Author Topic: Looooong Range Shooting (Read 836 times)

Will Bison · « **on:** April 12, 2005, 08:44:14 AM »

Whilst sitting around the house waiting for the last vestiges of Winter to pass, I got thinking about a project. I and a few other cannon shooters are planning a trip to the 40 Mile Desert and do some extreme long range shooting. The playa extends for many miles and is as flat as a desk top.

Our plan is to fire the guns starting at 0 degrees elevation and then increase one degree at a time to establish some rough range tables. We hope that the surface of the dry lake bed will throw up a good puff of dust when the shot hits the ground. I'll be taking some GPS units and other surveying gear along.

This is a project I've been wanting to do for quite a few years and now it looks like all of us have the time to go do it.

We will report our results at a later date.

CAV Trooper · « **Reply #1 on:** April 12, 2005, 11:58:30 AM »

Will,

Sounds like you have your work cut out for you. Sounds like fun too. Looking forward to your results and a bunch of pics.

Cat Whisperer · « **Reply #2 on:** April 12, 2005, 12:18:26 PM »

Will -

Document it well. It will be interesting to compare your results with the theoretical trajectory tables.

I assume you're going to use spheres. It would be cool if you could also measure muzzle velocity and wind direction and speed.

When I was in the field artillary, we had the weights of each round noted and figured in such things as the elevations of gun site and target (as well as elevation from level of the tubes) and worked in the wind speed/direction at each 500 foot level, AND the direction - to figure in the effect of the rotation of the earth!

Even if you only measure a few of these things, documenting much will help later in sorting out the data.

Time of flight is also a factor to note.

Will Bison · « **Reply #3 on:** April 12, 2005, 04:22:27 PM »

I am very interested in some of the variables and they are many. The initial plan is to predict the fall of shot with Ingalls Tables. I've made some guestimates and it'll be interesting to see how close I get. I hope to eliminate as many variables as possible.

We are going to limit our shooting to spherical lead shot and a constant powder charge. All the shot will be weighed, measured for diameter and cast from the same batch of lead. That will be a lot of shooting at one degree increments. One of the guns will elevate to 27 degrees and the other to 19. Will also weigh the charges instead of the usual powder measure.

Air temp I can't fix and it will vary from about 40 in the morning to a high of around 90. We will record the ambient temp, pressure altitude and density altitude. Wind will throw a big kink in things so we hope to shoot in the morning. The dates are set at June 5-7, that gives us a full moon. We may be able to shoot at night in calm air.

On the longer shots we hope to be able to measure the angle of fall. Preliminary experiments show that the balls will penetrate about 6-8 inches in the lake bed. At shallow angles of impact as we all know, they like to skip and keep going and going and going............

Got to figure out how to keep from blowing my F1 chrony to bits. I've not come up with a solution yet. The problems are muzzle blast and smoke over the screens. Any ideas?

If any of you have some ideas of things we should measure or experiment with, toss 'em out.

http://www.lostoutdoors.com/map.php?map=39.933523,-118.314304&t=1&z=4&s=2&id=&mark=39.933523,-118.314304,255,0,255,7,Carson%20Sink*

If the above link works you can see an image of the "picturesque" terrain as it looks from outer space.

Bill

GGaskill · « **Reply #4 on:** April 12, 2005, 06:00:55 PM »

When you said "40 Mile Desert," I thought you might be referring to the Black Rock Desert (where the Burning Man get togethers occur), but I see it is not the same place.

Regarding your chronograph, I would make a couple of wood shields three or four feet square, with holes maybe twice shot diameter (maybe bigger depending on group quality) and place them in front of the barrel. First one maybe 5 feet in front and second 5 feet farther, with the Chrony just downrange from the second shield. Use sturdy supports for all as the muzzle blast will try to knock the shields over, especially the first one. You may also need a V-shaped deflector over the Chrony (point toward muzzle, space between the legs over the chronograph screens) to split the smoke at the chronograph.

I know, just what you needed, more junk to take with you. (-:

Will Bison · « **Reply #5 on:** April 13, 2005, 06:20:01 AM »

George I think you may have offered the solution. I was watching some aircraft carrier launches last night on TV and watched that blast fence pop up. We will give that idea a try prior to going to the desert.

We thought about the Black Rock but with the bad PR from Burning Man, the amatuer rocket guys and the partial closure of the desert, the Carson Sink (40 Mile) just seems better.

Bill

Cat Whisperer · « **Reply #6 on:** April 13, 2005, 11:18:28 AM »

A blast shield certainly is a good idea.

I remember measuring powder temperature too. A change in temp would make a change in velocity. Picky, picky picky.

GGaskill · « **Reply #7 on:** April 13, 2005, 11:34:54 AM »

Isn't the Sink more like a swamp than a desert?

Will Bison · « **Reply #8 on:** April 14, 2005, 04:14:25 AM »

Yea the sink is wet on the South end just North of Fallon. We'll be going about 30 miles north near the Navy bombing range. What's left of the Carson River flows into the South end and is a National Wildlife Refuge. The upper end looks like the Bonneville Salt Flats and is perfect for what we want to do.