highly over rated anyway. 

Here is one other thing that you may not have considered and I forgot to mention: Did you leave a sharp corner at the bottom of the bore?  The general rule of thumb is that the 'corner' at the bottom of the barrel needs to be radiused and should not be a sharp corner. Sharp corners tend to promote cracking in the breech area, definitely not something that you want.


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## dlane (Feb 7, 2017)

This chart is for black power , the first couple shots I fired out of mine were double charged and I was behind a solid concrete wall 20 yards away in a safe place to make sure it wouldn't blow up, it didn't 
The listed charge for my bore 3/4" work fine, dogs close by stay quiet for a long time after it goes off 
clamped my trunnions on grove in barrel welded to 3/16 strap haven't had a problem with them.
Mine is not a replica , it is fuse fired 



I had a lot of extra powder to use up.


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## Chipper5783 (Feb 7, 2017)

How are you making out on the final boring of that barrel?  Did you consider making up a piloted boring bar (of course then you would need a breech plug)?  Ideally, the bed of the lathe ought to be 2x the length of the barrel so as to bore it in one shot.  It is going to be a home made job.  All it is, is a long bar with a single point cutter at the mid point.  The far end (the pilot) does not need to be full size.  The hole in the far end (breech end) of the barrel could be the steady for the far end of the bar, or you you install a bushing in the spindle bore of your lathe.  You may wish to add a bushing at the muzzle end as well.  Clearing chips could be a problem, so only take a small amount (perhaps blow air down the pilot support and leave an opening at the muzzle end steady to clear chips?).

You could also bolt the barrel to the carriage and mount the boring bar between centers (amounts to the same thing).
Basically you would be setting up your lathe as a line boring machine - run some searches on line boring with a lathe.


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## brasssmanget (Feb 8, 2017)

Terry I did leave a radius at the bottom - also this will end up being slightly smaller in diameter for the last 3" +/-. 

Thanks for the chart dlane - nice looking finished product!

Chipper - I did the bore in steps from 1/4" on up to 1 1/8" going 2" at a time, using a lot of cutting fluid and clearing chips each segment. Very long mundane drawn out process. My bed is 4', so no issues getting 16" deep in the bore with the steady rest.....I may just try a bushing w/set screw on the last drill bit before reaming....just to help smooth it out a little. Thanks.


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## Ianagos (Feb 8, 2017)

Are you using the tailstock or carriage to feed?


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## brasssmanget (Feb 8, 2017)

A 6" vise is overkill for a RF45 style mill. A 4" is more appropiate for that size mill & IMO 5" max. I have a 5" GMT vise on my PM45 & it's slightly too big. Not enough Y axis travel to make use of the 5" full capacity. Better to save your money rather than getting something too big & most importantly the weight. I take my vise of the table quite often, a 6" is still light enough for me to be carried by hand but I'm glad I have a 5". I also have a 4" vise as well. I prefer the 5" though.

But those GMT 6" Premium vises are pretty nice. I'd love to have one but don't need one on my current mill. But if you plan on upgrading to a full size knee mill in the future than the 6" will be perfect.


Here's what the 5" looks like on my mill.




I couldn't even complete this cut without my bellows & DRO scale getting in the way. Not enough Y travel & the 5" vise is not even maxed out.




Here's what a 6" vise looks like on another PM45 (gt40's)
View attachment 253544


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## Ianagos (Feb 8, 2017)

Oh ok you could remove tail stock and slide the carriage that way then put a steady rest on. I feel like you'd barely make it but you said you had 40" of bed so it can prob happen. I just think especially for the reamer a nice feed will help with finish.


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## brasssmanget (Feb 8, 2017)

OK I'll look at that possibility tomorrow. Just got the second drill bit today so I'll be switching gears to the bore work very soon. Thanks for the reply and suggestions.


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## Ianagos (Feb 8, 2017)

No problem like I said in my first post maybe try a copper line with air blast to get the chips out. Let me know how it turns out. I'd like to do the same thing but I haven't found a piece of steel big enough for cheap enough. My lathe should be capable of you can do it.


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## brasssmanget (Feb 24, 2017)

A 6" vise is overkill for a RF45 style mill. A 4" is more appropiate for that size mill & IMO 5" max. I have a 5" GMT vise on my PM45 & it's slightly too big. Not enough Y axis travel to make use of the 5" full capacity. Better to save your money rather than getting something too big & most importantly the weight. I take my vise of the table quite often, a 6" is still light enough for me to be carried by hand but I'm glad I have a 5". I also have a 4" vise as well. I prefer the 5" though.

