dfanonymous
Well-Known Member
- Joined
- Jul 16, 2016
- Messages
- 2,271
No, that is not correct.
In an SFP, a reticle with subtension marks will have these marks represent something at specific magnifications. Well, to be exact they represent something specific at ALL magnifications, it's just that the relation changes for all magnification and it's difficult to remember them all.
So, I will speak about my SFP scope that I use for competition. This March-X 5-50X56 has an MTR-5 reticle with hash marks on the horizontal and bottom vertical lines that represent 4MOA @ 5X, 2MOA @ 10X, 1MOA @ 20X, 0.5MOA at 40X and 0.4MOA at 50X.
Of course, intermediate magnifications make the subtensions on the reticle mean intermediate values, such as 1.33MOA @ 15X.
So I, being an older geezer, usually stick with one magnification, 40X, so that the reticle has a consistent meaning.
The problem isn't just figuring out the relative subtension in sfp per magnification. It's harder to math it then one would think. There's an accuracy issue to deal with in all brands and manufactures of scopes labeled power range. YOUR particular scopes true power range is 5.5673x to 55.6732x even though it's marketed at 5-50x56. Sfp are calibrated for one or two true sub tensions. Everything else is a guess or a lot of preplanned work with several sheets of paper at different power ranges to give you relative sub tension values if trying to get it to work at all power ranges.
If I miss a .5 mil target by 1.2 mils, I want to know I missed by 1.2 mils, not round about. Especially when working in that small margin for error in particular scenarios. You don't have to do all this with a ffp. You're hold is correct, you measurements are correct. One dunt need to worry about hours of figuring out specific reticle and magnification range calibration, or limit yourself to a particular power range to be precise.
I'm being particular to long range.