Fingers284, no problem man and thanks i was pleased with the outcome. A few guys at work told me not to be surprized if the drill started coming out of the side of the round bar before it makes it to the end. Lucky for my it worked well. It still alowed me to have a 4.5mm wall at the muzzle.
Rayleigh, interesting. Thanks for the warning. My breach plug seals at the end of it. The bore is 22mm and the end of the breach plug is 25mm and there is a 0.010 gap at the back when threaded in tight so i know its sealing on the face and the threads are not exposed to the pressures/gasses. But after the proof loads i do plan on measuring barrel swell in a few places and checking the back and forth movment of the threads.
The tenth pic in the first post shows the seal face inside of the barrel
My load i want to shot is 250gr black powder using a 1000gr cloth patched lead ball, im going to proof it with 350gr of FFG. And fire 5 proofing loads via a string.
I may be overstepping my bounds here and don't want to offend in any way but I am very interested in how much experience you have had with large BP charges and if I may I would like to relay my experiences using that much powder. I don't think I would ever relish the chance to pull the trigger on even a 15 lb rifle with 250 gr of black pushing a 1000 gr ball LOL
I have two cannons ( 3 actually, 2 tubes fit one carriage) that I will load with anywhere from 300 gr of 1F for the 1/2 scale (1.624 bore) to 3 oz for the full size 2.624 bore. I will key on the 1.6 bore ones as they are closer to your project.
Both of my smaller tubes are 36" long and have a min of .500 wall thickness from end to end, as well both have a .500 wall thickness "collar" at the breech end for a length of 8 " or so ( total wall thickness is 1.00 at breech), as you can see they are considerably beefier than your barrel. All the time I was building mine I had it in my mind that I was being my usual "farmer builder-over cautious self" and maybe I was but my guns are fire a lot with 40 or 50 spectators around all the time so after firing those guns personally I am glad I was overbuilding them.
Now for the brass tacks of firing 300 gr of black. I have two different rounds I use in them, one, just a noise maker -blank round and a 15 oz. round steel ball "projectile round". The blank round is still 300 gr of powder but it is only a 3 layer cylinder of Aluminum foil long enough to hold the powder charge, no projectile or wadding of any kind is used and believe me the sound effect is sufficient to get everybody's attention. The muzzle flash/fire from this round easily extends 15-20 ft from muzzle and smoke is almost twice as far.
The projectile round (closer to what you are describing to use) impressed me to no end as to it ferocity upon firing and equal downrange destruction. Of course the 15 oz ball I use is much heavier than you will use but bear with me as the powder charges are not that much different. I have tried this 300 gr/ 15 oz steel ball load in energy tests 3 different times. The first was at a 1/2 sheet of 1/4 mild steel plate leaning loosely against a 2x4 prop-up (no pressure on it from the back, just its own weight as resistance) from about 40 yrds. That 1/2 sheet of steel violently cartwheeled backward a ful 360 deg and then some when it was hit. the steel ball almost went completely through the plate, if the plate would have been solidly anchored I think it would have.
The second testing was with 24" long green cut logs about 14" in dia. The steel ball wouldn't completely travel the full 24 " but very close to it...the logs would be split in 3 or 4 pieces from end to end.
The third test was a hit on a 1/4" thick 48" "tempered steel" lumber mill saw blade at 100 yards, again an almost full perforation (this time the steel blade had some backing from a stand)...enough to dent 2/3 the size of the ball and break the steel open behind the hit.
Two more point I want to convey and then I will get off my "soap box".
The recoil of my little cannons are one thing that concerns me about your plans. My little guns weigh in around 80 lbs. with the carriage and with the carnage trail just laying on the ground, with the blank round it will roll back a foot and with the projectile load it will easily recoil 3 ft.
The last point is that I have chrono'd the 15 oz. projectile round twice and got a reading of 1350 fps ( someone on this forum informed me that that equals somewhere in the 26,000 ft lb. of energy...3 time that of a .458 win mag) ...again, your projectile is considerably less in weight but with your suggested powder charge firing a 15 lb hand held gun wouldn't be on my "bucket list".
Again I apologize if you take this offensively...not my intension at all...just that if your not used to it - 250-300 gr of blk is very much more violent than a regular 100 gr muzzleloader charge.
