Tech Question - Scopes

[K22]

With a First Focal Plane (FFP) variable scope containing a starndard duplex recticle does the point of impact change with changes in magnification?

Reason I ask is that for some time I've been using a lower magnification at 100 yards when practicing shooting off my shooting sticks at the range. Then increasing to full magnification at 200 yards (longest distance at my range). For example I dial the magnification down to 8x (1/2) at 100 yards then up to 16x at 200 yards. This does two things for me, it gives me the same target picture at both distances and helps me avoid "chicken finger" at 100 yards because of the increase preception of movement if I use 16x at 100yards. When I hunt I leave the scope set on 16x. In some rough testing I could find no difference but a fellow shooter claims that a FFP scope needs to be sighted at each magnification to be precise. This is contrary to what I've experienced. Help settle the debate. Thanks

 

[JLT]

The POI should not change with a change in magnification. If it wanders as you zoom through the range, there's either a problem with the scope or the design itself is not up to the task.

You mentioned practicing with shooting sticks - if the rifle isn't set up the same way on the sticks, your POI will very likely shift. I would suggest testing the scope off a solid front rest/rear bag set up. If the scope behaves, then the problem lies elsewhere. If the POI shifts materially, then you've identified the problem.

Good luck.

 

[fredo]

...but a fellow shooter claims that a FFP scope needs to be sighted at each magnification to be precise.

 

[Willie]

Baloney!

 

[seymour fish]

With a First Focal Plane (FFP) variable scope containing a starndard duplex recticle does the point of impact change with changes in magnification?

Reason I ask is that for some time I've been using a lower magnification at 100 yards when practicing shooting off my shooting sticks at the range. Then increasing to full magnification at 200 yards (longest distance at my range). For example I dial the magnification down to 8x (1/2) at 100 yards then up to 16x at 200 yards. This does two things for me, it gives me the same target picture at both distances and helps me avoid "chicken finger" at 100 yards because of the increase preception of movement if I use 16x at 100yards. When I hunt I leave the scope set on 16x. In some rough testing I could find no difference but a fellow shooter claims that a FFP scope needs to be sighted at each magnification to be precise. This is contrary to what I've experienced. Help settle the debate. Thanks

No

 

[Paul Seaman]

My welding instructor once told me, "If it's working for you don't worry what anyone else says or think they know!" Just smile and don't let him shoot your rifle!

 

[spaniel]

a fellow shooter claims

This is how all good gun shop legends start...

He doesn't know what he is talking about.