bowling ball question

[dirtdobber1919a4]

i have finally got a tank the correct size for a bowling ball mortar.  ive just about finished the bas plate. but im still very unsure on chamber design.  several questions.  how thick does the wall of the sub chamber need to be to be safe, planning on at most 1000 grain shots. after the chamber has been fabed up, how do i install it into the tank without making the the tank weaker itself?

[Double D]

Pre 1899 mortars don't have base plates!

If you are building a mortar with a base plate you will need to take your question to a board that deals in post 1898 mortars, that is unless you can provide us with a letter from ATF saying your mortar design is considered an antique.  That is the ruiles of this board.

If you build a post 1898 mortar without a letter from ATF permitting the build you may be subject to enforcement action by that agency.

In that light, absent a letter from ATF saying your mortar is classed as an antique, this board cannot be used to aid or abet you in your build.

Get that letter and you will get tons of help from the folks here.  Or build a pre 1899 mortar and we will be more than glad to help..

[RocklockI]

It could be a misunderstanding of terms here ?

Or it coulb be an internal barrel inside a shroud ?

[Double D]

Lets hope you are correct.  But base plate and breech plug do have different meanings.

Dirtdobber if this is the ttype of mortar you are building you will need a letter from ATF saying it is an antique before you can post it here.



If it is a mortar like this one, then post away!