focal planes

[Richwv]

I am looking o buy a new variable scope and had a question about focal planes. It will mainly be used for hunting right now but someday may hopefully serve double duty asa medium to long range competition scope. I thought I understand the difference but am not sure. A lot of things I read say the point of impact changes at different magnificfations in a rear focal plane, i understand how the holdover dots on a mil dot reticle would change but I don't understand how the center of the crosshairs would change their POI? I like the advantages of a 2nd focal plane reticle not being as large at high mag or small at low mag, but do not want to have to take all hunting shots at the same magnification I sighted it in on.

[ICANHITHIMMAN]

Originally Posted by Richwv

I am looking o buy a new variable scope and had a question about focal planes. It will mainly be used for hunting right now but someday may hopefully serve double duty asa medium to long range competition scope. I thought I understand the difference but am not sure. A lot of things I read say the point of impact changes at different magnificfations in a rear focal plane, i understand how the holdover dots on a mil dot reticle would change but I don't understand how the center of the crosshairs would change their POI? I like the advantages of a 2nd focal plane reticle not being as large at high mag or small at low mag, but do not want to have to take all hunting shots at the same magnification I sighted it in on.

Well personaly I have never owned any quality optic that was not in the first focal plane. I have never had issue with the thicker lines at all. I have 2 Horus Vision, Leupold and a US optics scopes.

The POI does not shift in a second focal plance scope, the substensions change when you turn down the power. Mils are a set distance, but in a second focal plane optic that is only true at the scope highest power setting. when you back the power down the substension changes. You can work around this if you are sufficnetly trained. Does that help at all?

Jon

[kcebcj]

Your point of impact only changes when the distance from the muzzle to the target changes. For instance let's say you sight your rifle dead on at 200 yards while having the power set to 10. Now when you crank it down to 4 and your still shooting at 200 yards' it will hit in exactly the same place just harder to see the bull but you have a better field of view. This holds true for both 1st and 2nd plane scopes.

I would suggest you go to the web site of the scope you are looking to buy and down load the user manuals for both the 1st and 2nd focal plane scopes. They explain pretty well the difference between the two sub tensions. It may get a little technical but it's not brain surgery.

Here is a link to the Viper PST scope user manuals for their scopes. If your undecided maybe these will help. They are at the left at the bottom.

Vortex Optics - Viper PST 4-16x50 FFP EBR-1 MOA Reticle

[MHO]

You will be much happier with the FFP. Good luck. As the previous thread, check out the vortex site. Also the PST Viper is a great scope. Own one and soon will have two.

[Richwv]

Thanks everyone, yes that did help. I understood how any elevation or windage marks on the reticle would change because as I change magnification the space between them would also change. I had just read many places the point of impact also changes and that did not make sense to me. Thanks again for all your help and clearing things up for.

[rjackh]

Originally Posted by ICANHITHIMMAN

The POI does not shift in a second focal plance scope, the substensions change when you turn down the power. Mils are a set distance, but in a second focal plane optic that is only true at the scope highest power setting. when you back the power down the substension changes. You can work around this if you are sufficnetly trained. Does that help at all?

Jon

he said it right

[Mikecr]

As far as function, if you intend to range with a laser range finder and dial your solutions with turrets, go SFP with a simple med-fine crosshair(if you can get it).
If you intend to range and hold-off with reticles, go FFP, and whatever reticle you think you can do both with and still hit a small killzone.

Either way, if you're hunting, don't buy into cheap tactical wannabe junk, but focus on field functions(what you actually need).

Given that armageddon is not upon me yet(I can still buy batteries), I prefer laser ranging, dialing elevation(in 1/4moa), and holding off for wind(in inches). I prefer a med-fine crosshair like NF's CH1, that works perfect in the field for varmints. Not too small/large, and simple.
My solutions are taken from a printed off click card carried along.
I use either MK4 or NXS scopes ~25x.
My hunting guns are atleast 1/2moa cold barrel accurate(for x distance) off a Harris bipod, and I always position myself to within killzone requirements given this accuracy, or I don't take a shot.
This is not Hollywood. I get one shot per groundhog, and I can engage multiple GHs at ~30-60sec intervals with my system, provided situations support it.

I could not range groundhogs with a FFP scope. I could not even see a GH behind the reticle of FFP scopes I've looked through, much less hold-off between hashes with the target aspects GHs typically provide. Maybe that would be different if my targets were pakistanis..