Rifle scope zero-elevation changes

[260AckImp]

Hopefully this isn't a dumb question
Ive just got a question regarding scope zeroing. On the weekend my friend and I reloaded some ammo for his rifle. He has had said rifle for 6 months or so and had it sighted in etc. With this new ammo he decided to sight it in at 110 yards but the elevation change from him to the target was at least a good 27-30 yards downhill. He has shot 10 rounds, they all shot 1.5-2 inches high and he has moved the scope down for a zero. We went hunting the next day and even on mid sized game like pigs at 75 yards he was shooting very high. Would this be due to him zeroing in his scope while shooting at a target that's downhill instead of shooting at a target that's directly inline with his rifle??
Thanks for your time, information greatly appreciated

 

[Texas10]

Just trying to understand, so you're saying the target he zero'd his rifle on, with your reloads was 80 to 90 feet (27 -30 yds) below horizontal at 110 yds?

I would think his rounds would be landing very low with that zero, not high. Maybe I'm just not understanding it.

 

[Kermit in Va.]

Might have went the wrong way when he adj...

 

[theMadAlaskan]

Shooting at a steep uphill or downhill angle flattens the apparent trajectory. If your sighted in normal and shooting up or down you have to aim as if it's closer. Trying to wrap my head around which way it would go if you sighted in on an angle....

 

[260AckImp]

Yes that is correct, he was shooting at a target that was 27-30 yards below him. I thought the same in that he would he of been shooting low not high. He had to re zero while hunting and he had to wind his scope 5 MILS down to get it back to zero at 100 yards. Was very strange

 

[Ned Ludd]

Shooting uphill/downhill requires less elevation than shooting perfectly level. He would therefore have dialed his elevation down by some amount in order to sight in as you described. As a result, any subsequent shots he took that were close to level with that zero would end up low, not high.

 

[260AckImp]

Ok thanks for everyones input, I thought it should of been shooting low and not high. Very weird that it was shooting high

 

[ppaul]

the bullet crosses your line of sight twice on the way to the target, is it possible.....

 

[Shawnba67]

If you sighted in on a perfect horzontal plane. how much POI shift would you expect shooting at game slightly downhill at 75 yds?
Correct Nearly None!
Your overthinking this.
There was a user error sighting in.

 

[hogpatrol]

Lifting his head.

 

[ToddKS]

I just dialed a 45 degree downslope into my Strelok app. According to that data I would have to dial down .7MOA at 100 yards.

If zeroed on a downslope the shooter should be low to a true horizontal zero. Also, the change is not that significant at 100 yards. If you use 200 yards and a 25 degree slope the difference is 1.3MOA @ 200 yards which would not be sufficient to cause a miss on medium size game if the shot is properly centered in my opinion.