Dead-on at any distance with trajectory-matched dials that make hold-over obsolete.
Burris Optics of Greeley, Colorado, has distinguished itself with new branding and a flood tide of new riflescopes. Several of my rifles wear Burris scopes, among them are a couple of 6x fixed-powers (now discontinued), plus the recent Veracity 2-10×42 and Fullfield E1 2-7x35—practical, affordable variables with fine optics.
This spring I unboxed a Burris AR 4.5-14×42, a scope with a replaceable elevation dial scribed in yardage marks to match the arc of a 5.56mm bullet (it can be ordered with a dial matched to the arc of the 7.62 NATO as well). After zeroing, you use the supplied Allen wrench to loosen the dial, then index it to zero at 100 yards and snug it back up. Rotate it to the 200-yard mark to hit with dead-on precision at that range. Ditto for 300, 400 and 500 yards. You get to 600 yards before full rotation—far enough for most target games, and farther than responsible for shots on game. The Burris dial does not have a stop to prevent full-rotation error. That is, if in a fit of exuberance you spin it a full turn beyond where you should, you’ll get no indication from your dial that your bullet is heading to the moon.
Now, 5.56 NATO and .223 Rem. ammunition comprises a broad range of bullet weights and types. Trajectories vary along with starting velocities and ballistic coefficients. Burris has configured its AR elevation dial to match a 55-grain NATO load at 3,200 f.p.s. Other loads (or this load from barrels of different lengths) will change point of impact slightly, relative to the dial.