Relationship between bore diameter and length

[Cat Whisperer]

The length of the bore can be expressed as a ratio of how many bullet diameters long it is.

Let me compare the effect.  My 'beer-can' caliber mortar has a bore length of about 2 or so diameters.  A sand filled can will go at most about 130 meters.  My friend's 'beer-can' caliber mortar is 3' long.  He can chuck a 1/2 length can filled with concrete about 400 meters with about 100 GRAINS of powder, where I'm using about an ounce to go 130 meters.

So the question is two-fold - on the one hand you can have a highly portable machine with short range and loud report, or you can have a much larger device with longer range and the familiar 'thunk' of a mortar.

[Double D]

FWIW the range of the old blackpowder mortar was determined less by elevation and more by powder charge weight. Humm now that I think about so are modern mortars.

I see a future need for field testing to establish range tables for different charge weights in our mortars.  


I can just see it now...the banner on Handloader Magazine reads Shoot out! GOEX vs ELEPHANT in your Beercan Mortar! or Bud vs Diet Coke, which can  for you beercan mortar?  Man, I think I might be staying up too late at night...how about Ballistic tip beer cans...no, no, no.

[JeffG]

How about tracer bowling balls??? :-D  :-D

[Cat Whisperer]

Tracer Bowling Balls -

  We've already seen some people on this board that tie colorfull tape to their projo's and those that put 100 yds of streamers to the same, now tracers.  Maybe if painted with luminous paint and fired at night....

And another with a fuze and smoke bomb to go off down range....

I'd often thought of a switch that would turn on when inverted - and trailing rope that would turn the round upside down when at the top of the trajectory (mostly up) exploding the smoke charge up in the air.

[JeffG]

I wonder if you could get a shortened road flare to ignite from main charge blow-by, if you put it in the finger hole??