If I had a 260 I would try loading 120gr Barnes XLCs with 46gr of IMR 4350 at 2949 fps, or 40.5gr of IMR 4064. I would also try Nosler 140gr partitions loaded with 44gr of IMR 4831 at 2820 fps.

I have loaded Nosler, Barnes and Hornady for my 223, 7x57 and 30-06 and all three were very accurate, under 1 inch with all three calibers and all three companies.