chrispy88 wrote:can someone throw some light on the downsides to spinning a lighter bullet faster please?
A bit faster is no issue, if it's spun
excessively fast though the bullet can be "over-stabilized".
(Personally I think that's a s**ty term for it but that's the one that's coined and that stuck)
This is quoted from Shooting Times, the last point is key though...
Over-stabilization as a result of a too-fast twist rate can occur, resulting in a bullet that travels along its downward arc with its tip pointing skyward, exacerbating wind drift and hastening velocity loss. Ideally, the tip of a properly stabilized bullet should tip downward as the bullet begins its downward arc. Clearly, an over-stabilized bullet is not conducive to accuracy, but it is only noticeable in extreme cases of over-stabilization and at very long range. You’d never notice it at hunting distances.
It's not something your average shooting is going to encounter.