Re: SWFA 1-4X SS
I didn't mess with the BDC, that will all be changed anyway. But to your point, you are correct that a BDC reticle is only going to be <span style="font-weight: bold"><span style="font-style: italic">exactly</span></span> on for a specific load in specific conditions. But how this affects your actual use depends upon what you expect from it.
If you expect precision first round hits at 700 yds, you'll probably be disappointed unless everything is 100% perfectly calibrated. But that's not really what this scope is intended for.
If what you actually plan on using the BDC for is center of mass hits out to 400 or even 500 yds if the ammo even relatively close, a BDC reticle can work for a very wide variety of ammo and conditions and get that done keeping the POI within 1"-2" of your point of aim.
The trick when using ammo that doesn't match is to zero it at 300 yds with the 300 yd mark of the BDC. This drives the large angular errors in the difference in the trajectory curves to 100 and 200 yds where they don't matter nearly as much (smaller linear errors) and makes you much closer at 400 and 500 than if you had zeroed at 100 yds.
I'm usually not a fan of BDC reticles for most applications, but I've got a 4X ACOG with the JP reticle which is calibrated for 77 SMK's and there is just nothing I've seen that's faster for banging steel from 100-500 yds. I'm currently using 73 Bergers but that reticle will be OK with anything from 62-80 grains out to 500 on paper plate sized targets using the method above. Of course if I loaded 40 grain varmint bullets at top velocities or something, it would be way off. But who would varmint hunt with a 4X scope? Most who use this scope will be using something at least 62 grains+ at fairly moderate velocities.
600 yds is a different story. I find this is where differences begin to get drastic for the 5.56 (and 7.62 sized rounds for that matter) even for somewhat similar loads. That goes back to keeping expectations realistic. An AR with a 4X scope isn't the best tool for that in the first place, but if somebody wants to do it he should really know his dope and dial.
Anyway, those are my thoughts. I think for many people if they can nail plate sized targets easily out to 400 or even 500 yds they'll be thrilled. While I'm not a BDC reticle fan either, I think it could be more useful to many of the buyers than some may be giving it credit for.
And in the end, Chris has said they're going to make both types so it shouldn't be an issue either way for anybody. For those who don't like them, get the simple mil reticle. The scopes have very nice turrets and tracking has been perfect in my tests so you can certainly dial to whatever precision you are capable.
On a related note, have you actually chronographed M855 out of those barrel lengths? I haven't but have seen reports of velocities much lower than that.
