Originally Posted by Clndesl
Ok so I'm going to be ordering a vortex pst 6x24 50mm in mil on mil and I am stuck on whether I should get FFP or SFP. I have never had a FFP so I guess I just wanna know if it's better and worth the extra $. Thanks
How do you plan on using your scope? For instance, do you plan on or have a desire to learn to use the reticle for things like elevation hold over, windage holds, calling shots, or ranging? If your answer is no then you will be just fine with a SFP scope and will save some $$$. If the answer is yes then I would suggest you at least think about an FFP scope. If you answered yes, then do you shoot in conditions where mirage can be an issue? Do you shoot in low light conditions? If yes, then an FFP scope is even more valuable IMO. SFP advocates will argue that you can do the same things with an SFP scope and while this is true there are a number of issues that must be dealt with in order to accomplish the task, where with FFP you don't have to worry about them.
FFP eliminates potential error when using a reticle. This is the main benefit to FFP. Because the reticle subtends the same through the entire power range you don't ever have to worry about miscalculations because you thought you were on the correct power setting when in fact you weren't. Big deal if you shoot in a hurry or under some pressure. That is most of us most of the time IMO. In addition, one must make sure that and SFP scope is calibrated correctly at the designated power setting in order for the reticle to subtend correctly. As an example, most SFP scopes are designed to subtend correctly at a specific power setting, letís say 20x. So a shooter needs to be sure and measure the reticle at 20x to be sure that it really is 1 MIL per hash or 2 MOA per hash etc. If it isnít then that error has to be dealt with for things to be accurate to your ballistic program or chart. Then you must make sure that you get to the exact same setting on the power mag ring to ensure the reticle subtends the same every time.
FFP is also nice if you are shooting during periods with high mirage. Most SFP scopes are designed to be used on high power for the hash marks to subtend correctly. But high power brings out the most mirage issues and sometimes using the highest power just isn't a good option. Of course SFP users can just learn a second set of numbers to use at a lower power setting but that raises the potential for error and makes things more difficult.
In the same line of thinking, using high power during low light conditions may make the sight picture too dim for a good shot. With FFP you can reduce the power and still have the reticle subtend correctly so there is no increased chance for error or trying to remember 2 sets of numbers.
There are also some other minor nuances with FFP that may or may not be advantageous to the shooter. In general the reticle is darker and stays darker through the adjustment range and is easier to see throughout the power range. And this isn't just because the lines are thicker. It has to do with how the reticle is projected to the eye.
For whatever reason there seems to be a lot of guys that have a very negative feeling toward FFP scopes and some have a tendency to give reasons that simply aren't factual. Many times when I inquire about their experience with FFP scopes I find out that there is little to no experience. So some things to keep in mind.
* With any of todays mid to upper end FFP reticles, there is no issue with the reticle being too thick for precise shooting. The technology used to etch the reticle on the glass has gotten very good and manufacturers have found the proper balance between precision and visibility.
* The reticle size does not grow when magnification is increased. It stays the same size throughout the adjustment range. So if the reticle gives you enough precision to make a shot at 3x it is going to give you the same precision at 20x. What SFP will do for you is actually increase the size of the target in relation to the reticle. Some guys find more confidence in this concept and therefore like the SFP better but it is important to understand that FFP won't worsen with magnification, it stays the same. If I were shooting groups in competition or shooting smaller targets like ground squirrels at LR then I would look at SFP because it does allow you to get a bigger picture of the target in relation to the reticle. But I had the SS 3-9x40 FFP on my 17HMR and wasn't having any issues hitting little Belding ground squirrels out to 300 yards.
*Ranging is often incorrectly listed as the only benefit to FFP scopes when in fact it is the least important. Things like, holding for elevation, holding for wind drift, and calling corrections (how far off center your shot was) are far more widely used and are much more valuable. Just being able to call misses in MILS or in MOA while practicing is a huge asset. It helps you develop a mental picture of what is happening downrange and gives you a way to quickly call the error, adjust for it and get another shot off. This in comparison to having someone call the miss in inches, which will be a total guesstimate, then trying to work the numbers backwards to find out how many MOA you need to adjust for a 17 inch miss at 575 yards. Way too much time and math when instead you just could have read through the reticle that there was a 3 MOA miss to the right. Then you hold or dial the 3 MOA and you are ready to shoot again. Very quick, very easy!
Hope This Helps,