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What to make for 30-40m range accuracy with tennis ball

Posted: Thu Nov 13, 2008 6:33 am
by urbanfarm
I have been looking at some of the designs to fire a tennis or golf ball a few hundred metres and some designers mention recoil.
However I never see a well designed linear shoulder stock, even the one on Mr crowleys Pneumatic Golfball Cannon- Shoots 450+ yards! would result in poorer accuracy as I would assume there would be flex in that design, or am I wrong?

I am looking at that design quite seriously to mod it with a linear from barrel stock, is this wise or am just a newb who worries too much?

Am planning to run tennis balls or maybe some sort of shot arrangement targets are generally within 30m and I would desire some decent hitting power and accuracy

is this feasable or is there a better way?

Posted: Thu Nov 13, 2008 6:38 am
by VH_man
sigh....

Discussion of firing your cannons at any living thing is porhibited here. I suggest you read the rules.

Second, I shoudl really drop it, but Hunting with.. Golfballs? Vermin? Your gonna have the fish and game tearing your head off.

Cannons like Mr. Crowleys golfball cannon are about as accurate and powerful as your going to get......

Re: What to make for 30m range vermin eradication?

Posted: Thu Nov 13, 2008 7:19 am
by Ragnarok
VH_man has already made the point about the rules, but...
Plan to mainly use it for vermin targets up to 30m away and hoping for better than 30cm accuracy
What? Do you have some kind of super vermin around there? If you think 30 cm accuracy is sufficient, you're sorely mistaken. For humane vermin control, think more like 3 cm accuracy... AT THE VERY OUTSIDE.
Also... golf balls? Good vermin ammo? No, just no.

If you have to deal with vermin, get your hands on an air rifle, not a spudgun. Put it this way - my spudguns are dozens of times more powerful than my air rifle, but you don't see me doing pest control with the spudguns.
This is because spudguns do not have the accuracy (and often the terminal effectiveness) to be humane.

~~~~~

On to the rule legal point... shoulder stocks. Take a look at my HEAL: http://www.spudfiles.com/forums/topic-t11453.html
That was deliberately designed so the QEV at the back fitted firmly into the shoulder like a stock butt - it should be clear if you watch the video.
With the porting attachment (not shown in any of the photos), HEAL is reasonably accurate.

However, the butt of a stock isn't actually involved in controlling any of the recoil to improve single shot accuracy. Yes - it controls the recoil, and yes, it helps improve accuracy... but the two matters are not linked. The accuracy improves because the stock makes it easier to aim the rifle well, not because it controls recoil.

Even with a slow lock time, high recoil "gun" like a spudgun, this isn't the case - the lock time is still far too short for the stock to have any impact at all, as humans are elastic. In other words, the rifle/whatever has to have recoiled some distance before we actually start absorbing that recoil energy. Given the relative masses (and therefore velocities) of the launcher and projectile, the bullet is long gone before the rifle has recoiled enough for you to absorb that. Recoil is felt long after the bullet has left the muzzle and thus after it can still be affected by it.

A straight stock helps control where the recoil goes and how it affects the rifle's point of aim after the bullet is long gone. As such, it is beneficial for the full-auto accuracy of automatic weapons like the M16, but for a single shot rifle or launcher, essentially irrelevant.

Posted: Thu Nov 13, 2008 7:23 am
by jackssmirkingrevenge
Legal issues of shooting living things aside, spudguns are more akin to shotguns than rifles by virtue of their smoothbore barrels, in order to reliably hit small targets at anything other than a few feet away, you're best off making a large calibre launcher and loading it with multiple projectiles.

Posted: Thu Nov 13, 2008 7:57 am
by Demon
you're best off making a large calibre launcher and loading it with multiple projectiles.
A chick peas shotgun at very high pressure should work.

But why are you posting those question on spudfiles?Check the rules.

Posted: Thu Nov 13, 2008 8:22 am
by Ragnarok
Demon wrote:A chick peas shotgun at very high pressure should work.
Nowhere near the terminal effectiveness and sectional density to be humane. I'd use no less than .177 BBs if I absolutely HAD to do such a thing.