Originally Posted By: Shannow
Originally Posted By: hatt
The subsonic seems to be the only one that really benefits from this according to Federal ballistic data. The .22 mag isn't a long range target round. What other real world scenario is this going to come up?
http://federalpremium.com/products/rimfire.aspx http://federalpremium.com/products/rimfire.aspx
Wind drift is always related to the delay time (delta time of flight vacuum versus air), regrdless of velocity and time of flight.
Two bullets, same weight, same speed, different ballistic co-efficient, the one with the better ballistic co-efficient has less drift...not proportional to the time of flight, but due to the better performance of the good BC in air versus the other one.
http://www.dtic.mil/get-tr-doc/pdf?AD=ADA570469
Quote:
Abstract: This paper describes the internal, external, and terminal ballisticsof the 30-06 rifle cartridge.With cartridge case capacity of 68-70 grains of water and operating pressures up to 60,000 psi, the 30-06 launches 110-220 grain bullets with muzzle velocities between 3400 fps and 2400 fps, respectively. Low-drag bullets are available which make the 30-06 an effective and capable choice for target and anti-personnel use out to 1000 yards, but longer range applications are challenging due to the sonic transition. With an appropriate bullet choice, the 30-06 penetrates a variety of commonly encountered barriers. It also penetrates soft body armors and can deliver significant wounding effects even when stopped by hard body armor. At shorter ranges, wounding effects in human and deer-sized living targets are impressive and yield rapid incapacitation.
Quote:
Most ballistic calculators compute horizontal winddriftusing a procedure equivalent to the formula Wd = 17.6 x Vw x Tlag where Wd is the horizontal wind deflection (in inches), Vw is the cross wind velocity (in miles per hour), and Tlag is the lag time, or time delay between the time the bullet would reach that range in a vacuum and the time it actually takes when aerodynamic drag is included (in seconds).
It's counter-intuitive, but fact...you have to get the velocity and BC high enough to get the Tlag down to the same as a subsonic round to come back to the same drift.
It's just that in the world of trans-sonic bullets, the "delay" time is more for the supersoninc bullets out to a reasonable speed beyond sonic.
and a .22Mag doesn't get there.
I'm not arguing the physics. Lets talk real world. You don't like the .22 mag because of subsonic .22s. Those two aren't in the same category. The .22 mag isn't a target cartridge and subsonic .22 LRs aren't great hunting rounds at 75+ yards on coyote sized game. You've taken one case which is just about meaningless and passed ruling on every other aspect. Most people use high velocity .22 LR ammo. In which case the mag walks all over it in every ballistic measurement. If we're comparing apples to apples.
