Good grief! Good manners cost nothing. Apologies to anyone who is bored by this discussion and irritated by the rudeness latterly displayed, but misinformation should be corrected..
khj wrote:
No, of course I am not wrong. Untill the gun is fired, there is no recoil! I think even you will admit that....And recoil force stops when the bullet has left the muzzle, and gas pressure equals ambient pressure.
Well, I'm sorry to have to correct you again. The thread is about perceived recoil and has discussed the recoil primarily of blowback pistols, rather than other, locked-breech actions. In a blow-back action, the major contribution to the perceived recoil is the slide reversing its direction of travel as it slams back against the frame.
This happens some time after the bullet has left the barrel.
The forces on the frame of a blow-back pistol are complex: the first applied force will be due to case-to-chamber friction. Previously in this thread, I have assumed this to be insignificant in .22 pistols, but I'm happy to see evidence to the contrary. This force acts directly on the barrel, thus directly on the frame. As the bullet is forced along the barrel, barrel friction causes a force on the frame in the opposite direction. As the bullet exits, the muzzle blast acts on the barrel. As the slide begins to recoil, it cocks the hammer against the hammer spring and compresses the recoil spring. These forces are reacted by the frame. As I've said, earlier in the thread, the cocking force varies dramatically with slide position, and some designs allow a 'smoother' cocking action than others. Therefore, the forces transmitted to the frame by trigger cocking will be quite different from one design to another. Slow-motion videos have been referenced, showing that, in spite of these forces acting on the frame whilst the slide is recoiling, the gun hardly moves in the hand, even after the bullet has left the barrel. It is when the slide hits the stop that the gun kicks in the hand.
My definition of the
impulse of a force is text-book correct, as any student of elementary mechanics should know. Perhaps you are not familiar with this terminology: from your use of English, I suspect that English is not your native language. We may be arguing solely about semantics.
My admittedly loose use of 'derivative' and 'integral' was my musing that it is not clear from the literature just how importent, from a subjective point of view, are the various parameters of the recoil phenomenon. In other words, (and this is more musing, not tight, well-worded physics!) when we feel recoil, are we mainly conscious of the velocity of the gun, its momentum, the force applied to the hand, the rate of change of force or velocity (or anything else), the distance the gun moves in the hand, the energy dissipated in the hand, work done in compressing the tissues of the hand, etc., etc.? As I've said, I'm humble enough to say I don't know, but I do understand basic mechanics!
khj, rather than trying to make honest contributors seem fools, which is tedious and out of place in this forum, perhaps you could address the subject of the thread and enlighten us all. Most of us remain humble enough to listen with courtesy and eager to learn.