side focus torture

[dgiannandrea]

I just picked up a Nikon 4.5-14x40 SF Buckmaster. I recall somebody else had a Nikon scope worked on to bring focus in for air rifle use. As the scope is currently designed near focus is 50yds. Can it be modified to focus at 20yds? Does anybody have knowledge about this?

Otherwise, it is a great scope for 40-100yds and a lot lighter than my others. It will be used.

 

[Odoyle]

You can try to adjust the front lens to get closer focus even if you have a side focus.

Bear in mind you Will lose maximum infinity focus distance when you do this so don't adjust it too much otherwise you may not see past 50 or 60 or 100 yards all depending how close you want to focus.

Same goes for NON ADJUSTABLE AO and cheap scopes as well. You may be able to adjust to see closer than the 100 yard fixed parallax.

https://youtu.be/fSR3GCUZTps

 

[BlackICE]

I always thought the decent scopes are filled with "inert" gas or at least dry gas so that the lenses don't fog inside. Doesn't adjusting the front lens break a seal so that gases inside may no longer keep the scope from fogging?

 

[Odoyle]

I always thought the decent scopes are filled with "inert" gas or at least dry gas so that the lenses don't fog inside. Doesn't adjusting the front lens break a seal so that gases inside may no longer keep the scope from fogging?

I wouldn't see why because the scopes with front AO focus threads in and out too.

 

[Odoyle]

Besides that's how the factory corrects parallax to spec after the scopes are already nitrogen or argon filled as a fine tune correction then screws the lock ring in place.

 

[Odoyle]

Start from 5:38 they dunk in water check for leak then continue to add turrets then fine adjustments after that.

https://youtu.be/7EOdTwe0K8o

 

[dgiannandrea]

Odoyle,

Incredible, thanks for sharing your knowledge and the link.
I assume from the conversation that the objective is tensioned against the adjustment ring.

This is going to be so easy.

 

[Odoyle]

So long as it's not lock tited and some may be so just be sure your makeshift tool fits snug and not loose and have good leverage drill hole in the middle of the tool and run a long screwdriver through it to help if needed for added leverage.

 

[Cannonball]

Odoyle,

Incredible, thanks for sharing your knowledge and the link.
I assume from the conversation that the objective is tensioned against the adjustment ring.

This is going to be so easy.

I also have one of those scopes. Can you please let me know how close you got it to focus and what it changed the maximum yardage focus to? I have a couple air rifles coming to me this week and one of the the two scopes I have on order is still on backorder. I’’m not using the Nikon and might put it to use until my Arken SH-4 shows up. Thanks.

 

[Nutcracker]

So long as it's not lock tited and some may be so just be sure your makeshift tool fits snug and not loose and have good leverage drill hole in the middle of the tool and run a long screwdriver through it to help if needed for added leverage.

Exactly , use to be so easy. I did change a few that were glued, but would not recommend. Definitely would not try it on an expensive scope. You know what I mean. 

 

[Odoyle]

YUP my Sightron SIII 8-32x56 with 40 yard minimum focus still in the box (is still in the box)...