i sighted in my ruger 300 win mag with federal premium 150 gr. TROPHY BONDED BEAR CLAW at 50 yards. is that good enough for shots from 40 to 150 yards

Go try out shots at 40 and 150 yards and see how high/low the bullet hits. It really shouldn't go more than a few inches low.

No, try it out to the 150 yards, pratice, pratice, pratice

Practice, practice, practice and then more practice! Know your rifle inside and out, and know it well. You should be 1 shot, and 1 kill period!!, but then that is just my own personal rule. When I cannot take a deer with 1 shot that is when I quit hunting.....

Sighting in a 300 Win mag at 50 yards is like putting rabbit ears on a new TV...I'd go with 2 1/2 high at 100...This should put you close to dead on at 150 and probably 3-4 inches low at 300....I always check my gun at 50, 100, 200, 250 and 300...Ballistic tables give you a rough idea...But I have found them not to be exact...Two different guns shooting the same loading will have different velocities...

Honestly this how i site my guns in i do dead on at 100 3 holes touching (if i can) then i shoot at 200 and 300 so i know how high i have to hold on those yardages dead on at 100 is usulally dead on at 25 and a little high at 50 about 2 1/2 inches so i would do that but whatever works for you

I would sight your gun in around an inch high at one hundred yards, that should get you about dead on at 150 with the ballistics of the 300win mag. Then after that make sure to check how it still hits at 50 and 150 and even 200 yards

This is from a balistic table that I found last year. I use the 150 grain Pointed Soft Point Core-Lokt. I sight in about 2.5 inches high at 100 yards.

Bullet Style Trajectory (inches)
100 150 200 250 300 400 500(yards)
Pointed Soft Point Core-Lokt 1.3 1.2 0 -2.4 -6.3 -18.9 -39.5
Pointed Soft Point Core-Lokt 2.7 3.1 2.2 0 -3.7 -15.9 -35.6
Nosler Partition 1.6 1.4 0 -2.8 -7.2 -21 -42.8
Nosler Balistic Tip 1.5 1.4 0 -2.6 -6.7 -19.3 -38.7
Pointed Soft Point, Boat Tail 1.7 1.5 0 -2.9 -7.2 -20.8 -42
Swift A-Frame PSP 1.8 1.6 0 -3.2 -8 -23.4 -47.8

So if if it is dead on at 50 it wont be on at 100?

Each gun and each load is different, and the only way to know for sure is to shoot at those ranges and find out. Sighting in at one distance, then shooting a game animal at another based on assumptions is a good way to make a less-than-lethal hit on a game animal.

I listened to somebody that told me where to sight in at 25 yards to shoot 250, and long story short, I educated a coyote (at 100 yards, mind you) because of it. In my rifle, that had me shooting 5.5" high at 100.[:@]