PJGunner, your comment about RL19 and 140g bullets is not something that had occurred to me before, but I think you are right on in your assessment that RL19 is too slow for optimal performance with 140g. bullets. I have never gotten desired velocities with RL19 and 140g bullets in any 7x57 Mauser or 7x57AI I've owned.
Note: I too have had difficulties obtaining MOA or better groups with Accubonds, in every caliber and every rifle I've fired them in. I've done so only with difficulty. Oddly, I've routinely shot far better groups with Partitions and Ballistic Tips, so that's what I use in Nosler bullets these days.
Regards,
Renaissance
