A gun smith I know found out that I have this hobby he asked what size of "shot" we use. He has a large supply that he was willing to sell me. I told him sorry we do not use lead for ammunition. Now if only I could get him to make rifled barrels......
Exactly what do you think rifled barrels would achieve? I have a feeling they wont meet your expectations.
I am not expecting to drive nails at 100 meters. But I would like to hit inside of a four inch circle at four feet.
Try using "tighter" barrels and make them as long as you are allowed/able. Using 5" stainless steel barrels drilled out to 0.177" shooting regular Daisy BBs (0.173" diameter) I can put rounds through a roughly dime size hole at about 2-3 feet, inside a 4" circle at 4 feet should be doable. I have similar barrels that are only 3" long and they have a much wider dispersion. I doubt you'll be able to engrave a steel projectile enough at the pressure ranges we use to put significant spin on the projectile. Even if you did the steel on steel would wear down the barrel fairly quick. Not to mention we shoot spherical projectiles.
I have heard a report on rifled barrels doing 1/2" groups at 6' range. Even tight tolerance barrels are not that good.
So you're engraving very small steel projectiles with ~150 psi? I don't buy that. On a 0.25" ball bearing thats ~7.36 lbf. For a standard BB its only ~3.69 lbf. Any rifled barrels you may have heard about probably shoot better because the rifling provides a tighter ID which produces the tighter groupings. But you dont need the rifling to get that. Rifling works by spinning a projectile to make it gryoscopically stable so it doesnt pitch and yaw. If a bullet pitches or yaws to much it will go unstable and start to tumble and then range and accuracy are out the window. If a sphere pitches or yaws its still a sphere flying through the air, it has the same stability as before. Plus you still need to engrave the projectile somehow to get the benefits of the rifling, I dont think our cannons have enough power to effectively do that. If you have data that shows otherwise I'd be very interested in seeing it, or BBs/ball bearings that have been engraved using the pressures we use in our systems. All the store bought "tight tolerence" barrels that Ive measured have the same ID as the regular barrels so there is no reason they would shoot signicantly better(they just have tighter tolerences to the same dimensions so there is less variation). However using a barrel with a tighter (smaller) ID will help you shoot harder/more accurate.
Boy! I did not realize what a reaction there would be! I had put that comment in there to liven things up. In all honesty, I had thought that rifling would not be possible because we are using steel balls in a steel tube!
What about (at least for BBs) ones that are plated in copper? I'd expect that as long as the plating is thick enough and the copper hasn't become work hardened, those should engrave to some extent?
With less than 4 lbs, realistically speaking I doubt it. At some level if you control the tolerances of the BB/barrel to crazy levels you might be able to see some micro scratching, would that be enough to spin it? Who knows, doesnt really matter either since it isn't realistic. The tolerences, especially of the brand of copper plated bbs that Ive seen in the hobby, aren't nearly good enough to be able to do that consistantly. Also if you were engraving the BB that takes a fair amount of energy which would mean your guns wouldn't shoot nearly as hard. So you wouldn't be shooting as hard and you still wouldn't be gaining anything from the rifling in terms of accuracy.
It seems like a lot of work for... FAIL! One stupid bb and it's all over. I have triples that can nail a 2 inch circle at 3-5 feet behind the boat and a whole bunch of people that can attest to that. I find more fluctuation with the bb path due to change in air pressure or burrs and the barrel ends. When they are firing well they are fairly consistant. I notice when I have a glitch and shoot the pin sometimes they cause a burr in the barrel end. I was shooting over people's ships due to that. (until I found and corrected it) Other than that, they can fire accurate.
Not knowing the gun system, is the problem 1/4 inch ball bearings are hard to keep on target? How much pressure is it fired at and how is the barrel/ breach designed. I think these things would factor into it the most. We are firing bb's at 150psi so I imagine the forces needed would have to be similiar.
By the way, I think that it is time we get back to the topic and get Ryan to meet with a club. Ryan; Have you been in contact with any of the clubs yet? Various clubs do have plans available for “active” club members, and are will to give a lot of help in building a ship. And even possibly parts!
As to the subject of clubs. Well, as far as a BG club,the ones around Maryland are the Chesapeake group and something in VA, i think! There is an active IRC club in the area and some treaty people. I have an open house work session every Friday night at my garage (see Maryland Attack Group for additional information). Building the boat is not too much different in each of the clubs really until you get to the point of arming them and the difference in speed. Marty Hayes
Don't forget about the thickness of Balsa. In Big guns it depends on the armor of the actual ship. The Balsa can be from 1/16th up to 1/8th of an inch thick!
Hey Ryan: Check out the For Sale forum. Under the heading of: Big Gun warships sale Sharnhorts class WW2 era German BC- Fiberglass hull, 3 main indiana style 7/32 cannon. Front 2 are linked to rotate, all 3 have depression. Ship has a 7 channel futaba radio installed. Sank on last battle years ago and never repaired. Superstructure in need of major work. The bad part is that he wants to sell everything! Maybe you can team up with someone, and split the cost and items.
Hey Ryan; I saw that he will not sell the items indivually. Have you become active with a club yet? Clubs normally sell ships to members at a discounted price! A few months ago I was made an offer that was almost too good to pass up. A ready to sail battleship, W/ four operational turrets, where all I had to do would to charge the batteries and put it in the water! I am still kicking my self in the pants for passing that up!
I am so stupid, I should have realised this earlier, you could get a bb to have a spinning effect WITHOUT rifleing. Airsoft guns use whats called "hop up". For anyone who doesnt know, at the end of the barrel inside the gun, there is a rubber sleeve. Some sort of adjustable arm pushes this down into the barrel so that when a bb is fired,the friction on the top makes it have a variable spinning effect. This has a Large effect on the guns accuracy, too high it flies up, to low it drops fast. perhaps i could post pics later? airsoft bbs are 6mm by the way. I think a few paintball barrels make use of this effect, one even useing it for shots around corners and over walls.
