SpudFiles

jackssmirkingrevenge wrote:Now you'd talking - they're even a better ballistic shape than a sphere so will lose less velocity to drag as they fly along, I think that 0.1g loss is worthwhile

if only they made them in .25g or .30g

Do you actually intend to use this for airsoft or general plinking, and what ranges did you have in mind?

well general plinking but i want to get the most out of my 6mm sniper when i make it, i just want to make it shoot as far, fast and as accurate as possible and i think for a smooth bore with no hop-up the airfins are ideal even though they are a little light.

Realistically I'd say that you'd be limited to about 30 yards maximum for small targets like soda cans. A scope would certainly be helpful, as well as some calibration to find out how much the projectile drops over distance so you'll know how much you need to compensate for ranges other than your zeroed distance.

what kind of range would i get with a hopped up .35g bb?

What kind of accuracy are you expecting? In the hands of an average marksman, a commercial 12 ft/lb air rifle is normally used for a maximum of 45 yards or so for hunting, the standard for hunting being the ability to consistently hit a 1 inch circle.

In this case your velocities will be somewhere between a 0.177 and an 0.22 air rifle, but your projectile is as wide as 0.25 pellet but weighs less than a 0.177 one, meaning you have a poor ballistic coefficient. This means the projectile will lose velocity quicker and consequently the drop will be more pronounced. hop-up is meant to alleviate this problem, but with no means of adjusting it, the chances are that it will hinder as opposed to help accuracy. For that 1" circle target, with BBs 30 yards is probably the best you'll get in any situation.

i think i will probably use hop-up and a .35g or .43g teflon coated bb, i could probably use .22 air rifle pellets with a sabot because there is only a 0.5mm difference between the pellet and barrel, or i could mold my own ammo like the "pimpin ammo" and get a heavy pellet or i could take a mold for the airfin and fill it with something denser.

and how far can commercial airsoft snipers shoot? they only use 400-500fps usually so i should be able to get better range with good hop-up, shouldn't i?

and i found this page http://arniesairsoft.co.uk/?filnavn=/ar ... .htm#range which allows you to calculate the effective range of your airsoft gun. it says if i use a .36g i will get a muzzle energy of 10.56 joules at 800fps and an effective range of ~106m obviously this doesn't take into account environmental influences or hop-up, and i'm not sure how accurate it is but 350ft is a long way...[/url]

an effective range of ~106m

In terms of airsoft snipers, "effective range" is the distance at which you can hit a person, hardly a small target.

As to adapting airgun pellets, have a look here

As to adapting airgun pellets, have a look here

genius!

and the effective range is how far it will travell from being shot 1m above the ground before it hits the ground so i think with hop-up and a scope i can compinsate for the dip and hit a reasonably small target, my aim is to hit a person sized target at 100ft is this realistic?

My paintball gun has hop-up. I put a nylon string down the top of the inside of the barrel and it gives me an extra 30 yards. I put a rubber band on my step dad's Tipmann (5 inch barrel) and it worked just as well.

LeprechaunIV wrote:My paintball gun has hop-up. I put a nylon string down the top of the inside of the barrel and it gives me an extra 30 yards. I put a rubber band on my step dad's Tipmann (5 inch barrel) and it worked just as well.

thanks for the tip but it might be a bit hard lining up the string down an 80cm barrel.

You will find that a string lines up pretty good under tension. That's how chalk lines work....

Hawkeye wrote:You will find that a string lines up pretty good under tension. That's how chalk lines work....

hmm i suppose, but using that method it would be hard to get the right amount of hop-up.

You could just use a variety of thicknesses of string(spider wire fishing line?) until you hit the right one. How far it runs down the barrel could be experimented with as well. Paintball barrel material isn't very expensive.

Hawkeye wrote:You could just use a variety of thicknesses of string(spider wire fishing line?) until you hit the right one. How far it runs down the barrel could be experimented with as well. Paintball barrel material isn't very expensive.

yes but this is not for paintball, its for a 6mm airsoft 'sniper' and my barrel is a very tight bore so it could be difficult. i will give it a go when i finish my 'sniper'