I heard about it via the MDWS forum, but there’s lots more info at a
https://texashuntingforum.com/forum/ubb ... /7506626/1
300 Ham’r sounds awesome, producing 1600-1800 lb-ft of energy with a decent 277WLV-like trajectory. However, it’s predecessor the 7.62x40 is basically just as good for most light projectiles, and, with a slightly shorter case length than the 300 Ham’r (”7.62x41”), it also fits the M80 ball, so I had MDWS make me an 18” 7.62x40.
If that’s important to you, then the x40 may be a better choice than the 300 Ham’r. If not, and because of SAAMI approval and full factory support, 300 Ham’r would be a better choice.
Hindsight:
2200 fps with the M80
plinkers out of an 18” x40 is not that much better than 1900 fps out of my 10.5” 300BLK.
If you have a satisfactory M80 ball load for the 300BLK, it’s not really as beneficial to have the ability to fit them in the x40 as I had initially thought.
I decided to normally run M80s in the 300BLK and designate all of my remaining 110 Varmageddon and 125 NBT for use in the x40. They will will last me a decade at the rate that I shoot the x40. Perhaps I’ll find some other .308 bullet to shine in the x40, but I haven’t yet.
Afterthought:
With a 100-200 lb-ft relative deficit, the 277WLV is overshadowed by both the x40 & Ham’r, but I have lots of bonded and solid copper bullets for the 277WLV, while my x40 bullets are all unbonded. If I need to hunt predators or hogs for extermination, I’ll reach for the x40 (Ham’r if I had it), but for harvesting game (deer) to eat, I’ll be better served by the 277WLV or even the 300BLK with Barnes black tips.
I hope this helps.