Page 2 of 2 FirstFirst 12
Results 11 to 12 of 12

Thread: Gas Tube Length, Dwell Time, Gas Port Size- Do They Really Increase/Decrease Recoil?

  1. #11
    Join Date
    Oct 2010
    Posts
    962
    Feedback Score
    21 (100%)
    Agreed.

    Quote Originally Posted by bkb0000 View Post
    if there was nothing in the bore, as in a complete vacuum, the propellant blast from a blank would still move the weapon rearward by itself. not by much, unless it was also in a state of inertia, but its still part of the equation.

  2. #12
    Join Date
    Oct 2010
    Posts
    962
    Feedback Score
    21 (100%)
    First of all please excuse the crude drawings, they are not to scale and do not represent the actual part geometry. I'm a visual person myself so I thought this would help.

    The first picture represents the rifle and the bullet as two solid, independent bodies. Because the bolt is locked until the bullet passes the gas port, they can be analyzed this way. The blue arrow represents the force of combustion acting on the bullet and the rifle body. This action is equal and opposite. We know that the mass of the rifle body is much more than the mass of the bullet. We also know that the force acting on both bodies is equal. If we consider the equation F=ma (force = mass x acceleration) we can conclude the the acceleration of the bullet will be much greater than the acceleration of the rifle body. Furthermore, we can use the muzzle velocity and bullet weight to figure out the energy given to the rifle body (I keep saying body because I want to emphasize that at this point that the entire rifle can be treated as a solid piece).

    I'm sure you're all familiar with the second picture, there are much better pictures and animations available. I just wanted a visual aid. After the bullet passes the gas port, the gas is sent to BCG, unlocking the bolt. The rifle can now no longer be treated as a solid piece.


Page 2 of 2 FirstFirst 12

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •