Author Topic: 5" seamless schedule 80 bowling pin mortar (Read 1135 times)

bloomautomatic · « **on:** April 05, 2006, 06:15:00 AM »

I still haven't finished the .177 mini mortar, but I'm in the planning stages for the bowling pin mortar.

A standard bowling pin is 4.766" at it's widest point, 15" length and weighs between 3lbs 6oz and 3'bs 10oz.
5" schedule 80 pipe is 5.563" OD with a 4.813' ID - 0.375" wall thickness.

Does this seem substantial enough wall thickness for this project? Goal is to launch a pin about a 100yds at a pretty high angle.

I also considered setting it up for propane/oxygen instead of BP.

Vince

Double D · « **Reply #1 on:** April 05, 2006, 06:35:49 AM »

Maybe Vince, maybe not,

One of the others who is more knowledgable can correct me but you say schedule 80 pipe. I believe that is as welded pipe and you want tube not pipe, seamless, seamless tube. Pipe and tube are two different things.

Sinc this is a morter you need to tell us about you breech plug and the diameter of your powder chamber.

Also tell us which pre 1898 mortar you are going to replicate.

bloomautomatic · « **Reply #2 on:** April 05, 2006, 10:50:58 AM »

Not sure what I'm going to build it as. My main concern is finding a tube that is the proper size with no machining. I can bore some large diameter stuff, but not as deep as I'd need to for the pin mortar. If I can't find a readily available tube, that pretty much ends the project for me.

From what I read about sch 80 stuff, there is seamless and welded. I called one of the local supply houses and they gave me a quote for 5" schedule 80 exact seamless. The exact means that it's not extra heavy wall schedule 80. ($19/ft, 21ft length in case anyone was wondering).

Vince

Cat_Whisperer · « **Reply #3 on:** April 05, 2006, 11:52:42 AM »

Quote from: bloomautomatic

I still haven't finished the .177 mini mortar, but I'm in the planning stages for the bowling pin mortar.

A standard bowling pin is 4.766" at it's widest point, 15" length and weighs between 3lbs 6oz and 3'bs 10oz.
5" schedule 80 pipe is 5.563" OD with a 4.813' ID - 0.375" wall thickness.

Does this seem substantial enough wall thickness for this project? Goal is to launch a pin about a 100yds at a pretty high angle.

I also considered setting it up for propane/oxygen instead of BP.

Vince

Vince -

You've given only a few details and are looking for the answer. To answer 'is it strong enough' is dependant on DESIGN - powder chamber, interior contours and wall thickness of bore (among other things); material - type, hardness, strenghts (several come to mind); and proper loading - charge and projo. You're likely to be in the right ballpark, if the other issues are addressed reasonably.

Once you mention anything other than blackpowder or pre 1899 design it would be good to ask questions elsewhere. I thoroughly enjoy the projects, but we've placed limits on the content of this board for our (and others') protection.

Kuntrykouple · « **Reply #4 on:** April 06, 2006, 05:11:55 AM »

vince, instead of the schedule 80 try calling around to a few feb shops and metal dealers and look for a drop of whats commonly known here as mechanical tubing (no weld) it can be bought with about any wall thickness you are wanting, around the legnth you need. now just a warning the mech tube is quite a bit higher round here tis about 2.75-3$ a pound.