The logic of 300BLK is simple: twice the weight of metal at the cost of slightly less flat trajectory. At 100 yards, the difference in drop is only 2″, at 200 it grows to 8″. Still within point blank for a human opponent. The benefit is greater penetration and larger wound channel. Since most defensive rifles are used up close, seems like a good trade to me.
Why not stick to 7.62×39?
300 blk can be used in a standard AR – same mags, same lower, same upper(!) – the *ONLY* thing that changes is the bbl.
From a .mil logistics perspective, this is spectacular – no need to scrap hundreds of billions in inventory!
It even uses the same BRASS as 5.56/223 – it’s just necked to a different bullet size!
X39 OTOH would require new mags at a minimum, and IIRc new b/c’s, in addition to the bbl. New brass-factories would have to be set up… `
Part of the design intent of the .300 blk is to use the existing AR platform. The 7.62×39 can’t because the round requires a greater magazine curvature than the AR magazine well can handle. Otherwise, the weapon will feed like an anorexic bulemic with prom one week away, i.e., “not well, not very well at all.”
As noted above, same lower, same upper, same mags, same BCG and bolt. Change the barrel and voila!
This cartridge make most sense in a suppressed rifle. Terminal ballistics, the bullet needs to tumble to be effective since it does not go fast enough to expand.
You have to be careful with it. Some guy once inadvertently stuck his mag with .300 Whisper into his other AR chambered in .223. The Sierra 240gr Matchking makes a VERY long bullet when swaged down to .22 caliber (there was a picture, Precision Shooting magazine). Kinda hard on the gun, too.
i hunt to kinds of deer mule deer in the hi desert and black tail deer in the moniuatns .i like a long flat shooting gun for mule deer like a 7mm remington mag,270win.338win mag . all can be hard on the deer . all big guns most with hi recoil for a new or small shooter. in the mt i like a small lite brush gun like a 243win, 308win -7.62 nato , 300 savage i have even let my wife shoot a 223 remington to small some say but the last deer she shot dropped like it was hit my a mack truck i aways say start small the 243 win is the most popular with most deer hunters cheap to shot and you can buy ammo anywhere