VX-2 POI change with magification change

N

Nipigon Jack

Regular
Rating - 100%
32   0   0
Location
Brantford
I recently purchased a VX-2, 3 x 9 x 40 scope and mounted it on a Husqvarna full stock 30 06 that I picked up about a month ago.
I chose this scope as it was the only gloss scope that I could find in stock. Yes, I'm a fudd, and felt that nothing but a gloss scope would do. Today was the day to get this to the range and get sighted in for deer season. I'm not necessarily going to carry this rifle, but I want to have it ready just in case.
With 3 shot groups in the three quarter inch range an inch high at 50 yards, I thought I was ready for 100 yards. Once I got to the hundred, I cranked the magnification up to 9 to get a good bead on the target.
Now I'm hitting 2 to 3 inches higher. Am I getting a shift in POI with the magnification change?
I'm expecting a bullet to drop at a 100 compared to 50 yards. Am I totally not understanding the ballistics?
If I'm getting a shift in POI, can I eliminate that by upgrading to a VX-3I?

I need to get some of my other rifles out and test for POI shift with them, as I've never noticed this before.
 
Last edited:
Remember your scope is mounted 1.5-2" over your rifles bore.
If your rifle is sighted in to hit 1" high at 50 it will hit even higher at 100 due to the angle between the centerline of barrel and the centerline of the scope.(the bullet is still climbing)(not really but it makes it easier to explain)
I think if you sight your rifle in for 100 dead on you will be hitting slightly low at 50, which is about correct for the rifle scope combination.
I don't think there is anything wrong with your scope.
JMHO
 
Last edited:
Sounds like your not understanding the ballistics. Using the winchester ballistics calculator, for a 150gr 30-06 sp and a 225yd zero
50 yds 0.9 in
100 yds 2.3 in
150 yds 2.4 in
200 yds 1.2 in
225 yds 0 in

I'm not sure what zero you intended but your findings pretty much coincide with a 225yd zero. So nothing wrong with your scope. If this zero is acceptable then your ready to hunt.
 
gunaddict99 said:
Sounds like your not understanding the ballistics. Using the winchester ballistics calculator, for a 150gr 30-06 sp and a 225yd zero
50 yds 0.9 in
100 yds 2.3 in
150 yds 2.4 in
200 yds 1.2 in
225 yds 0 in

I'm not sure what zero you intended but your findings pretty much coincide with a 225yd zero. So nothing wrong with your scope. If this zero is acceptable then your ready to hunt.
Click to expand...

Well that kind of proves that I'm ballistically challenged.
The VX-2 was not the scope I had hoped to get and I guess I was looking to blame all the worlds troubles on my " Its not a VX-3 " scope.

I had my heart set on a VX 3 in gloss and called around to find one. Finally I was told by one of site sponsors that that had a VX3 gloss in stock. So off I went on a 2.5 hour drive to pickup my baby. When I get there I was told they couldn't find it, but that they had this VX2. I have been in a funk about it ever since.
Still not sure if there is any significant improvement in the VX2 versus the VX3. Only thing I really found online is that the VX3 has a locking eye piece.
 
Nipigon Jack said:
Well that kind of proves that I'm ballistically challenged.
The VX-2 was not the scope I had hoped to get and I guess I was looking to blame all the worlds troubles on my " Its not a VX-3 " scope.

I had my heart set on a VX 3 in gloss and called around to find one. Finally I was told by one of site sponsors that that had a VX3 gloss in stock. So off I went on a 2.5 hour drive to pickup my baby. When I get there I was told they couldn't find it, but that they had this VX2. I have been in a funk about it ever since.
Still not sure if there is any significant improvement in the VX2 versus the VX3. Only thing I really found online is that the VX3 has a locking eye piece.
Click to expand...

Don't sweat it, the VX-2 is a fine scope.
 
Sounds like its doing what it is supposed to.

