Either you are way over my head here, or I'm at "one beer too many". Could be either one at this point. So...a while back I bought the Nikon P223 3-9X40 scope. Put it on AR #2, and dialed it in on the IMI 69 SMK. Tack driver. I've played with the BDC reticle, and it's very accurate with the IMI 69 SMK. Obviously no windage correction, but one could use the zero-reset turrets to dial that in if need be.
Now the P223 comes in 4-12X40. I'm a fan of magnification at longer ranges. Realistically, my longest shot would be at or less then 200 yards. But "12X" is better than "9X" at that range. so...
The IMI 69 SMK matches up great with that scope, and the Nikon "SpotOn" app is PFM for amateurs like me. Between the scope, the BDC reticle, and the app, I can dial in my shot at anywhere from zero to 600 yards. I've only played with it out to 200 yards, but it's dead-on at that range, so , again...
If you've got a better idea for a 100-400 yard AR-15 scope, send it. What with my experience to this point with the P223, I'd be hard pressed to not go for the 4-12 as an upgrade, and I already have a buyer for the 3-9. And the SpotOn app is a huge plus. No math, just dial in your round and magnification and put the correct dot on target. Sight, squeeze, and watch the round hit where you want it to. That scope, app, and IMI 69's will give you a big head in short order. They work that well together.
You know a lot more about this stuff than I do, so let me know what, or if, you think I should do. Bear this in mind: I own those AR's for one purpose, and one purpose only. I don't hunt anymore. I'm confident that my HD/Patrol AR is set up right for anything out to 100 yards. AR #2 is for anything beyond that, out to say 300 yards. Longest shot I should ever face in real world. If the 3-9 is enough, fine. If not, then I'm leaning towards the 4-12 Nikon.
This is why I love this thread. I can mine the knowledge and experience of those who have already been where I'm trying to get to.
I miss GV here. Cranky, but knows his s**t.
Go Vols.