MaltaShootingSports.com Forum
SimpleMachinesForum     September 10, 2010, 16:43:59 PM
Welcome, Guest. Please login or register today with Malta Shooting Sports Forum!
« MaltaShootingSports.com ForumSpecific Interest ForumsAir Pistols and RiflesMuzzle energy and grains »
ThreadTools

Print


Random Pics



 (Read 375 times) 1 [2]

  Re: Muzzle energy and grains
« Reply #15 on: March 09, 2010, 15:13:18 PM » by Luger
Yes must agree. You will find the main ref to Joules in respect of German legislation whereby guns below a certain "Joulage"  Grin are "Frei" i.e. can be freely bought without licence or other formality.

Outside of that country and maybe a couple of neighbours, and in any case where else it really matters, it's feet and pounds and grains.

I would have no idea what you were on about if you said that a pellet weighed 1.3 grams!
RB


Nemesis,

Rightly so!

If at the Handaq Range you where to tell us that your gun does 240m/s with .55gram pellets doing 15.40J we would just stare at you thinking WTF!  Huh Is he trying to impress us or something  Grin Grin Grin Grin Grin
Logged

I'd rather be hated for who I am than loved for who I'm not!!!

  Re: Muzzle energy and grains
« Reply #16 on: March 09, 2010, 16:40:59 PM » by Vincent
Ok lets re-cap.
I tried to keep it simple so as NOT to look like we want to impress anyone.
The absolute kinetic energy formula is the simplest : E =1/2 x M x V x V
The answer will be in joules, because we are talking science not plebian and commercial convenience.

If you wish to convert Joules to Foot pounds: 1 Footpound = 1.356 Joules.

You can also convert your grians and feet per second to metric and  thereafter convert your Joules to foot pounds.

You can also use grains and feet per second direct using the  formula :   M v V x V / 450240
This will give you the Energy value in foot pounds right away.
If you look at this last formula you will still find the original 1/2 x M x V x V, but this time with the unit conversions built-in.


It sounds a bit complicated because we tried to "simplyfy" it.
The absolute is the simplest to understand and work with.
Logged

  Re: Muzzle energy and grains
« Reply #17 on: March 09, 2010, 22:03:10 PM » by nemesis
Luger, who is trying to impress?

I'm only still trying to learn here and impress no one.
Logged

  Re: Muzzle energy and grains
« Reply #18 on: March 10, 2010, 00:33:11 AM » by nemesis
Vincent thanks for helping me and sry if I'm bothering you.

But I think you didn't understand my last question.
You can't use the equation: M v V x V / 450240 for metric units (where M = Kg, V = m/s), can you?

Because I've tried to to work it out and the answers where completely different, even after conversion.

Is the constant number only applicable when using grains and ft/s?

OR

Should I use 1/2 x M x V x V when using metric units?

Thanks
Logged

  Re: Muzzle energy and grains
« Reply #19 on: March 10, 2010, 01:32:58 AM » by Luger
Luger, who is trying to impress?

I'm only still trying to learn here and impress no one.

Nemesis,

I was only pulling your leg mate.............you got no sense of humour? I always thought we put these  Grin Grin Grin  for a reason but I still tend to forget how sensitive people can be sometimes  Roll Eyes

Anyways if I thought you were trying to impress with all these freakin equations to find out the muzzle energy of an airgun pellet then I would not have posted back trying to show which units are best when calculating stuff in the airgun field, which pellet is better and for what..................

Well I'm definetaly out of this thread now, seems like people around here still take things personally no matter how you try to put things for them unfortunately.................

PS...........regarding your last question, as far as I know you cannot use the constant 450240 to calculate joules but only when calculating foot poundage.

Over and out.....................

« Last Edit: March 10, 2010, 07:26:58 AM by Luger »
Logged

I'd rather be hated for who I am than loved for who I'm not!!!

