re-center or zero the scopes crosshairs

[THG]

I am going to be putting an old scope on a different gun was wondering if there is a way to re-center or zero the scopes crosshairs so when sighting in I would have the maximum horizontal and vertical adjustment on the scope. Is this even necessary?

[MTCOMMER]

I hope I understand your questions....
Well, my scope has a 0 on the dials, so if you set both to 0 they will be back in the center.  Atleast thats what mine does.... If you are putting the scope on a similar gun (with similar bullet velocity, etc) - so a 30-06 to another 30-06 you SHOULD be able to get away with just a minor sighting, unless your mounts are off!
I would not worry about changing the adjustment until you get out on the range, or put them to 0 like I stated before and start from scratch

[Benny]

I think one can trun the scope adjustment all the way down/up, then count how many clicks it is to the the stop in the other direction.
Then go back half the number of clicks, this will be the center of your adjustment range.

But I think your better off just mounting the scope, then do a bore site if you have the equipment to do so or start at  25 yards and shoot a round to see where it hits.

If your way off and can't see the hit you may need to have some one watch over your shoulder had see where your hitting and adjust from there.

Benny

[THG]

Took Redfield 2 3/4x off my wife’s Ruger 44 auto deer rifle and put it on new to me vintage Marlin 22 auto 989 M2. Yes I have a better scope I can put on her rifle. Got some nice smooth curved 1” rings with 3/8” base for $9.99.
First 3 shots were 4” low and 2 “ left, after adjusting scope the next 3 shots were 1” right of the bull’s eye. A second adjustment and even I can keep 7 shots in the 1” bull at 25 yards. Boy, I had forgotten how accurate the vintage Marlin’s micro grove barrel is. 
Any way no need to re-center crosshairs and everything turned out ok. Thanks everyone for your help.

THG

[cva54]

the way I see it count the clicks if it aint got a O market on it. If it is a bolt action rifle its going on just pop out the bolt and eye ball it get the bore & the scope sighted in on somthing go to the range start at 50 Y