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ball bearings
Posted: Mon Nov 19, 2007 1:47 pm
by POLAND_SPUD
I am planing to use 1/2" or 12mm ball bearings as ammo. I know one place that have them in almost any posible size and quite cheap as well.
1.My question is... Has any one tried using them as ammo, with what results?
2.Does the magnus effect noticably affects their accuracy?
3.Would a few cm's of insultion tape placed inside the upper part of the barrel would be enought to induce spin on balls ?
( also post if you have ever made a hop-up on spudgun )
feel free to write anything you think is important/relevant/interesting
Posted: Mon Nov 19, 2007 2:22 pm
by Ragnarok
1) Yes, many people have use steel ball bearings as ammo, and the 12.7mm or 1/2" size is probably the most popular.
I usually use 3/4" size - they make big holes, fly quite well, but won't perform as well as a dart at either.
2) The magnus effect should have a very noticeable effect on range, and should improve accuracy as well, but to what extent depends on spin rates.
3) I don't think so, I don't think it would have the right grip.
I created a very brutal hop for my last cannon that gave a very pronounced spin to the projectiles, and if I ever got the chance to use it on HEAL, it would probably put a ball bearing a mile - well, that's an exaggeration, but it should go at least half that.
That was only a mixed of "sculpted" copper and rubber sheet that sat at the muzzle, although I'm not sure I have a photo of it...
Posted: Mon Nov 19, 2007 2:26 pm
by mega_swordman
1. Yes, people have indeed used them before and they work great for the use of puncturing objects.
2. I'm not sure.
3. I don't think so; if anything I think it would slow down the ball bearing, thus causing a loss of power and possibly a drop in accuracy.
EDIT: Drat! I've been out-drawn.
Posted: Mon Nov 19, 2007 3:17 pm
by POLAND_SPUD
I was planing to put my hop-up in the breech (not in the muzzle part of the barrel) - so that it would start spinning form the very begining.
I am just guessing - if my barrel has ID of 12.7 mm, balls have 12 mm, a 0.1 - 0.3 mm thick and 10 cm long piece of insulation tape placed on the upper inside surface of the barrel should induce spin on balls... well, at least theoreticly right ?
the only problem would be the consistency or am I missing something else ?
Ragnarok - I've just found something... 3/4" balls weight about 28 gramms - that's ~ 3.5 times more than 1/2" ones (8.5 gramm)
- what muzzle velocity do you get with them...?
http://www.gewa.com.pl/page.php?d=kulki1wymiary <-- you might find it usefull - a page in polish showing weight and size of steel ball bearings (before u ask.. no... you don't need to speak polish at all to read the table
)
Posted: Mon Nov 19, 2007 3:36 pm
by jackssmirkingrevenge
Ball bearings rock, here's what a 0.5" ball bearing did when
fired from my 3/4" piston launcher
I still want to make a pneumatic big enough to fire
this one
Posted: Mon Nov 19, 2007 4:27 pm
by Los Frijoles
jackssmirkingrevenge wrote:I still want to make a pneumatic big enough to fire
this one
Is that a bowling ball or its smaller, heavier cousin?
Posted: Mon Nov 19, 2007 4:27 pm
by Maniac
Posted: Mon Nov 19, 2007 4:48 pm
by DYI
Jack, how much does that thing weigh? It looks like a shotput ball, but bigger. I could fire something that size from the SCTBDC, but it probably wouldn't go much over 200 fps by the looks of it.
Posted: Mon Nov 19, 2007 4:53 pm
by Ragnarok
It's part of a crane's summat or other, and weighs in at 1.4 kg if I remember right from the last time JSR lamented his lack of a 3" pneumatic.
Posted: Mon Nov 19, 2007 4:57 pm
by DYI
It seems as though the SCTBDC could get that going about 340 fps. I should try to get some of those. I'd ask JSR to send it to me, but I don't know how the overseas shipping on it would be. Of course, 1.4kg isn't that heavy.
Posted: Mon Nov 19, 2007 4:59 pm
by Maniac
yea that thing would be a beast to fire would do some extreme damage
Posted: Mon Nov 19, 2007 5:10 pm
by psycix
1.4 kgs going 340 fps!?
Man that cannonball will go through everything!
just insane!
I mean like.... everything! cars, trees, walls, tanks, concrete bunkers, it just bashes through!
Posted: Mon Nov 19, 2007 5:45 pm
by windshrike
I officially prohibit JSR or DYI from shooting that cannonball without videotaping it. At 1.4 kgs, the energy retention would be amazing, it would fly for a LONG time. In my opinion, it should be shot at a solid block of ice.
Posted: Mon Nov 19, 2007 6:01 pm
by DYI
The only problem is that JSR doesn't have a big enough gun, and I don't have the ball bearing. That would need to be a really big chunk of ice to stop it though.
Posted: Mon Nov 19, 2007 6:14 pm
by windshrike
JSR hasn't said that he
wouldn't send it to you, DYI. I don't think that he will, but, on second thought, perhaps FEAR would be a more appropriate solution to the massive ball-bearing problem. And I never said anything about the ice stopping it.