Posted on 09/27/2003 8:39:41 PM PDT by mhking
Ah, serendipity. Being in the right place at the right time.
As it happened, this fine and sunny September Sunday morning found me and a few others at the local gun range, sighting in- or trying to- some rifles. Some were cooperating, some weren't. A normal outing to the range, really...
Until this fellow pulls up and starts unloading a big 'ol hunk o' pipe.
I thought he was going to bury it as a new target stand or something.... 'til I saw the Bowling Balls. I then immediately knew it must be what some call a "punt" mortar! I'd seen similar handmade ones on the 'net and in magazines... naturally, we all completely forgot about our own rifles for the moment.
The Gun Range is a nice place- raised, covered shooting line, plenty of tables, well-kept grounds. The first line of targets is at 100 yards, with small berms and pipe target stands at 200, 300 and 400 yards as well, plus a trail/road to drive up to 'em if you need to. And at 500 yards, right at the base of the stand of trees off in the distance, is a full-size steel cutout of a moose, painted day-glo orange. Above, the guy with the mortar is pouring in some three ounces of Fg (coarse) Pyrodex black powder...
This thing is huge! Probably weighing some 150 pounds, half-inch-nominal wall pipe with a massive two-inch-thick breechblock welded on one end. The touchhole or fuse passage leads to a small "chamber" in the center that holds the powder in a single spot, rather than letting it cover the whole 8.5" bore.
Crude, yes, but it works. The owner is reluctant to do any additional welding on the pipe, for fear of making a weak or brittle spot, so he just stacks up whatever's handy to hold it, oh, 'bout there or so. This thing's so cool I want to make the guy some adjustable legs like the old 4.2" Chemical Mortar had....
Three ounces of Pyrodex, an old garage-sale-special bowling ball, an old chair and some sewer pipe... Fire in the hole!
He's not running, but he ain't dawdling either! Let's see, the fuse burns at about one minute per foot, there's about six inches there... dum da dum... carry the three...
HOLY FREAKING BATTLESHIP MISSOURI! By the time the shutter snapped, the ball was, in relation to this picture on your screen, about six monitors up and climbing. It was whistling. I lost track of it since I was trying to get the picture, but the guys say it cleared the treeline by probably another hundred yards.
Let's do that AGAIN! Rod out the fuse hole, make sure there aren't any errant embers, pull the mortar up out of the divot it created, weigh out another charge of powder, another bowling ball... This time I was watching downrange with the camera pointing at the cannon... Holy Creeping God, ladies and gentlemen! That ball was screaming out of there! I'd wager it landed over 600 yards downrange.
I should have brought out my Radar Chrony. I'd guess that ball wasn't moving over 700 fps, possibly as low as 400 fps, but jeez, think of the mass! That ball's what, eight to ten pounds?!? What's the Hatcher's Index of a projectile weighing fifty-thousand grains moving at 400 fps? "Body armor" against this thing is eight feet of dirt over a concrete bunker!
Think Grandpas' old thirty-thirty is a kicker? How about a hundred-plus-pound gun that pushes itself into the dirt six to eight inches each time it goes off? This is not a shoulder arm.
After all four balls were expended, we helped load it back in the guy's car. I noted that there were some divots from earlier shoots... he said he gathers up old balls whenever he can find 'em, then when he has a few, on a nice day he'll come out and blow 'wm downrange. Says it always draws a crowd. I said "so there's already a few balls out there in the swamp, eh?"
"Oh, more than a few, yeah."
He says he also has a short cannon that takes small tomato-sauce cans and another mortar that takes soda cans. The soda cans, it seems, don't hold together well- the force of firing blows the can off the concrete fill, which then blows up in the air.
Besides, he says, NOTHING beats seeing that bowling ball howl downrange as far as the eye can see.
I agree. :) The pictures don't do this justice; this is something every Tinker or gadget freak should see in person at least once in their life.
Call me crazy, I won't deny it, but how does the idea of a FReeper homebuilt mortar contest sound?
We could all agree on a future deadline, and have weekly threads where progress pics, ideas and solutions could be posted.
As far as the actual competition, as I imagine all of us actually meeting up in one state would be prohibitive for some, a remote competition could be set-up. We would just have to work out a standard range distance, target radius, projectile and number of shots allowed.
Although putting the highest number of balls on target would determine the overall winner, we could also vote on "Best design" and "Best Engineered".
Let me know what y'all think. I'm interested, and suggest "The Georgia Loose Cannon Brigade" as the Jawja team moniker.
See #94.
ROFL!! ... OK ... We win!!! ;-)
We drilled our firing sequence until we could have done it in our sleep. I was usually the loader 'cause I'm small (at least I was small then) and quick! I would "search" the mortar with nothing but my left hand guiding the hook over the mouth - and when I inserted a shell I knelt beside the mortar and held it between my two palms, releasing it by spreading my hands out once it was guided into position. For the big ones, my number two held the guide line with the electrical leads. In all the photos we have, you can see that my center of gravity is WAY back from the mortar mouth (my facial expressions are a study!)
We always treated explosive ordnance with a heck of a lot of respect. And my husband (now a respectable 52 and father of a family) will grin and hold out his hands outspread: "STILL HAVE ALL TEN!"
How far can one toss a whitfaced hereford ....with a tail wind of course ???
Stay Safe !
No, that would make a real bomb.
H110 is a medium-fast burning smokeless ball propellant, as you probably know, and a pound of it would turn that pipe into high velocity shrapnel. I'm sure you know all that and were only kidding, but still, we don't want to give any kid a very bad idea.
OK, so I'm an old fogey scardy cat, but I'm still kicking and some of my more reckless former pals aint.
There was a tv show within the last year that showed a modern trebuche built in Scotland that was aimed at a stone wall built for the purpose. It was great though the aiming was a real problem.
And don't forget plenty of duct tape.......we can always use plenty of duct tape !
LMAO.........I love these threads !........Stay Safe or at least try !
Stay Safe .....let eaker light that sucker off !
Warning. This can become a disaster instantly. Not for casual weekenders. If one wants a safer hobby, offer to fly Rutan's SpaceShipOne on its first 100 km sub-orbital.
........I'm in ! As to ignition sources what do ya think about a simple spark plug. I use one of those in my potato cannon ....works great for gases and also have seen a simple rig for cannon that uses a 209 shotgun primer. Drill and tap a hole in the base and screw it in, cock, load and move to non business end of 100' of lanyard , pull and let er fly !
Stay Safe ! To be continued after this fiasco !
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