Login    Register
User Information
Username:
Password:
We are a free and open
community, all are welcome.
Click here to Register
Sponsored
Who is online

In total there are 71 users online :: 3 registered, 0 hidden and 68 guests


Most users ever online was 155 on Mon Aug 15, 2016 1:40 am

Registered users: Bing [Bot], Google [Bot], Yahoo [Bot] based on users active over the past 5 minutes

The Team
Administrators
Global Moderators
global_moderators.png CS

Most accurate/predictable 6~15mm airgun ammo?

Post about things you have launched or thought about launching. Also post about various materials used for building cannons. No posts about explosive projectiles!
Sponsored 
  • Author
    Message

Unread postAuthor: Labtecpower » Sat Jul 14, 2012 2:34 pm

mm.. beetje ver weg :D
  • 0

"ñøw mÿ šįg šüçkś!"
User avatar
Labtecpower
Major General
Major General
 
Posts: 1267
Joined: Sat Feb 20, 2010 6:38 am
Location: Herb Island
Reputation: 7

Unread postAuthor: jackssmirkingrevenge » Sat Jul 14, 2012 6:36 pm

Tsukiten wrote:What matters to me is that the projectile doesn't come to a dead stop (zero horizontal velocity) before reaching 50 meters. If the projectile would impact the target at an 45-degree angle, that really is good enough for me. As long as there's a chance that the numbers produced by equations and there real-world results match up a bit.


This doesn't really make sense.

Let's say you have a series of targets - let's say beer cans :D - at 5, 15, 25, 35, 45 and 50 metres.

You can hit all them with a $3 airsoft pistol, or an M16 assault rifle.

This is a ballistic chart for the round fired by the M16:

Image

At 50 metres it's shooting practically in a straight line, with almost no bullet drop and no time for environmental factors like wind to significantly affect the bullet. At all the distances mentioned above you can aim at exactly the same spot without caring about wind or gravity, and always hit the beer can.

Have a look at some data for airsoft BBs (fromthis epic study! This section in particular.)

Image

To hit the target at 50 metres with the BB gun, you'll be shooting up in the air like you're holding a starting pistol and will need one of these to sight:

Image

You'll also need one of these to know precisely what wind direction and speed was, air temperature, pressure humidity...

Image

You also need a laser rangefinder to know the EXACT distance to the target:

Image

In a nutshell, if you want to avoid all these ancillary items, you want to be firing as fast as possible in order to have as flat a trajectory as possible.

About power: currently I'm trying to measure the spring rate of the spring I have, after which I can calculate what its maximum performance would roughly be like. If that doesn't look very optimistic, I can go pneumatic or try out that crazy idea of mine with rubber bands.


I made this when I was young. First and last springer I ever made.

A pneumatic is a much, much, much better idea ;)

Note that the rubber bands will not directly drive the piston. The rubber bands could for example drive something along 5 times the length of the piston, after which a system of pulleys or gears or whatever transforms the length of displacement into the length of the piston and thus multiplying the excerted force on the piston by 5.


Won't help you I'm afraid, don't forget that pulleys or gears involve energy losses.

But secretly, I'm hoping to prove everyone wrong


You're welcome to try, and I don't mean to sound discouraging, but I'm 100% sure you'll be wasting your time ;)
  • 0

User avatar
jackssmirkingrevenge
Donating Member
Donating Member
 
Posts: 24225
Joined: Thu Mar 15, 2007 11:28 pm
Country: Holy See (Vatican City State) (va)
Reputation: 66

Previous

Return to Construction Materials/Ammo Discussion

Who is online

Registered users: Bing [Bot], Google [Bot], Yahoo [Bot]

Reputation System ©'