The new 7.62 X 40 cartridge brings some excitement to the AR 15 platform; .30-30 ballistics from an AR. One problem was the lack of a light-weight, high weight retention bullet that would expand at the lower velocities. Barnes has solved with with their new Tipped Triple Shock designed specifically for the 7.62 X 40 WT cartridge.
These bullets have been optiminzed for a muzzle velocity of between 2300 and 2600 fps. So, not only should they work great with the 7.62 X 40, they should also be an option for low recoil / slower velocity loads in medium sized .30 caliber cartridges like the .30-30 Win. (In non-lever guns.), .300 Savage and even the .308 Winchester.
Bill Wilson has been testing these bullets and seems pleased with the results.