SpudFiles

I have designed an airsoft "sniper" (by means i want to shoot further then 50m accurately)

And i wanted to know from you experts what could i expect from
.40g BB and 500 fps with a 530 mm tightbore 6.04 barrel(20") .

BTW, the trigger is very easy to pull.
I will keep an update on my work on spudfiles.

That's almost 3.5 ft/lbs at the muzzle, you wouldn't want to hit anyone at close range.

A typical 0.22" 12 ft/lbs air rifle fires a projectile that's twice as heavy with a slightly smaller diameter at a faster velocity, and it's still a considerable challenge to hit a 4" diameter circle at 50 metres, especially if there's a bit of wind.

Hitting a man sized target is of course an easier proposition but you're shooting a slower projectile with a much worse ballistic coefficient, I wouldn't put my hopes up on consistent accuracy.

So is hitting a soda can at 20 meters with no wind reasonable?

That's almost 3.5 ft/lbs at the muzzle, you wouldn't want to hit anyone at close range.

Its not meant to shoot at humans, neither animals. Its just to compete with my friends store bought spring .177 that gets lame accuracy at 5 meters...

Is a 4x scope well enough?

EDIT:

BTW, the gun would be incorporating a special kind of inline valve that i have not seen anywhere here on spudfiles.

A soda can at 20 metres sounds feasible, a 4x scope is more than enough. Still, if you're going for long range accuracy without worrying about hurning people, why choose a projectile with such poor characteristics?

why choose a projectile with such poor characteristics?

... I live in canada and that energy is the legal limit before getting registered ...

And if i got my hand on a rifled 36" .177 barrel why not? But i doubt my parents would let me then, as it is not even biodegradable...

Why would you want a biodegradable barrel anyway?

The airsoft sniper rifle that I use shoots around 425 fps with .25 gram airsoft pellets. The gun has a 4x scope on it and although it's not exceptionally accurate, it is reliable enough to hit a soda can at over 25 yards 99% of the time.

Why would you want a biodegradable barrel anyway?

LoL not the barrel, the bb's ...

@ potatoflinger

Without the hop-up, is the bb going straight to earth the .25 is too much lightweight and it starts to curve with a .2g bb?

I really need to know if 500 fps is too much for a .25


Is 40 lbs on 10 inches too much to cock?

500 fps it not too much for a .25g . My piston rifle would shoot one at 660 fps, and they'd go pretty straight. I was able to shot a 20cm wide little tree from 60 meters away about 7 times out of 10 .
In a battle i got shot by a tanaka M700 that shot 500 fps with 0.36g , The sniper was 40 meters away, I swear to you had he been next to me the 10 seconds after, i would have lost my fairplay and punch him in the face. It hurts more than acceptable in a game. So, I insist on the fact you don't shoot anyone with it.

Demon wrote: @ potatoflinger

Without the hop-up, is the bb going straight to earth the .25 is too much lightweight and it starts to curve with a .2g bb?

I really need to know if 500 fps is too much for a .25


Is 40 lbs on 10 inches too much to cock?

I'm not exactly sure what you mean, but when I use bb's lighter than .25g they curve up a lot even with the hop-up turned all the way down. With the hop-up all the way down, I can reliably hit a soda can from across my back yard which is a little more than 60 feet. (with .25g bbs)

I very rarely play airsoft when it is really windy, but even the slightest breeze will throw light pellets way off course.

I would say that anything lighter than .25g is going to be pretty bad for accuracy. I only use .25g bbs because they are the heaviest that the local shop sells. I would like to move up to .3g or .4g bbs but i don't want to buy a bunch of them until I see how well they work first.

I'm not exactly sure what you mean,

I mean that to cock the airsoft rifle, i would need to push 40 lbs to re-compress the airchamber.

I meant your other comment, but for 40 lbs at 10 inches it would be pretty hard to compress, but it should be manageable.

Demon wrote:I have designed an airsoft "sniper" (by means i want to shoot further then 50m accurately)

And i wanted to know from you experts what could i expect from
.40g BB and 500 fps with a 530 mm tightbore 6.04 barrel(20") .

BTW, the trigger is very easy to pull.
I will keep an update on my work on spudfiles.

That really depends on the hopup. A few of my airsoft guns shoot 50m accurately no problem, they are shooting around 400fps(measured with .20's).. I normally use .25's in them however.

Hopup is the most determining factor for effective accuracy and range. (atleast in the velocity and weight ranges used in airsoft)

A 400fps gun with a crappy hopup will get out ranged by a 200fps with a good hopup.

There is a lot of common misconception about how a hopup in airsoft actually decreases the total range, this isn't true because it makes the BB fly straighter in the air and not just drop to the ground. It will also improve accuracy as it applies a good spin to the BB which helps for accuracy.

So I say, it really depends on the hopup chamber, the bucking (rubber sleeve that contacts the BB) and the nub(shaped peice of material used to press down on the bucking causing the backspin on the BB.)


My AKM with my hopup dialed in perfectly would fire around 170 feet effective.. (man sized target), with my hopup turned all the way off.. it had a hard time hitting a man sized target at 100 feet.. it really makes a huge difference..

Id say any "airsoft sniper rifle" project without a hopup is a joke.

According to GGDT, using .25 g BB's will produce 550 fps and .43 g BB's 450 fps .
All that at 3 ft/lb and one pump action at 37.5 lbs

What would be best to use for longer range?

@ DavidVaini

Can a good hop-up be homemade? It just appears that in my in-line valve design, there is the perfect place for a hop-up. It could be made out of neoprene with a screw on top and some aluminium /epoxy ... Maybe some sort of gears to get better adjustement.

.43's if its turely going to be firnig at 450... the extra weight will make a huge difference because of wind resistance.. lighter the BB the more it will "drop off" at the end of its flight..


Simply saying, a heavier BB will keep its speed more constant through the air for a longer time.

Its all about finding the right combination of BB weight, hopup adjustment, and power.

Its just like a race car... A race car with 1000 horse power and no traction to the ground will lose to a car with 500 horse power with good traction.

You really have to find the perfect weight, hopup, and power to get the best range.

Demon wrote: Can a good hop-up be homemade?

I have seen good hopups that are homemade, no reason they can't be made.. But mind you, I have seen some horrible hopups as well...

Perhaps looking at how airsoft hopups are made, you can effectively make a good homemade one.