25 yard zero for a deer rifle.

[matrem]

I'm with d2wing on this one.

I tend to think of things in extremes to figure them out; If you rigged up a system to mount your scope a foot to the left of your barrel, you could certainly get the crosshairs & bullet hole to match at 25 or 50 yards (if you mounted it crooked or had enough scope adjustment), but what would happen on down range?
We know that bullet would hit further left as range increased.

That being said.Unless something is drastically wrong with the mount system, 50 yards is long enough to "prove" a .30/30 to the end of its deer killing range.

edit: to change wording in last sentence

 

[3212]

This was my method when I hunted with a 30-30 and had a short range to sight in.An adult deer has a vital area about 12 inches vertically. So if you're unsure of the distance to the deer aim high on the shoulder(not above the deer).The bullet can drop 10 inches and still hit the vitals.

 

[MartinS]

You'll be fine. 150 yards, get a little closer or aim a might high. A 25 yard zero trajectory is just another parabolic curve, it is not not sloppy or dirty.