ok got into this big conversation with father and brother in law over the point of impact and magnification.... i tried to expain to them ffp and sfp but it was like talking to the wall, their idea was that if you zoom in at full magnification your point of impact would be off by a lot.... i told them that isnt necessary true ... that scope quality is a big factor....they werent hearing it they say that if you zero at 6 power ( remember these guys use 3-9 hunting scopes) that if you zoom in to 9 that any little movement will shift your point of impact by a few inches... then i told them i zero my 4-16 at ten power and just call it a day and when asked what if you need to zoom in more i say i never had to the glass quality i have lets me see pretty far... so is there some truth to their argument or is this just some hunting myth....... you should see their faces when i tell them i adjust my turrets all the time.. the response i get is.. you cant be moving them then you will have to rezero your rifle...yeah
Rifle Scopes does magnification affect zero
- Thread starter colscar
- Start date
Adjusting the magnification "should" have no effect on zero. Now your reticle will be effected depending on if it is FFP or SFP. FFP will adjust the reticle based on the magnification so that your hold over marks are correct for the magnification. SFP will not make this adjustment so your hold over marks will only be good for one magnification.
Most basic hunting scopes are SFP but that really doesn't matter much seeing as there are no hold over marks on the reticle.
This can easily be proved by taking one of their rifles to the range and firing a group with rifle at 3x then shooting the same spot set at 9x. Make sure to have them shoot so they don't accuse you of cheating somehow.
Most basic hunting scopes are SFP but that really doesn't matter much seeing as there are no hold over marks on the reticle.
This can easily be proved by taking one of their rifles to the range and firing a group with rifle at 3x then shooting the same spot set at 9x. Make sure to have them shoot so they don't accuse you of cheating somehow.
Myth... Your cross hair indicates center no matter what magnification setting you are on or zero on. POI will not be affected if you have a properly functioning optic.
What is affected by different magnification settings are the subtensions of your reticle in a second focal plane optic; First focal plane optics are unaffected.
If you're using a plain vanilla optic with a duplex cross hair, then who cares what zoom you're on...
What is affected by different magnification settings are the subtensions of your reticle in a second focal plane optic; First focal plane optics are unaffected.
If you're using a plain vanilla optic with a duplex cross hair, then who cares what zoom you're on...
Your zero shouldn't change no matter what power you zeroed it on. Lots of lower end and even some middle of the road scopes suffer from a POI shift when changing from low power to high power. Most times it's either not enough of a change to notice or its not noticed due to most SFP scopes being used at full power all the time which is usually what power it is zeroed in at anyway.
The answer is yes and no.
Optically no in a quality scope BUT in practical, yes and maybe. Those basic 3-9 hunting scopes are parallax set at 100 yards usually so when a hunter/shooter zooms to 9 power and takes a long shot and does not keep his eyesight in line with the optical center of the scope and shoots he will inevitably be off.
Optically no in a quality scope BUT in practical, yes and maybe. Those basic 3-9 hunting scopes are parallax set at 100 yards usually so when a hunter/shooter zooms to 9 power and takes a long shot and does not keep his eyesight in line with the optical center of the scope and shoots he will inevitably be off.
If it does you need a better scope. That is the simplest answer I can think of.
This. I have experienced it in high end scopes. Two S&B's I had suffered from a POI shift going through the mag range. It was minimal (.1mil) and consistent on both scopes but at distance I certainly a had to take it into consideration.
The answer is both yes and no.
In FFP scopes it is virtually impossible to have POA shift with magnification. I say virtually because it is possible in really crappy scopes due to workmanship issues, but for any half-ass decent FFP scope it is not an issue.
In SFP scopes, there is ALWAYS some POA shift with magnification. In quality scopes, that shift is so small that you can not measure it or observe it without specialized instrumentation. However, even in good scopes it shows up occasionally due to QC oversight. When I test SFP scopes, I always check for that.
In the past, this problem was more common that it is now, so your family members are not entirely off base.
Same for turret adjustments: they are a lot better now due to market pressure. I'll give you an example: I am right now setting up a rifle for a friend of mine and he has an old Leupold Vari-X scope that he wants to use on it. If you adjust the turrets on it, the POA will shift after the first shot or two. Alternatively, I can whack it with a mallet to achieve the same settling effect.
ILya
In FFP scopes it is virtually impossible to have POA shift with magnification. I say virtually because it is possible in really crappy scopes due to workmanship issues, but for any half-ass decent FFP scope it is not an issue.
In SFP scopes, there is ALWAYS some POA shift with magnification. In quality scopes, that shift is so small that you can not measure it or observe it without specialized instrumentation. However, even in good scopes it shows up occasionally due to QC oversight. When I test SFP scopes, I always check for that.
In the past, this problem was more common that it is now, so your family members are not entirely off base.
Same for turret adjustments: they are a lot better now due to market pressure. I'll give you an example: I am right now setting up a rifle for a friend of mine and he has an old Leupold Vari-X scope that he wants to use on it. If you adjust the turrets on it, the POA will shift after the first shot or two. Alternatively, I can whack it with a mallet to achieve the same settling effect.
ILya
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This is true about tracking. Most hunting scopes as in true hunting scopes where not made to take lots of up and down or side to side adjustments due to being they are made to just set them up to a zero point and after a few taps from a mallet to settle in then they need to be left alone. Higher end scopes are made for constant adjustment and still retain zero. So you are spot on about that ILya.
And also very true about FFP vs SFP and what happens during magnification.
was looking for you to comment on this.....
does magnification affect zero
FFP scopes can have reticle jump. SFP scopes can have slightly different points of impact with a magnification change due to the reticle being in the second focal plane. Neither should be enough movement to force a shooter to compensate for it. And that said, if you ever have to tap your scope with a mallet to 'settle it in' the scope is broken.
FFP scopes can have reticle jump. SFP scopes can have slightly different points of impact with a magnification change due to the reticle being in the second focal plane. Neither should be enough movement to force a shooter to compensate for it. And that said, if you ever have to tap your scope with a mallet to 'settle it in' the scope is broken.
Graham I'm talking about cheaper end scope. High end scope I have never had issues with of any sort of things mentioned in this thread.
Tell that to Lueppy...
does magnification affect zero
I can't even tell them to use a proper elevation knob spring.
well the main argument was if you aim at low power and say your not steady youll miss small opposed to if your aiming with a higher power and you are not steady the miss will be large.... i say if your not steady thats your first problem...... the example given was if you look at a grid at low power and move one inch left will you move the same distance if you were at a higher power.. my father in law is one of those that im always right so relativity and physics are out the door with him and his experience rewrites all the laws lol
I've got a Zeiss 3-9x40 Conquest that is a SFP scope and I have noticed what I think is a POI shift with same POA with a change in magnification. That was on a factory built Rem 700 ADL though so once it comes back from LRI I will test it again to see how bad it really is. It was hard to tell with the factory built gun if it was the scope moving or the gun POI shifting.
Uh, NO.
If you are not steady, your wobble with be some angular amount. Say you have 1 MOA wobble, you will increase your group size by 1 MOA. No matter what power the scope is set at.
You will not SEE the wobble as much at lower power. But the wobble is NOT dependent on what you are seeing.
For original poster- this is the case including all manufacturers. I know max allowed SFP POI shift as an fact for only one high-end manufacturer, but all share same basic problem.
For original poster- this is the case including all manufacturers. I know max allowed SFP POI shift as an fact for only one high-end manufacturer, but all share same basic problem.
This "jump" is possible with SFP reticle too.
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