I see that there are AR15 mags specifically designed for the 300 ACC with claims that 5.56 design mags do not preform well with 300 AAC. .
Does any one here have any information about the 300 ACC not feeding reliably from mags designed for the 5.56 nato cartridge?
Does any one here have any information about the 300 ACC not feeding reliably from mags designed for the 5.56 nato cartridge?