Re: 308 Win, 208 AMax, RL17
I took the 208 out to a mile and beyond today. (2620 fps via 50gr RL17, 20.5" 1/12 twist bbl).
Conditions were pretty nice. Clear, sunny, 75F light and variable winds generally from 10-11 oclock.
It took 90 moa to hit at 1771 yards. I was shooting at a juniper about 38" tall (.6mil, 36 x .6 x 1.77) , dark green, against a dry hillside of dry grass. I was shooting into the afternoon sun, so my splashes were very visible. I was about 500' or so higher than the target. I was firing prone from a shooting position I built in a small rocky outcropping on the front of a hillside. Lased distance was 1789 yards, calc'd to 1771 yards horizontal distance. Had to lase two segments and add them, so distance isn't precise, but should easily be within 20 yards or so.
I had very good consistency. My elevation calcs have been very close out to about 1200 yards, but at this distance, the calc was for 77.6 moa, but actual required was 90 moa (22 moa in erector, plus 20 mils on reticle). Not sure why, but possibly the bullet is flying a bit tip-up out there and losing it's BC some. I had dialed in 3.5 moa windage up front, to account for using the tip of the 20-mil reticle index mark for hold. The index extends 1 mil out from the vertical centerline. Only needed 2 moa additional right windage to get on target.
For shits and giggles, I shot a couple 155 Scenars, 2900 fps, at the same target. I didn't have data calcs that far out for the 155 Scenar, so I just used the data from the 208 (90 moa). Surprisingly the 155 Scenars impacted about .75 mil above aimpoint.
From there, I tried to engage a target at roughly 2100 yards with the 208. I was correcting 120 moa (19 moa on erector, plus 30 mils on reticle). Impacts were visible, but inconsistent.