It really depends on how much jump you're talking about and whether the jump allows for feeding from a cartridge.Is there a negative for finding a load that shoots good by jumping the bullets?
Seating into the lands can eliminate variables for what goes on before the bullet is pushed into the lands and begins to be engraved. Along with there more consistent pressure build up and push on the bullet because of that. It tends to be more consistent than jumping. BUT . . . doing so presents the problem of having a bullet stuck in the land when the cartridge is battery and needs to be removed before firing.Is there a positive for finding a load that is into the lands?
No.Is there a negative for finding a load that shoots good by jumping the bullets?
The negative is leaving the bullet behind when you unchamber an unfired round.Is there a positive for finding a load that is into the lands?
Did you perhaps mean MORE jump means less case volume…?It really depends on how much jump you're talking about and whether the jump allows for feeding from a cartridge. Less jump means less case volume, which could result in too high pressure to achieve a particularly high velocity. A long jump could result in other inconsistencies with a load (e.g. concentricity for uniform engraving of the bullet as it enter the bore) to exaggerate an issue. Bullets with a secant ogive are particularly sensitive to jump making them difficult to get a good tune to a load.
Seating into the lands can eliminate variables for what goes on before the bullet is pushed into the lands and begins to be engraved. Along with there more consistent pressure build up and push on the bullet because of that. It tends to be more consistent than jumping. BUT . . . doing so presents the problem of having a bullet stuck in the land when the cartridge is battery and needs to be removed before firing.
YES!Did you perhaps mean MORE jump means less case volume…?
Absolutely. Thanks for the heads up. I hate when that happens.
Seating the bullet into the case reduces the volume.
LESS jump means there is more volume in the case as the bullet is further up the neck.
Or… That kernel into your trigger assembly and now you cannot either fire or reset the trigger… How do I know this…???!!! {:~/I agree with dthomas with one caveat, a round that gets stuck in the lands and pulls apart can ruin a match. It only takes one kernal of powder behind the lugs to make your gun lose accuracy.