First focal plane or second focal plane scopes, what to buy?

[cobber]

Looking at an ACSS scope for my AR to replace the red dot. The ACSS scopes look interesting, but there's a fundamental decision to make, whether to go FFP or SFP. It would seem that the FFP is preferable although more expensive. What are the practical pros/cons from any users out there?

 

[Maverick30]

Personally, I don't know of any advantages a SFP scope has over FFP. In case you're unaware (apologies if this is known information), the difference between the two is where the reticle is located in the tube of the scope. With SFP scopes, the reticle is the exact same size throughout the magnification range HOWEVER the downside there is typically the measurements on the reticle are only good at a single magnification level, usually highest power so trying to use hold overs at any other magnification get tricky. On FFP scopes, the reticle is smaller at the lowest magnification and gets bigger as you zoom in. Downside there is low power shooting can be a little tricky due to the small nature of the reticle (depending on the design, ACSS shouldn't be an issue though) but it pays off because say there's 1mil gaps between the lines on the reticle, that 1mil gap is the same at say 6x that it is at 18x making range identification, hold overs, and any other measurements much easier. All of my magnified optics are FFP for this reason. I've got a Bushnell ERS 3.5x-21x on my long range bolt gun, a SWFA SS 1x-6x on my AR, and an Athlon Argos BTR 6x-24x on my NRL22 bolt gun.

 

[cobber]

Personally, I don't know of any advantages a SFP scope has over FFP. In case you're unaware (apologies if this is known information), the difference between the two is where the reticle is located in the tube of the scope. With SFP scopes, the reticle is the exact same size throughout the magnification range HOWEVER the downside there is typically the measurements on the reticle are only good at a single magnification level, usually highest power so trying to use hold overs at any other magnification get tricky. On FFP scopes, the reticle is smaller at the lowest magnification and gets bigger as you zoom in. Downside there is low power shooting can be a little tricky due to the small nature of the reticle (depending on the design, ACSS shouldn't be an issue though) but it pays off because say there's 1mil gaps between the lines on the reticle, that 1mil gap is the same at say 6x that it is at 18x making range identification, hold overs, and any other measurements much easier. All of my magnified optics are FFP for this reason. I've got a Bushnell ERS 3.5x-21x on my long range bolt gun, a SWFA SS 1x-6x on my AR, and an Athlon Argos BTR 6x-24x on my NRL22 bolt gun.

Thanks. Looking at a LPVO in the 1-8 range. Seems like the SFP would limit the usefulness of the scope, unless you were planning on shooting at maximum magnification all the time. Unfortunately, my vision is just too crummy anymore to shoot without some enhancement. Sad...

 

[Wanderer]

I'd prefer SFP for a typical LPVO. My Kahles K16i (with the SM1 reticle) is a SFP 1-6 and the horseshoe-dot is very large at 1x and makes for very quick target acquisition at close range (the very generous eyebox helps, too). Most FFP LPVOs have a rather tiny reticle at 1x, which may not bother some people but others may find it less than ideal. I would reason that with such a relatively low max magnification, if I'm shooting at a long enough range to warrant using the holdover subtentions on the reticle, I'll inevitably be at max magnification anyway.

 

[Maverick30]

I'd prefer SFP for a typical LPVO. My Kahles K16i (with the SM1 reticle) is a SFP 1-6 and the horseshoe-dot is very large at 1x and makes for very quick target acquisition at close range (the very generous eyebox helps, too). Most FFP LPVOs have a rather tiny reticle at 1x, which may not bother some people but others may find it less than ideal. I would reason that with such a relatively low max magnification, if I'm shooting at a long enough range to warrant using the holdover subtentions on the reticle, I'll inevitably be at max magnification anyway.

Valid points. My 1x-6x SWFA has a donut style reticle at 1x with a small crosshair in the middle and when you zoom in to 6x the *donut* portion disappears and you're left with a clean reticle with all your holdover measurements.

View attachment 88482

 

[Wanderer]

Valid points. My 1x-6x SWFA has a donut style reticle at 1x with a small crosshair in the middle and when you zoom in to 6x the *donut* portion disappears and you're left with a clean reticle with all your holdover measurements.

View attachment 88482

Yep, that does appear to be a good solution for FFP. I believe some of the Eotech Vudu FFP scopes do the same thing, using the classic Eotech "donut of death."

 

[russc2542]

Something else to consider is what distance and use the scope will see. If you aren't moving distances where you need to figure holdovers or adjust it on the fly, it's less of an issue.

Yes, with FFP the reticle's bigger and hard to see the subtensions when at low zoom but at low zoom you also usually don't need them because whatever you're shooting at is closer.

I prefer FFP for the record.

 

[Sigblitz]

On my 308 Remington, I use a ffp with a 20 moa to extend the range of my scope. I wouldn't expect to benefit from a ffp at shorter distances, so I have a 1-4 sfp for AR use.

 

[Sigblitz]

But I prefer a bright 2 moa dot in a slim housing that doesn't obstruct vision outside the housing. So I also don't use flip up covers.

 

[JeepHammer]

I have to start with,
1. I'm mostly a long range shooter, so high end optics,
2. Red Dots' obscure fairly large portions of the target.
3. I'm over 40, so my eyes have flattened out.
4. I have astigmatism, so 'Red Dots' often have a halo around the dot itself, obscuring the target even more.

First Focal Plane isn't a huge deal until you shoot variable distances, particularly when exact ranges are unknown.
FFP allows the range estimation to scale with magnification, allowing better range estimation.
The optics are more complicated, so more expensive, particularly when built to withstand a heavy beating (like it might get in battlefield conditions).