POI and POA change

German pointer

Anyone having poi poa change in sfp mid priced scopes when using various magnifications especially the sidewinders

FISMA

German pointer wrote: »

Anyone having poi poa change in sfp mid priced scopes when using various magnifications especially the sidewinders

No, however, I do tend to sight in on a particular magnification and leave it there. Rather than zoom the scope.

Also, I am not doing precision target work, rather hunting, plinking, bunny bashing, and the like. If there was POA variance due to zoom, I may have missed it.

True, I have heard of this issue in ffp scopes. But, I really doubt if mid range scopes would have this as a serious problem.

This is one of those times where I start to think about a fixed magnification.

Cass

No.

Been at the range today and from 8 power to 22 power at 100 and 200 yards no shift in POI to POA. Hawke Sidewinder 30 used.

German pointer

Cass wrote: »

No.

Been at the range today and from 8 power to 22 power at 100 and 200 yards no shift in POI to POA. Hawke Sidewinder 30 used.

Thanks that's what I was expecting and hoping to hear

hrcbob

I have a hawke night eye that i bought secondhand that has that problem..

As the zoom is increased the crosshairs creep upwards a fraction.
it doesnt loose zero once set at a given magnification so i just set it up at 12x and leave it there, beyond 16x it gets a bit blurry anyway so no great advantage.

it was cheap as chips and the illuminated crosshairs come in handy under the lamp so i can live with the small prob.

Cass

The Crosshairs creep forward? Is it SFP? If so it shouldn't "move". If it is FFP it might seem like it's creeping forward but this is normal for a FFP scope.

One shot on kill

I've a sidewinder and never noticed anything like that.

EWQuinn

I finally had a problem rifle shoot consistent groups (like 7 test groups in a row) at 200 yd (the zero range). Then I made a slight windage adjustment (1MOA) and the groups openned up. Not sure but I am hoping that it was the barrel getting dirty or just getting too hot. It is a good quality scope, Leupold 12X. Scope mount and screws are tight. Doesn't seem like it should be the scope.

Longranger

I've a sidewinder and have hunted from 50-300+ yards at almost all zoom levels and never had a problem.

Jonty

EWQuinn wrote: »

I finally had a problem rifle shoot consistent groups (like 7 test groups in a row) at 200 yd (the zero range). Then I made a slight windage adjustment (1MOA) and the groups openned up. Not sure but I am hoping that it was the barrel getting dirty or just getting too hot. It is a good quality scope, Leupold 12X. Scope mount and screws are tight. Doesn't seem like it should be the scope.

Action screws on rifle maybe?

One shot on kill

You hardly moved the scope back that 1 MOA to see if the groups tightened Back up.

EWQuinn

Action screws were tight. I ran out of ammo and barrel getting a little fouled, also could have accumulated a little heat by the time done shooting. I cleaned her up and will take the optimal load back out. Yes I will reset the scope to the original setting and try the experiment again. Thanks

Cass

EWQuinn wrote: »

Then I made a slight windage adjustment (1MOA) and the groups openned up.

Did you dial back the 1 MOA?
If so did it correct the problem?

Whenever a problem presents you should always look at the last thing you changed, adjusted, added, took away.

Not sure but I am hoping that it was the barrel getting dirty or just getting too hot. It is a good quality scope, Leupold 12X. Scope mount and screws are tight. Doesn't seem like it should be the scope.

Not to piss on your parade, but ya never know. Even good scopes can go bad.

Groups opening up can be a number of things. From loose screws on the rings, to improper torque settings of the barreled action, to a damaged/faulty scope, over heating, poor ammo (batch), excessive fouling, loose mod (if you use one), improper hold, breathing, etc, etc.

Try eliminate the mechanical issues first then work on whatever is left.

Can you give us a run down of your set up. From rifle to rings, scope, ammo, firing position, time between shots, cleaning frequency/method, etc. Also an idea of groups at 100 then at 200.

EWQuinn

Cass, your response is appreciated and that is what I fear. In that small scope adjustment the adjusting screw was VERY stiff, like I had to fight it to move one MOA. I went right from the range to the ordeal of trying to plant grass in the midst of a drought in a very small window of opportunity with very challenging soil & climate. So I have been working the land by hand as it were, and no time to fully take stock of results and report properly (in addition to the usual work crap). I'm not a grass freak, just don't like living in a dust bowl.

When I have time I will respond more appropriately, but before I go further I have a confession to make, the rifle in question is a Ruger No 1 :eek:

Cass

EWQuinn wrote: »

In that small scope adjustment the adjusting screw was VERY stiff, like I had to fight it to move one MOA.

I would be looking at the scope. Quick story.

A mate a few months ago had a similar problem. However he could not get a proper group at any distance but it did "group" better at one distance over the other. I was spotting for him and no matter what he did the groups would go from 2" to 7". He had the same stiffness in his turrets.

Turns out the scope turret was trying to adjust a faulty aligned/placed lens inside the scope. At a certain adjutment the lens was under little to no pressure (somewhere near mechanical centre of the scope) but when he tried to adjust it he was trying to make the lens move in a way it could not go.

Picture trying to push a train from a set of tracks where it rolls smooth and fine, off them, and through some gravel. He sent the scope off, had it repaired and it came back working fine.

The issue it seemed to cause was the adjustment he made via the turret was not move or move very little when he adjusted it. When he fired the lens would "jump" within the scope housing. The further out he shot the larger this difference in POI would be as the movement of the lens would be exaggerated at longer distances.

Now this is only a theory. It could be something as simple as the rifle crown is poor or damaged. You using a bad batch or wrong type of ammo. Is the scope housing touching the barrel? What weight is the trigger? Are you flinching/pulling?

There is just so much without knowing how the rifle shot previously. Or has it done this since you put the scope on?


A good way to test it is to change scopes. If a new scope does is mounted and eliminates the issue then look at the scope. If not then it's the rifle/ammo. You need some sort of process of elimination to determine the cause.