  Re: Muzzle energy and grains
« Reply #20 on: March 10, 2010, 08:42:48 AM » by nemesis
Luger, I'm sry but at that time I read the post I really didn't notice those similes. I took you a little bit seriously for a reason because in fact I'm not that sensitive.
The reason is that sometimes when I 'm asking about something just to learn it, some people tend to pull my leg all the time and end up with no info at all. Sometimes people thing that you're blufing or trying to learn the impossible. That's why I reacted to you post in that way, because I tought you where one of them. But anyway, I realized that you are not one of since you gave me some important info that I want to know.

Sorry mate & Thanks 
Logged

  Re: Muzzle energy and grains
« Reply #21 on: March 10, 2010, 15:35:07 PM » by Luger
Luger, I'm sry but at that time I read the post I really didn't notice those similes. I took you a little bit seriously for a reason because in fact I'm not that sensitive.
The reason is that sometimes when I 'm asking about something just to learn it, some people tend to pull my leg all the time and end up with no info at all. Sometimes people thing that you're blufing or trying to learn the impossible. That's why I reacted to you post in that way, because I tought you where one of them. But anyway, I realized that you are not one of since you gave me some important info that I want to know.

Sorry mate & Thanks 

No problem mate, everything's forgotten  Wink Grin Grin Grin

Thing is that I tend to instinctively joke around or pull legs and very often I'm grossly misunderstood and taken personally. It has happened before over here and it almost happened again  Grin

I can be serious when discussing airguns as you might have read in my earlier posts but some times the devil inside me just takes over  Shocked Grin Grin

Try and take it easy with the math regarding airgunning  Wink In my opinion the only formula you need to know is - pellet velocity (fps) x pellet velocity (fps) x weight of pellet (grains) / 450240 = foot poundage (ft/lbs)

If you are used to metric units, yes I agree with you it might be a little confusing and frustrating at first but once you get used to it you will forget about metric units. Trust me............been there, done that  Smiley

Once you start chronoing your gun for velocities in fps, you will get used to calculating ft/lbs so much that just knowing the fps of the gun will be enough for you to mentally calculate roughly it's ft/lbs without using the formula! Not joking here!

Just my 2 pence!  Grin Grin Grin
Logged

I'd rather be hated for who I am than loved for who I'm not!!!

  Re: Muzzle energy and grains
« Reply #22 on: March 10, 2010, 16:53:17 PM » by Luger
Nemesis,

Just remebered that I have an excel sheet which I use to convert anything you will ever need to convert in airgunning without having to use any math Wink

Find attached............hope you find it useful mate  Wink
Logged

I'd rather be hated for who I am than loved for who I'm not!!!

  Re: Muzzle energy and grains
« Reply #23 on: March 10, 2010, 17:51:06 PM » by bravoray
this is easier.................http://www.airguns.net/calculators.php
Logged

  Re: Muzzle energy and grains
« Reply #24 on: March 10, 2010, 20:00:56 PM » by leo
And this has all the conversions under the sun...

http://www.simetric.co.uk
Logged

  Re: Muzzle energy and grains
« Reply #25 on: March 11, 2010, 00:47:57 AM » by nemesis
Thanks to all of you with your help. I really appreciate it.
And Luger, thanks for that spreadsheet. Its really practical and easy to use. In other words it's excellent. I'm gonna use it alot hehe Wink
Besides for me, its still important to know how the formulas work for them(Which I finally understood), so thanks again for explaining to me how they work.

Thanks guys  Wink
Logged

 (Read 375 times) 1 [2]
Jump to:  
UserTools

Home
Help
Search
Calendar
Members List
Statistics
Login
Register



(Choose color)

LatestNews

Welcome to Malta Shooting Sports.com!

Register today with Malta Shooting Sports.com and join in the active discussions about your favourite sport and hobby!

Registration of new members.


ForumStats

17747 Posts
2309 Topics
422 Members
Latest Member: tinu7772

Powered by PHP
Powered by MySQL
Valid XHTML 1.0!
Valid CSS!



Powered by SMF 1.1.11 | SMF © 2005, Simple Machines LLC
Simplicity design by Bloc