The last upgrade on the VX2s bumped them up a notch in optics and relatively speaking they are a good scope at a decent price. As for comparing with the VX3 or VX3i; put it this way....If the 2s were as good as the 3s there wouldn't be any 3s. Doesn't mean it isn't good enough, only you can decide that
 
In every second focal plane 'scope I have seen the design is such that changing the power also moves the cell containing the reticle. While heavy grease can take up some tolerance and similar or dissimilar metals can be made to move (to effect the change in power) with very tight tolerances -- the tolerances exist by necessity in order for the variable mechanism to operate.... and of course - changes in temperature can affect changes in tolerance. As a result it is pretty much a given that some POI change occurs when changing the power (in second focal plane scopes) ... OTOH first focal plane scopes avoid this mechanical problem as the reticle does not move during a power change - unfortunately the reticle is magnified when the power is increased and any gain made by the fact that the reticle is stable is obscured by the now enlarged reticle which reduces the "fineness" of the aim that can be achieved. etc etc

Fixed power scopes are of course not exposed to these problems .. however all scopes are subject to reticle movement due to recoil, hard impact, scope tubes mounted in a manner where the 'tube' is stressed etc ... In fact a very interesting experiment was conducted years ago where a rifle, with well mounted scope, was held securely in a machine rest - a standard rubber band was placed around the ocular of the scope and the image was observed while the rubber band was pulled perpendicular to the scope - this very small amount of pressure resulted in a significant and observable deflection of the scope reticle against the target image that was being observed. Sometimes the scope remained in the position it had achieved after being pulled with the rubber band -- sometimes it did not - this was attributed to the scope being mounted with stress or not. I am a big fan of Burris "Signature" rings with the self centering plastic inserts for the reason that they allow a scope to be mounted reasonably stress free.
 
I had the rifle back out this morning and shot 3 groups with it to confirm if there was a change in POI with a change in magnification.
New ammo today so the first group was shot at maximum magnification at 100 yards to get me dialed in.
The second group was at the bull at 100 yards at max magnification. I dialed the scope down to 3 power and reshot my last group at the bull again.
My last group landed 2 inches below the first group.
So my conclusion is that this scope does change POI with changes to the magnification.
The only other possibility is my vision just isn't what it used to be and at 3 power, I'm not seeing my target well enough. Next time out I'll have to have a known shooter give it a try and see if they get the same results.

I've got a model 7 with a Nightforce compact on it. I'll run the same test with that next. If I get the same results, then I guess its tome for another eye exam and new glasses.
 
bsand said:
curious and not really sure but figured I'd ask, could the lack of parallax adjustment have something to do with this?
Click to expand...

Its certainly a possibility...generally scope manufacturers will set parallax at approx 100yds....some will set scopes intended for rimfire use a little closer (75yd approx) but it is possible that is not the case with individual scopes. Of course if you keep your eye centered in the exit pupil of the scope... parallax is not a factor.

You 'might' be able to detect parallax 'error' by ensuring that your scope is absolutely stable and while looking at an appropriate target...ie thin dark post at 100m... move your head/eye position back and forth in the scope view/image at the ocular....if the reticle appears to move position against the dark post...that is parallax (to add: at 100m of course)
 
Last edited:
sounds like a parallax error issue to me; as magnification changes, so does eye relief. If you move your head to compensate for changing eye relief your cheek placement changes, most likely moving your eye to scope position vertically, which accounts for the vertical POI change. One of the things that more expensive glass tends to have is a more forgiving eye box, meaning you dont need to adjust your cheek weld as you change magnification. So even if it isnt the reticule moving in the tube, it is very likely attributable to 'lower' end glass, and the VX3 may not have had this issue for you. However, on a hunting rifle such as you have, I think this is likely irrelevant. Sight in at max power: if you are shooting at something far away (over 200 yds) you will probably have the scope on max power, and your POI will be correct. If you are shooting at game on 3x, its probably close enough that a 2 MOA difference wont be a problem.
 
Mount Sweetness said:
Poi won't change with zoom on a VX2 or 3
Click to expand...

Not entirely correct. It shouldn't change, at least not significantly. Sometimes though, due to the points mentioned in AP's post, there will be a minor change. If this change is significantly greater than 1 MOA, and it is verified by a 2nd competent shooter (preferably one that doesn't wear glasses to eliminate eye issues), I would consider the scope defective and have it warrantied.
 
You must log in or register to reply here.
Back
Top Bottom