Thundermug load question

[morehops]

I was looking for a boomer last year and based on suggestions that I got here I bought a thunder mug instead of a mortar. Tried it first at 100gr FF. Just got a big THUT. Then went to around 200 gr and I knew i was getting there. The last load was at somewhere around 250-300 gr and man was that LOUD! Used a newspaper wad on top of the powder.
Afterwards, IIRC I saw a post that for cannons, that the rule of thumb is wall thickness equals or excedes the bore diam. That is for shooting projectiles. I have a 1" bore and wall thickness of 0.25". The tube is made of 1144 steel with a heavy steel base. It feels very substantial but I want to make sure that I'm being safe. I NEVER intend to shoot any kind of projectile out of this thing, just make noise. If you have some experience with this type of ear blaster can you recommend a (safe) upper limit of powder charge? Also, I use FF because F is very hard to find here.

 

Am I the only one here that is as nervous as a canary at a cat show???

 

[RocklockI]

The barrel walls are too thin, what if someone in the future DOES shoot a projectile ? with a bunch of smokless powder?
JMHO

Good Luck Gary

 

[freekforge]

it depends how many cats attended your cat show?

 

[morehops]

Ok I get it. I got sold a bill of goods. So is there a recommended bore to wall thickness ratio for a thunder mug, or is it the same as for a cannon bore? BTW, was my memory correct as to bore = wall thickness?

 

Rule of three works for me! Original Thunder Mugs were mostly chambers from breech loading cannons that were repurposed.

BTW, Happy Birthday!

 

[freekforge]

Yep you were right 1in bore 1in walls 3in diameter or replace the 1 with another number I just don't feel like doing any math :haha: