I have both the Z8i rail mount scopes in 1.7-13x42 & 2.3-18x56. I use the 1.7-13 on my 8x57 and the 2,3-18 on a .300Wby. Both are wonderful scopes. I like them a lot, I think the 1.7-13 is my favorite though and it would work well on either caliber. I don't know if you have considered the Z8i 1-8x24, I have one on my .375H&H and find it to be muy bueno. I think rail mount scopes are perfect for Blaser rifles.