None of them are. Militarily they are defined as "small arms"
Also, banning "high capacity" mags is essentially a partial ban on all semi auto firearms. ("high capacity" as defined by who and how?)
Since you have either a single shot or you have a semi auto, any size magazine is high capacity since it hold multiples of more rounds than a single. Even a wheel gun could be called high capacity since it holds 6 times as many rounds as a single shot. 600%! Thank of that!
An assault is defined as an intermediate powered selective fire small arm rifle. The M-16 and AK-47 being the most common examples. A battle rifle is a full powered semi-auto rifle. (Generally full 30 caliber, 308 or 30-06). The M1 and AR-10 are common examples. Modern sniper rifles are long barreled high power rifles generally chambered in 338 Lapua or Barrett 50 caliber, although in the right hands a 308 or 30-06 is still a very effective sniper round.