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.30g
348 fps
5' 9"
Is this formula a projectile motion physics equation? At least for the flat hop?
 

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Discussion Starter · #122 ·
.30g
348 fps
5' 9"
Is this formula a projectile motion physics equation? At least for the flat hop?
Your numbers are up.

This is a bunch of equations that tell me a lot of information :) mainly it tells me the max distance your BB can travel at a certain FPS and RPM. This then allows me to adjust the angle of engagement and the RPM to find the "sweet spot" where the flattest trajectory can occur and the max distance with those numbers.
 

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How about mine?

.40g
377 fps
5'11"

.40g
350 fps
same height

.32g
350 fps
same height

.32g
300 fps
same height

.32g
280 fps
same height

.30g
290 fps
same height

Sorry for so many, I am very interested in this.

Also, I'm curious: What language did you program the application in?
Thanks!
 

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Cool! Thanks Geograd. And happy new year.
 

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Discussion Starter · #126 ·
alright heres a different way of looking at it

.30g bbs
I am 5'7"
What would be my best FPS setting for my maximum range?

thanks!
My equations aren't set up to calculate that but putting in some FPS I've figured out that around 350 FPS and a 3 degree angle with .30 seems to be a good trajectory and distance.

It's pretty straight with a slight up and down reaching out to ~255 feet flat.
 

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Discussion Starter · #127 ·
Zardichar you mass amounts of data are up :p lol Also I programmed it in Java. Once you know what equations you need it's really easy to create because the equations do all of the work :)
 

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Hi Geograd

I changed to 0.4gm bb's to see if I could get better accuracy and range. (You suggested 0.43gm but I could not find any in a light colour although I do have some 0.43 black bb's). Originally I was using 0.3gm with a 550mm barrel. When I used heavier bb's I found that my accuracy was going out the door. It was terrible. Anyway after some evaluating I thought that I should use a shorter barrel as I had tuned my gun to use all the cylinder volume on a 0.3gm bb. So there was not enough volume to accurately push out the heavier bb's.
Anyway, I tried out 6 different length barrels and found that 470mm was about the best for the 0.4gm bb's. (Note: I did not get to try a 500mm long barrel but I have one on the way) Accuracy was great and I am getting about 100m's range when previous the max range was about 80m's.
Another interesting point was that when I used a 0.4gm bb and a 310mm long barrel joule creep started to work quiet well. I was getting a variance of 0.4 joules between the 0.4gm bb and the 0.2gm bb. The only downside was that since the barrel was so short it meant that to get high FPS, I needed to put in a very big spring.

So thanks Geograd for getting me to use heavier bb's in the sniper.

I am still to experiment with heavy weights and low FPS (350fps). I have done a little experimenting but have had no success with it but I will tune the cylinder to the weight of the bb and then let you know.
 

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Discussion Starter · #130 ·
Yep, you nailed it on the head 1tonne. You need enough volume of air to push out the weight of BB per the length of your barrel. It's always better to slightly over-volume on a spring sniper, there is no drawback.
 

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This doesn't take into account hop or firing stance, most sniper lay down when taking the shot so the time taken for the bb to fall would be less and the range shorter.

Let's say the time taken for a .20g bb to fall 2 metres was 0.5 seconds, and the gun was firing 328 fps then

0.5 x 328 = 164ft

So your range could be halfed if crouched.

If you wanted to know range accurately you would need to know exactly how long the bb takes to fall with perfect hop which differs with every rifle.

Sent from my iPad using Tapatalk HD
 

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This doesn't take into account hop or firing stance, most sniper lay down when taking the shot so the time taken for the bb to fall would be less and the range shorter.

Let's say the time taken for a .20g bb to fall 2 metres was 0.5 seconds, and the gun was firing 328 fps then

0.5 x 328 = 164ft

So your range could be halfed if crouched.

If you wanted to know range accurately you would need to know exactly how long the bb takes to fall with perfect hop which differs with every rifle.

Sent from my iPad using Tapatalk HD
From What I can tell it does take into account your firing stance. Geograd has asked for the height of the person firing the gun. So standing up. If you wanted to get some lying down statistics then tell him your height while lying.
Yes, Hopup can vary but this type of guide is an estimate. This guide though does seem accurate with high FPS guns but I am a little unsure about the lower FPS gun statistics.
 

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I admit the method works well but knowing the time taken to fall is extremely hard to find out and can differ greatly in each rifle but your completely right about changing for height, I was a bit hasty dismissing this as useless
 

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Discussion Starter · #134 ·
With hopup your BB falls very quickly when the hopup finally fails to create lift (aka the spin slows down too much). That's the purpose of hopup, to defy gravity :)
 

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Discussion Starter · #136 ·
5' 7"
.30g bb
@ 350, 400, 450, 500 FPS

And to test 1Tonne's idea of prone, could you try a height of 10 inches?

Thanks Geograd! (You might be able to tell I've got a regulator on my KJW :D)
At least you kept it with a single weight. I have to recompile for different weights lol. I'll get your numbers in a moment. Also, I don't know about anyone else but I tend to find most airsoft snipers don't actually fire from prone, most fire from crouch because of the difficulty of seeing from prone through goggles/mask. I could be wrong though.
 
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