load data for .260R using hBN bullets

[AKDaddy]

I posted this in the reloading forum, but I think it might be more appropriate here.

I have a 260 Rem build in progress, and have also been experimenting with hBN coated bullets.

First, I hBN coated some 7mm bullets and shot them through my 7x57 Mauser with a known load. As expected, the hBN reduces pressure and hence velocity for a given powder charge, which means you can either increase the powder charge (if you have room) or use a slightly faster powder. This in turn means load data published for uncoated bullets isn't entirely accurate.

I plan to try 130 Berger VLD's, 123 and 139gr Scenars in my .260R. Are any of you shooting coated bullets (moly, ws2, or hBN) in this range and have some load data to share? For example, RL 15 is really too fast with uncoated bullets, but I'm wondering if RL15 might be perfect, especially with coated 123 Scenars. Any input would help!

 

[Heman]

I hBN coat all my bullets. That being said when I compared them to the non-hBN coated bullet I did not notice any velocity drop as one would expect. I do notice the barrel cleaning quicker though. So I think you're going to experience the same problems with hBN coated bullets at RE-15 as you do with non coated bullets and that powder. In my .260 I use N-150 with my 123gr SMKs and H4831SC with my 142s. Both prove to be very accurate for NRA XTC and LR matches.