At one time I had a Remington 40X Custom Shop Sporter that was very accurate and mounted on top was one of the Shepherd 3.5-10x40 range finding scopes calibrated all the way out to 500 yards.
At the time the longest range available to me was 300 yards but hitting a silhouette target 5/5 in the body was not very difficult if the wind wasn't blowing too hard. On a dead calm day you could do heard shots, maybe 3/5, most of the time.
I posted this over on the old Shooters.com and was called a bald face liar by one of the members over there. Turned out after I told him who I was and where I shot he was an acquaintance who was on the Board of Directors where I was a member. After he came down and shot the gun, hitting the silhouette in the head at 300 yards, he issued a public apology.
If you have never seen or used a Shepherd they are great scopes once you understand them. I have them also on a .223 and .308 Remington LTRs and have shot some very small groups out to 800 yards with these guns.
Bob