08-06-2022, 11:09 AM
Dt,
You cannot load longer than the mag in an AR and this is often the primary limiter. Stainless mags should give you a little longer than the calibre's standard of 57.4mm, so up to 58mm is reasonable but no longer.
If your distance to touch lands is shorter than the mag length then 0.5mm jump is a good starter. But be careful, especially with lighter bullet that there is enough shank being gripped by the case neck. It is more important to have no movement of the bullet as it gets violently pushed into battery. Enough grip depends on a how ductile your brass is, how much shank is in contact, how heavy the bullet is, and whether you crimp or not. I would square this away before thinking about how much jump. Frankly, jump-to-lands in an AR is almost a luxury given the mag length and all the usual influences of group size tend to be exaggerated in such a light-weight gun.
You cannot load longer than the mag in an AR and this is often the primary limiter. Stainless mags should give you a little longer than the calibre's standard of 57.4mm, so up to 58mm is reasonable but no longer.
If your distance to touch lands is shorter than the mag length then 0.5mm jump is a good starter. But be careful, especially with lighter bullet that there is enough shank being gripped by the case neck. It is more important to have no movement of the bullet as it gets violently pushed into battery. Enough grip depends on a how ductile your brass is, how much shank is in contact, how heavy the bullet is, and whether you crimp or not. I would square this away before thinking about how much jump. Frankly, jump-to-lands in an AR is almost a luxury given the mag length and all the usual influences of group size tend to be exaggerated in such a light-weight gun.