The discussion centers on the effects of placing a gun against an immovable wall when fired, specifically regarding how this setup might influence the momentum and velocity of the bullet. Participants explore concepts related to recoil, momentum conservation, and the propagation of effects through different materials, as well as implications for bullet velocity in various scenarios.
Participants express various viewpoints on the effects of the wall on bullet velocity, with no consensus reached. Some agree on the principles of momentum conservation, while others challenge the assumptions regarding the wall's immovability and the implications for energy transfer.
Limitations include assumptions about the rigidity of the gun, the speed of sound in different materials, and the complexities of energy loss in the system. The discussion remains open-ended regarding the specific quantitative effects on bullet velocity.
This discussion may be of interest to those studying ballistics, firearms mechanics, or the physics of motion, as well as individuals curious about the practical implications of gun handling and recoil management.
Keep in mind that the total momentum has to include the gas leaving the barrel. The Lyman reloading book has the estimate in their equations and you can also find it with a web search. It is common for the gas to add 20% to the momentum.RobRobinette said:I used QuickLOAD, an internal ballistics calculator, to calculate some in-barrel bullet speeds. For a 357 Magnum pistol with a 4 inch barrel firing a 180 grain bullet, the bullet is going 200 ms at 2 inches down the barrel and 291 ms at the 4" muzzle. I googled the speed of sound through metal at 5960 ms.
It appears the shock wave through the metal frame will be almost instantaneous so I'm thinking the bullet's velocity will be affected, but by how much?