News on 7x46mm Murray cartridge.

[ra2bach]

This article is the most accurate public account I have encountered discussing the 6.8 mm genesis and appears to answer many of the questions posed regarding early 6.8 mm development: http://demigodllc.com/articles/6.8-m...-arms-carbine/

For cartridges intended for combat use, you will likely want to avoid sharp shoulder angles...

7.62x51mm definitely remains a viable combat cartridge, especially when fed effective ammunition--the problem remains which modern rifle is reliable, durable, and ergonomic enough to be a viable option on the current battlefield...Mk17 shooting Mk319 seems to have potential, but time will tell.

thanks Doc, this is outstanding information.

to the OP, sorry for the hijack of your original subject the 7x46 Murray cartridge...

[BAC]

While an interesting (long!) read, it unfortunately doesn't answer my question about the specifics behind why the SPC case size and shape were chosen. I understand that it's somewhere between a 5.56x45 and 7.62x39 in dimensions; that part makes sense to me. I guess what I'm most curious about is whether body length, shoulder angel, neck length, and overall length were really played with at all during the SPC's development. Shoulder angle is something I hear a lot about but that doesn't seem to be problematic in bolt guns or the AR family of rifles (6mm PPC, 6mm AR, 6.5 Grendel, the various Ackley Improved rounds, etc.). I understand that competition shooting isn't combat, but it's something that at least warrants testing, no?


-B

[ra2bach]

While an interesting (long!) read, it unfortunately doesn't answer my question about the specifics behind why the SPC case size and shape were chosen. I understand that it's somewhere between a 5.56x45 and 7.62x39 in dimensions; that part makes sense to me. I guess what I'm most curious about is whether body length, shoulder angel, neck length, and overall length were really played with at all during the SPC's development. Shoulder angle is something I hear a lot about but that doesn't seem to be problematic in bolt guns or the AR family of rifles (6mm PPC, 6mm AR, 6.5 Grendel, the various Ackley Improved rounds, etc.). I understand that competition shooting isn't combat, but it's something that at least warrants testing, no?


-B

the way I read the article, the case was chosen because of head size and desire to provide a larger bullet that would fit in the AR platform. any larger head size and it would have required removing more metal from the AR bolt, or using a rebated rim, which they tried but rejected.

OAL length would be decided by magazine length, neck length by caliber and shoulder angle by tried and true. if you look at modern cartridge design, a 30% shoulder is at the beginning of steep with the Ackley Improved 40% angle about at the limit for reliable feeding in a bolt actions. if you look at the military cartridges, the shoulder angle hovers around the 20-26%.

[rezin23]

Any news on this round?

[Microalign]

Interesting caliber. I've always wanting something that was right in between the .308 and 5.56, and this seems to hit the mark.