1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Calculating Rifle Performance

  1. Jul 5, 2011 #1
    Say fired from this gun; it's a gun i made from Pimp My Gun, but it's not real. however i'm curious of what is it's performance; Muzzle Speed, Muzzle Velocity, Recoil, and Effective Range at 50" of barrel. using normal and +P+ ammunition

    Infinite Conundrum
    .338 lapua Magnum
    x98 Telescopic Sight
    7 round magazine
    15 kg (loaded)
    Bolt Action.

    Infinite Conundrum is a bolt action sniper rifle with the action just two movements; forward and back. the barrel itself is 50" inch, the powder load of the round is +P+, the weight of the bullet is .300 grains and a bullet which is DU; Depleted Uranium.

    what would be the maximum range?
    the Muzzle Velocity
    The Muzzle Energy
    the Recoil.
    of the two differing ammunition?

    Last edited: Jul 5, 2011
  2. jcsd
  3. Jul 7, 2011 #2
    and what if it has another variant; it can shoot .338 Lapua Super magnum (DOES NOT EXIST), though it's a theoretical round, it is a .50 BMG necked down to accept .338 lapua magnum bullets, ackley improved and the case length is still 99mm.

    what would be the new velocity, muzzle energy, recoil and range?
  4. Jul 7, 2011 #3


    User Avatar
    Staff Emeritus
    Science Advisor

    First, this isn't a forum for random questions about fake things. (Your 2nd thread on something like this) It would be greatly appreciated if you stuck to real examples for now. I only say this because of my next points.

    Second, you haven't given us nearly enough info to answer these questions. We don't know how much powder is in the cartridge, the shape of the bullet, etc.

    Now, we CAN help you figure this out on your own, if you would like. Do you know how to calculate the acceleration of an object using its mass and a force?
  5. Jul 7, 2011 #4
    sorry, it's just answers are hard to come by at other stuffs, and they even TROLL. some guy answered at my question on my YahooAnswers something about being less faster than superman... what kind of answer is that?

    anyways if you want more info... here;

    .338 lapua magnum
    114 gr
    spitzer type bullet
    200 grain Full Metal jacket bullet

    the gun is 50 inch long.

    .338 Lapua Super Magnum
    300 gr
    spitzer type bullet
    barrel length of the gun is 50 inch.
  6. Jul 7, 2011 #5


    User Avatar
    Staff Emeritus
    Science Advisor

    Alright. So, the .338 Lupua Magnum generates 3,340 Feet per second muzzle velocity using a 200 grain bullet. (Per the Ballistic Performance on: http://en.wikipedia.org/wiki/.338_Lapua_Magnum)

    That equates to 6,734 Joules of energy. (Also right there next to the muzzle velocity)

    For the 300 grain its about 2,750 ft/s and 6,810 J. (Same place as before)

    Both of those velocities were using a 26 in barrel, and I don't know how to figure out what a 50 in barrel would produce.

    Considering that this cartridge was used at a range of 2,475 m to kill someone, albeit with a low drag bullet, that should be a good estimate on its max range at the above specs. (assuming that the extra barrel length provided a decent boost to velocity of the bullet)

    I can't give you anything beyond that, sorry.
  7. Jul 7, 2011 #6
    oh... thanks anyways... but seriously thanks...

    oh and sorry if my questions is theoretical, and i mean at first look; way off reality..
  8. Jul 7, 2011 #7


    User Avatar
    Staff Emeritus
    Science Advisor

    It's not they are theoretical, it's that it's easier to use a real life example of something that does exist first and go from there. This applies to the forum as a general principle. A good example is your post about a supernova. There's no problem asking questions about it, but it REALLY throws people off when you start asking "what if" questions when you don't understand the basics. This specific post isn't really too bad, it's just that I came directly from your other post over to this one. I'm sorry I couldn't help you further.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook