To add something to the above history lesson on 5.56mm ammo, back in the day, WW M193 55 gr ball had a distinctly different ogive than everyone else's. ( While re-organizing my loading area, I found a partial box of bulk bullets from that time, will have to see if I can find them.)

This design continued into the 1980s when WW got with the program and changed the ogive-or at least sold off all the previously produced bulk bullets.

Given the longer OAL, I doubt that they'd have delivered better results in extreme cold than a shorter bullet with the same rifling twist.

Remington did win the original cartridge design contest for the .22 infantry cartridge.