Board Thread:Off Topic/@comment-27144409-20190627122349/@comment-25396609-20190830020700

Too much logic is better than zero understanding of weapon design in general.

Kayla: The 'usual calibers' for rifles.... aren't EXACTLY a thing. 7.62 and 5.56 NATO are common in automatics, but marginally less so in bolt-action or semi-automatic models. I assume, since this is a clone of Wilt and Blush, you mean a bolt or pump action rifle; we're talking anything from a dinky little .22LR to the absolutely beastly 50 BMG and .308 Lapua Magnum

All that said your best bet is probably the 7.62. But keep in mind firearm caliber is a VERY diverse subject and doing some light research will be beneficial for future designs.

Study up a bit on melee weapons (modern and historical) too; as having an understanding of function and design will be actively beneficial to creation of RWBY weapons.