BDC turrets are a marketing gimmick. I hate to say that it's marketing for the masses that don't know better, but it kinda is, especially for longer range shooting. The marketing has been done very well and now it seems like every scope manufacturer out there is making BDC reticles or BDC turrets.
That's putting it a bit strong. While some companies' marketing has gone too far and glossing over their limitations doesn't do anybody any good, that's the fault of the companies, not the turrets themselves. Anything that not only works, but works exceedingly well when properly used is not a gimmick.
The limitations depend upon what you're shooting and how far. The higher BC bullet you shoot and the faster you shoot it, the farther you can go before you need to worry about day to day weather changes. A .308 or similar shooting a medium BC bullet will need real time weather measurements and dope corrections at ranges where an Ultramag shooting a high BC bullet can completely ignore them. General rules of thumb for the former only apply to the latter at much longer ranges. Many or even most here would consider 750 "medium range," especially for a 338 RUM. In fact, I'd say to the contrary that suggesting a PDA is needed for this application is silly.
Most of my shooting, with different rifles, different scopes, different loads, different locations, different times of the year, etc, is dialed the standard way directly off the laptop or from a freshly printed drop chart for that day. Yes, it works.
But when I nail down the variables and make up a BDC turret, there's no doubt I'm much, much, faster, less error prone and simply more effective to 900-1000 yds, especially when under time pressure. Inevitably when I eventually take it off for whatever reason, having to go find a number in another chart somewhere bugs me. For use at 1000+ sure (for a big gun, closer for smaller), but when it's not needed having to go to another chart or run a number on a computer adds no accuracy, adds no value; only time and inconvenience.
Again, I'm just saying don't blame the tool when it's used incorrectly, it's not the tool's fault. But any tool that works so well when used properly is not a gimmick. In fact, I can't think of a single good reason
not to use one in the manor I do. It adds a great deal for the 90% of likely situations, and having the MOA/MIL numbers on as well means it won't take anything away if the 10% comes up.
Though as I've said many times before, one shouldn't try and use them as a substitute for the simple skills and knowledge of ballistics/trajectory and dialing to compensate. One should needs to learn these things. If you don't understand how your tool works, you're likely to misuse it one day--you won't understand what the limitations are and why they are what they are.
