Thread: Reloading 6.5x55

Greetings,
Found my notes. My aim with working with the 6.5x55 was to make some sense of the highly variable data and develop a decent load rather than a hot one. The base data used was that for the .260 Rem. John Barsness wrote some excellent articles on loads and pressure as well as the relationship between case capacity, velocity and pressure. The one I used was that possible velocity increases at 1/4 of the increase of case capacity. Usable case capacity in the 6.5x55 is around 6% greater than the .260 Rem so an increase in velocity of around 1.5% should be expected. based on that the possible velocities for the 6.5x55 should be:
120 grain 3,000 fps.
129 grain 2,890 fps
140 grain 2,730 fps
These are for the soft cup and core type projectiles with possible velocity being a bit less for the harder projectiles.
My load for the 129 grain SST was worked up to 2,870 fps using later lot AR2209.
It appears that velocity and pressure are more closely linked than either of them and powder charge. The data for most 6.5mm cartridges is quite varied even using the same projectile. The Hodgdons data is a close match to my rifle even if lower in pressure than I wanted. It was also for the older AR2209 rather than the current faster lots. Data for the 6.5-06 is way of for the rifle I have been working with with chronographed velocities being substantially lower than predicted. Working up to velocities makes more sense to me.
Regards Grandpamac.