Rifle Scopes Second focal plane
- Thread starter fresno
- Start date
I think people more likely than not are going to have a second focal plane on something. I know my hunting rifles all sport them, it wasnt a conscious decision, its just what it was/is. They are lower powered, the highest tops out at 14x so I shoot them on max power almost exclusively.
If youre worried about the reticle subtension scaling with magnification, its not that detrimental. Just remember if you are on half power they actually represent twice the given value.1/2 power is 2x as much 1/4 power is 4 times as much. Ex: a 1 moa hash on the reticle @ 12x would actually represent 2 moa at 6x would represent 4 moa at 3x
Some scopes have their reticle subtentions scaled out at something lower than max power. A vortex hs-t 6-24 has its reticle subtentions at 18x. Just have to read the manual to know for sure what a specific scope is set at.
If youre worried about the reticle subtension scaling with magnification, its not that detrimental. Just remember if you are on half power they actually represent twice the given value.1/2 power is 2x as much 1/4 power is 4 times as much. Ex: a 1 moa hash on the reticle @ 12x would actually represent 2 moa at 6x would represent 4 moa at 3x
Some scopes have their reticle subtentions scaled out at something lower than max power. A vortex hs-t 6-24 has its reticle subtentions at 18x. Just have to read the manual to know for sure what a specific scope is set at.
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It depends: if the generic 4-16 in question says that it subtends accurately at max power, max power being 16, then at 8x it would be half. But say that scope actually subtends correctly at 14x instead of 16 then half the value would be at 7x. Generally scopes will subtend at full power for the vast majority out there. Some of the higher powered or just odd balls are different which is why I said you just need to see what each particular models says in the manual.
If you throw out some of the particular models youre looking at we should be able to get you a more definitive answer.
If you throw out some of the particular models youre looking at we should be able to get you a more definitive answer.
Assuming subtensions are true at full power, half of the max zoom is where the values double.
I have two custom rifles and both have 2nd ffp scopes on top of them. But I have a third custom rifle on the way and I'm going to buy a FFP scope for it just because I don't have one. But as far as 2nd ffp goes don't worry about it. If you miss five tick marks to the right, don't worry about what power you're on, just move your point of aim five tick marks to the left. The only time it matters is when someone is spotting for you and calling corrections. If they call a correction of 1 moa left. then you have to know what power you're on to know how much to move, but if you'll write it down on a card or something you'll be OK.
I bought an SFP scope for my first rifle to shoot PRS style matches. Worked fine at high power, but then I couldn't use it at high power in July due to mirage. So, then I reduced magnification which isn't a problem, but then what is the correct wind call. If you dial it you're fine, if you're holding is it double what you actually see in the scope or 1/3, or something else? All my scopes are FFP now, haven't had an issue while hunting yet.
Its accurate at top mag, page 3/4 under reticle options
http://www.vortexoptics.com/uploads/manual_rfl_pst-2p-web.pdf
You guys can stone me to death for this but...I prefer a SFP for long range shooting- specifically the NF MOAR-T/NPR-1. To be clear I don't shoot holdovers and I only "mil" targets occasionally and always follow up with ranging with an LRF. The NF MOAR-T is 0.0625moa wide at full magnification vs.0.1 MOA (I believe) of the MOAR. At full magnification (again, where I spend the vast majority of my time) I get a finer aiming reference. The MOAR-T reticle is not available from NF on there FFP scopes as the reticle would be to fine at low magnification to be useable. FFP are very desirable for people who use holdovers at a variety of magnification or need to routinely "mil" targets-especially at a variety of magnifications.IMHO.
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My latest NF optic is a SFP with 10x on the top end and I love it. If I need hold overs, then the mag is already cranked to 10.
Same here.
Razor Gen II 1-6 and Bushnell ET 1-6.5(s) all SFP.
Every other scope I own is FFP.
As for the "SFP at full power has a finer aiming point" argument, get an FFP with a floating center dot.
Yep, nice to see the reticle on low power for carbines that I won't be shooting past 600Y much anyway. 1x for close, 3x for coyotes at normal distances, etc, and 6x for occasionally farther out and where I might holdover and holdoff with subtensions being correct.
12x and up FFP.
If I was shooting known distance targets and mainly concerned about getting the smallest groups possible, I'd go with a SFP reticle.
I picked up a ffp scope to experience the hype. As typical, at least for me, when I want to hold at the far reach of the reticle, I want to max the magnification. When I max or even get close, the portion of the reticle needed for hold is gone. So, with my ffp scope I can use the reticle at longer range with minimal magnification or shorter range at greater magnification. I don't care for it. Couple this with Mills and fuck the whole thing.
SFP scopes can do the job if you recognize their nuances and learn to use them properly. While the reticle subtension values are not true at all magnifications, if you DIAL ELEVATION AND WIND, the subtension values don't matter. After making the shot, spot your impact and hold to that point on your reticle. The actual subtension value is irrelevant as you're only using your reticle and the graduations as points of reference for the follow up shot. FFP scopes shine if using holds but if you're a dialer, which many casual shooters are, the SFP will work fine, especially if only going 500 yards.