But those GMT 6" Premium vises are pretty nice. I'd love to have one but don't need one on my current mill. But if you plan on upgrading to a full size knee mill in the future than the 6" will be perfect.


Here's what the 5" looks like on my mill.




I couldn't even complete this cut without my bellows & DRO scale getting in the way. Not enough Y travel & the 5" vise is not even maxed out.




Here's what a 6" vise looks like on another PM45 (gt40's)
View attachment 253544


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## Silverbullet (Feb 24, 2017)

Nothing funny when you look at what you made from your mock up. Looks like you've done a good job of machining and the finish on everything says HEY I'm a real Canon don't mess with me. Watching for it all finished and ready to fire. If your going to fire the Canon be sure to proof it safely .


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## brasssmanget (Mar 2, 2017)

A 6" vise is overkill for a RF45 style mill. A 4" is more appropiate for that size mill & IMO 5" max. I have a 5" GMT vise on my PM45 & it's slightly too big. Not enough Y axis travel to make use of the 5" full capacity. Better to save your money rather than getting something too big & most importantly the weight. I take my vise of the table quite often, a 6" is still light enough for me to be carried by hand but I'm glad I have a 5". I also have a 4" vise as well. I prefer the 5" though.

But those GMT 6" Premium vises are pretty nice. I'd love to have one but don't need one on my current mill. But if you plan on upgrading to a full size knee mill in the future than the 6" will be perfect.


Here's what the 5" looks like on my mill.




I couldn't even complete this cut without my bellows & DRO scale getting in the way. Not enough Y travel & the 5" vise is not even maxed out.




Here's what a 6" vise looks like on another PM45 (gt40's)
View attachment 253544


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## markba633csi (Mar 2, 2017)

I was scratching my head because I knew you were making a steel cannon but in the pix it looked like brass- looks like your camera gives a reddish cast so that explains it. 
Are you going to use Pyrodex powder to fire it? It's sulfurless so it wouldn't be as corrosive to the steel. 
Mark S.


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## brasssmanget (Mar 2, 2017)

I'll probably use BP first for the flame effect, and then use a BP substitute after that to save on corrosion........IF I ever get to that point. [chuckle]


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## markba633csi (Mar 2, 2017)

Can you get BP anymore? Here in Calif. (the nanny state) they don't let us have anything good.  Party poppers.  Ugg. 
Mark S.


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## Ianagos (Mar 2, 2017)

How did you end up finishing the bore? And I recommend black powder all the time just wash it out with the water hose after use.


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## brasssmanget (Mar 3, 2017)

Ianagos said:


> How did you end up finishing the bore? And I recommend black powder all the time just wash it out with the water hose after use.



I finished it up using a 1.25" reamer a fellow member let me use. Also opened the first 2" (at the bore end) to 1.50" - kind of a "back bore" for aesthetics.  No definite plans on BP, PD, T7, or what I'll use for the most part. Depends on price and availability I guess. I've dealt with corrosive cartridges for a long time shooting surplus WWII ammo in some guns, so no fear of that here....just simpler to use a substitute...


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## gjmontll (Mar 3, 2017)

Beautiful job on the barrel, then you say...
       Next I'll tackle the wheels....I have never attempted anything like that before, so I have no idea how they will turn out.
[/QUOTE]

I've been working on my own cannon project, and one of the first things I tackled was the wheels. I haven't posted anything on my efforts in about a year. But you mind find some useful ideas in my posts, see "Greg's French 75 mm Field Artillery Model" thread. Most of the posts from Summer 2015 through January 2016 are related to building the axle, wheel hubs, felloes, spokes, "spoke shoes", and tires. Let me know if you have any other questions/comments.

I may be next working on the barrel for my gun, which is not intended to be a fireable piece. It will be about a 3/8" bore (1:8 scale of 75mm), and for authenticity, should be rifled with 20 lands. Yours is a smoothbore, right?

    Greg


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## Cadillac STS (Mar 4, 2017)

Don't forget to post pictures or video of it firing!


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## brasssmanget (Mar 4, 2017)

Thanks GJ - I'll be sure and check out that thread/post........

I'll definitely post pics of firing [unless the unimaginable happens and I'm not inclined to show it]


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## brasssmanget (Apr 2, 2017)

Just an update on my progress. Been very busy with family stuff and a three week stint on jury duty, so things slowed down here for awhile. I did decide to make some wheels for the carriage, and I am now waiting for some flat stock for the outside wheel metal work. Thought I'd post a few pics of the progression to this point....


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