[MrChem]

S&W's new 5.45 x39 AR

I just read an article in Guns N Ammo comparing this rifle and bullet to the AR-15 and the 5.56 x 45. It is an interesting read and they seem to favor the Russian round due to its superior stopping power over the 5.56 lead core Nato round. They attributed the increased stopping power but loss of accuracy on its steel core construction and longer bullet. For the same weight, the 5.45 Russian bullet (not case) is longer than a similar weight 5.56 round. Personally, to me it is just another varmint caliber. I am old school and still think a battle rifle should be 7.62 (30 cal). If it is not a good enough to hunt deer then it is not good enough for combat in most cases. Just my :2cents:

 

[magikbullet]

Re: S&W's new 5.45 x39 AR

stopping power... :

the 5.56 is superior in pretty much every regard. but 5.45 is cheap, and shooters want to be able to shoot without selling a kidney for ammo...

 

[dont_tread_on_me]

Re: S&W's new 5.45 x39 AR

The 5,45x39 was designed around a longer projectile to be less stable post impact.It also had a cavity in the tip to produce more and faster yaw,to get the bullet rotating sooner to create more tissue damage and a larger temporary wound cavity.The 62 grain projectile used in current 5.56 ammo is very stable when fired from a 1:7 twist barrel,unlike the older 55 grain load which destabilized faster upon impact because it wasn't as stable in flight.
Another problem compounding the 62 grain loads stopping power is it being fired from the shorter M4 barrel.All these loads are heavily dependant on velocity to generate stopping power,not to say they are not lethal,but do not generate as much hydrostatic shock,which shuts down organs etc,the thing I believe that determines stopping power the most.
I don't believe a 30 caliber projectile is necessary to get a good combination of stopping power and combat load weight,and recoil.I believe a projectile in the 95-110 grain range,somewhere between 6mm(.243),.257,or 6.5(264) traveling at or above 2500 fps would be ideal.keep in mind projectile shape,and bullet construction/design plays a major role in performance.Last,but what should be first is emphasis on shot placement.The greatest cartridge in the world,whatever the hell that is,will have no effect if it misses,or as the old saying goes "a hit with a .22 is better than a miss with a .45".