New to board - building semi recoiless GB cannon

[CNC Shop]

3" OD - 1.75" ID breach lug welded and cross pinned. Mounted on two NSK linear slides. I will be attaching gas springs (hatchback type) to absorbe the recoil. I have up to 5" of travel in the slides. It will have a rail on top with a red dot and some kind of T&E mechanism. I know it's about as bastardized of a cannon as you can get. I have a nose up nose down aircraft instrument that reads in degrees that I may mount to it along with an analog G force meter.

Comments / ideas?

KW

[Double D]

What pre 1899 cannon are you building?

Also to meet the safety standards we recommend a 1.75 bore needs 5.25 OD.

[Cat Whisperer]

CNC shop -

WELCOME to the board!

What Douglas is asking refers to our limiting posts to cannons/mortars etc that were made (or replicas) pre 1898. 

[CNC Shop]

Not sure i get it but it sounds like I am posting in the wrong forum / board. I am building a pre 2011 replica out of 4130 chrome moly based on the strange ideas from my twisted mind!

KW

[Cat Whisperer]

That sounds right.  But it does sound like a fun project.  Might even be able to measure some things about recoil too.

[Double D]

Suggest before you build, since the bore is larger .50 cal that you submit your design to ATFE for a permit to build.  In the mean time since your build doesn't meet the requirements for the black powder cannon forum I will move you over to the Exotics board.

good luck.

[briarpatch]

I probably know more about the mating habits of t-rex than I do about cannons. With that said. Will 4 allen head bolts hold that thing under repeated recoil?
Looks fun and interesting.

[CNC Shop]

actually two more in the bottom but I understand the point. At this phase of prototyping I need to ne able to tear it all apart and start over.

KW

[Cat Whisperer]

I probably know more about the mating habits of t-rex than I do about cannons. With that said. Will 4 allen head bolts hold that thing under repeated recoil?
Looks fun and interesting.

It depends on the mass of the projo you shoot.  Rule of thumb for blackpowder cannons is that the diameter of the trunions is equal to the bore diameter.  If you're shooting golf balls (light weight) 3/4" will last, but if lead, aluminum, zinc or iron spheres of 1.7" dia. it's a different story.

[Double D]

Suggest before you build, since the bore is larger .50 cal that you submit your design to ATFE for a permit to build.  In the mean time since your build doesn't meet the requirements for the black powder cannon forum I will move you over to the Exotics board.

good luck.

I corrected my post above, I had the letters in the wrong order---keyboard has dyslexia. Don't know what AFTE is

It is ATFE-Alcohol Tobacco Firearms and Explosive is you should seek a permit from.