Sighting in trouble?
 

I went and shot my .308 today. At 50 yards I was hitting about an inch high and all fives shots were touching. I was happy and thought, if I'm an inch high then I may be dead bull at 100 yards. No, I was hitting 3 inches low at 100 yards and the fives shot were almost all touching.Why would I be hitting so low changing 50 to 100 yards? Should I sight in for 100? Would that make me 4 inches high at 50? I only had one box of shells and it was federal fusion 150 gr.. Should I test different ammo? Please, any advice would be welcome, thanks!!

RE: Sighting in trouble?
 

Sorry Chuck,

Something don't add. But yes sight in at 100 or farther. Honestly when you sight in at a given range, you can only guess where it will hit at another, educated guess but guess. Want to know where hit 300 shoot 300, 50 shoot 50.

RE: Sighting in trouble?
 

That sounded a little strange, so I pulled out the trusty old book.
On "paper" if you are an inch high at 50 yards,you should be about 2.5 inchs high at 100 yards. With a 100 yard zero, you should be about 1/4 of an inch high at 50.
Granted, this is "book" stuff, so there is a little wiggle room. But if you are high at 50, you should be higher at 100, not lower.

RE: Sighting in trouble?
 

The 30-06 is a similar round. If mine is dead at 150, it's an inch high at 100 and right on at 50 also. So if you sighted dead on at 50, you'd be 1 inch high at 100. something is really wrong with this. An inch high at fifty would be around 2-3 in high at 100.

What kind of scope you have?

RE: Sighting in trouble?
 

Check scope mounts and make sure they are the correct ones.

RE: Sighting in trouble?
 

Of course ring heightis a big factorhere,as is the particular load used.

RE: Sighting in trouble?
 

The only way this would be possible is if your ammo is only loaded to about 1400 fps.And this would be with thelow rings - only 1.5" above the center of the bore. Taller rings would only cause the point of impact to be higher at 100 yards with a 50 yard zero. Something just isn't right here.

RE: Sighting in trouble?
 

With a 5 shot group, "all touching" would be a 1.5 inch group maximum!
At 1 inch high at 50 yards, moving out to 100 yards, the POI shifted 5 to 6 inches, but held the group! Amazing!
It could happen, but the scope would likely have to be moved, and then retightened, or else the group would have started to open up.
A hot barrel could account for some of the shift, or the scope moved, but then stayed put throughout the second group.
If everything is tight on the scope you've got a big problem, and I would not trust the scope for hunting!

RE: Sighting in trouble?
 

I am not saying that the ring height or load explain this particular situation,rather I am pointing outthat they are factors that people neglect when they make assumptions where the point of impact shouldbe.

RE: Sighting in trouble?
 

Good point stubble. Wonder what height his scope is? It is truly amazing thoguh either way. We need to know more. :D