Thread: Twist rate vs velocity vs bc

comeing into summer owning a 22-250AI running 75 GR A-max at 3450 i am at a similair experience to kiwi greg. as for twist rate there is two main concerns when useing a projectile lighter than intended for the twist

1. jacket core seperation / bullet blow-up, at extremely high RPM's this can happen with match and varmint projectiles but with premium bonded core projectiles or full copper variants are less likely to experience this scenario if at all.

2.velocity chokeing / skipping of rifleing, if this occurs it can effect accuracy and performance, although for this to occur you would need double the reccomended twist at near over-bore velocitys. as for velocity loss my experience is that there is no obvious change in velocity with twist rates exceeding the reccomended by 30-40%.

as for how excess rotational force effects the projectile at longer range's, in particular the transonic region is not something i have a depth of knowledge on myself. what i have observed is that under 300 yards most projectiles at high velocities have quite unstable rotation much like a rugby ball as it is first thrown it is quite unstable ( or in fancy speed pitch's and yaw's in an oscillatory manner https://www.youtube.com/watch?featur...&v=4pF8W5liSRc ), but at a certain part of its flight path it progresses into a stable rotation. a term used for a projectile as "going to sleep".

which is why i do not devote all of my development only to the 100m range as i have found that alot of loads that i have not deemed as being the most accurate ( although really close) have turned out to ruduce grouping size at 300m. anyway ill leave it at that before i go too offtrack if that hasnt happened already hope some of this is useful or atleast some what worth reading.