I may or may not own a semiautomatic rifle in 7.62x51
1) up to 350 yards
2) I may or may not own a semiautomatic rifle in 7.62x51 with an 18'' barrel
never used an acog, or A Y really high end optic options. that's why I'm asking.
3) I've read that the 1x on variable power optics isnt REALLY 1x. That doesnt really concern me as much as being able to be accurate at medium to max range of the firearm's capabilities.
I dont really know. I guess I'd be using this particular firearm for medium to longer ranges.
OK, that helps narrow things down.
The various ACOGs have different magnifications. The 4x was the most common in the military, but the eye relief on those models is very narrow/short (they're basically designed for NTCH Nose-To-Charging-Handle shooting, with 5.56. When used that way, they have a pretty wide FOV at 4x compared to other optics).
There are other ACOGs with different magnification, including the ones I have, which are 3.5x. They're bigger, and weigh more than the 4x versions, but the BDC (Bullet Drop Compensation) reticle and subtensions were designed for 7.62x51, (and also work decently well with 77gr 5.56), AND they have longer eye relief, which is helpful with 7.62x51, vs 5.56.
*** numbered the points in your responses
1) @350 yards, with 3.5x, the target is equivalent to shooting at 100 yards with no magnification. How adequate/comfortable you are with that, is an individual thing.
With a 1-6x LPVO, @6x, a 350yd target will look about equivalent to a target @~58yds with the naked eye/no magnification.
2) 7.62x51/.308 and an 18" barrel. While perhaps not the recommended choice, has enough ft-lbs for even elk sized targets @350yds (recommended 1500 ft-lbs minimum, at target distance).
3) this is optic dependent, but the Razor and Kahles 1-6x definitely ARE 1x. Some other optics (like the one someone else mentioned above) are 1.5x, and even some red dots aren't 1x (IIRC, when I looked through a Trijicon MRO Patrol, I had the impression that it wasn't a true 1x. Either that or the distortion made it seem that way), but I have both Aimpoint red dots, and the Razor and Kahles, and they're all true 1x and are very easy/fast to use.
4) price. ACOGs are still somewhere around the $1k range. The older, heavier non 'E' version of the Razor 1-6x can be found for under $1k, and even the 'E' versions could be found on sale for $999 every so often, so price seems a wash (though you'd still need a mount for the LPVO).