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Posted: 5/25/2007 11:55:01 AM EDT
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Noob Question: On a 4x16x40 variable scope, assuming dead center aim on both shots and same distance. Will the shot zoomed in at 4x hit the exact same spot when zoomed in at 16x? 'After' you answer I give you permission to make fun.  
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It's a good question. In the early days of variable scopes, point of aim shift was definitely an issue that affected the cheaper scopes and even some of the more expensive ones, but over the years this was corrected and the issue has mainly gone away or the effect is too small to make much difference. |
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European scopes are usually the ones that have the reticule in the first focal plane. The problem with that setup is that as you increase the power of your scope, the size of the reticule will increase; the wires will thicken and may blot out the target. Some people find it disconcerting to have a reticule change size with zooming. American (and many (most?) non-European) scopes commontly have the reticule in the second focal plane and this allows the reticule to remain at a constant size regardless of the power setting. The downside of the reticule in the second FP for mil-dot scopes is that only one power setting will work for ranging with the mil-dots, usually the highest power of the scope. In the past there have been issues with shifting points of aim because of varrying power settings, but those have been pretty much eliminated in the last few decades due to CNC manufacturing and quality control. FFP and 2FP have their adherents with their own reasons for choosing either. I don't think one is better than the other, just different and depending on your needs, you just select properly. For target and varminting, the second FP may be preferable because of the need for a thin reticule due to the size of the targets. I prefer the thinnest reticule possible, but I only punch paper. |
Just to be clear the zero does not shift in a FFP reticle while zooming. There is ZERO zero shift. That was not so clear the first try.  You can only range at max power if you dont have a FFP reticle. The FFP reticle also does NOT grow to blot out the target. It remains constant relative to the target and grows or shirks with teh target as mgnification changes. As you decrease magnification in a SFP scope the crosshairs stay thick but the target shrinks. Only a SFP reticle can make the crosshairs so big they blot out the target if they would not have otherwise at high magnification. |
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One simple answer, not easily. If it is important to you to use mil-dot ranging all the time and at any power setting on your scope, then don't even look at SFP scopes, go to FFP scopes. I use a fixed power scope for competition and it has absolutely nothing on the very fine crosshair reticule except for a 1/8 MOA target dot. The scope I had before was excellent but simply did not have enough power. I left it at the 10X setting, but it just wasn't enough. However, I was not kidding about the disconcerting effect of the reticule in an FFP. If the reticule is fine enough so as to not blot out the target when powered down, it may become too fine and be difficult to see under some lighting conditions at maximum power. But overall, if you are mil-dotting constantly and in need of a BDC for every shot, then as I said, go for the FFP; given those requirements, I would. It was a great question. |
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