How difficult is it to change the parallax on older fixed power scopes? Is this something that must be done at the factory,or can it be done by yourself? I am getting an older Bushnell Banner 2.5 X20 made in Japan that I want to use on a .22 with most shooting done under 50 yards.If the parallax is set at 100 yards,will there be any appreciable difernce shooting it at 25 yards? Is it just best left well enough alone rather than risking damage to the scope by messing with it?
Adjusting parallax
- Thread starter ratherbefishin
- Start date
Willy Tincup
CGN frequent flyer
- Location
- Owen Sound
If its a 2.5 x 20mm scope it was intended as a .22 scope and probably has the parallax preset for 50 yds. I would wait till you get your hands on it and check it out then.......wTc.
I've adjusted a couple of .22 scopes to parallax correct at 100 yards. Loosen the locking ring on the objective lens then turn the objective lens to correct the parallax. Re-tighten locking ring. Warning however, if you remove the lens you could let in outside air.
Scopes are not necessarily air tight but completely removing the lens could compromise the inert gas causing fogging etc.
Do this with the firearm locked down and aimed at the target at the range you want. Not suitable if you keep changing your range distance in which case get a scope with a parallax adjustment.
Scopes are not necessarily air tight but completely removing the lens could compromise the inert gas causing fogging etc.
Do this with the firearm locked down and aimed at the target at the range you want. Not suitable if you keep changing your range distance in which case get a scope with a parallax adjustment.
I think they are all effected the same way. Easiest way is lock the scope down and aim at a point at different ranges.
Move your eye/head around while looking through the scope. At the set range the cross hairs won't move.
Mine are 4x and 3x-9x and I have adjusted both. They were originally about 65-75 yds and huge groupings at 100 yds. Once they were set for 100 yds the groupings tightened up. I shoot at the club at 100 yrds so it's worth doing.
Just watch the threads as you adjust the objective lens. I think if you are going to a shorter range for parallax the objective lens will go in and it won't take too many turns. If you are trying to go for a huge range difference then it may be less possible to do. Most large bore scopes I think are set to 100yds/mtrs but if you are going from 65 down to 25 it should be doable.
Move your eye/head around while looking through the scope. At the set range the cross hairs won't move.
Mine are 4x and 3x-9x and I have adjusted both. They were originally about 65-75 yds and huge groupings at 100 yds. Once they were set for 100 yds the groupings tightened up. I shoot at the club at 100 yrds so it's worth doing.
Just watch the threads as you adjust the objective lens. I think if you are going to a shorter range for parallax the objective lens will go in and it won't take too many turns. If you are trying to go for a huge range difference then it may be less possible to do. Most large bore scopes I think are set to 100yds/mtrs but if you are going from 65 down to 25 it should be doable.
Just be cautious with the spanner you are using to release the objective locking ring...both the ring and the glass will react badly to a ham fisted approach. FWIW ... some of those locking rings are held in place with an adhesive and can be hard to budge ...
