The point of this thread is to remind myself and others that the devil can be in the details. It can be very frustrating when you can't hit a target at "long range" particularly if you don't know why. There are so many variables and when things don't go right we can start questioning everything and that can erode confidence in the equipment and oneself. My apologies if my thoughts in this thread aren't organized but it's late ... so here we go! I bought a Tikka T3 TAC NS back in July from a friend and have been impressed from the get go. https://www.thehighroad.org/index.php?threads/new-used-rifle-tikka-tac-ns-300-win-mag.871202/ I'm planning on using it for deer and elk this fall and have had very good results shooting 180gr Federal Premium Vital-Shok Trophy Copper (.300 Win Mag). This afternoon I wanted to check the Applied Ballistics dope out to 700 yards and the app on my phone was spot on with corrections of 0.3 milrad at 200 yards, and 1.6 milrad at 400 yards. The app called for 4.0 milrad at 700 yards (assuming a 0 degree angle to the target) with 0.1 milrad of spin drift to the right. That particular target is probably 10 to 15 degrees up angle so I figured on 3.8 mils of correction for elevation. So here we go ... holding off the left edge of the plate but centered for elevation ... MISS .... MISS .... MISS! I couldn't see where I was missing with the first three shots but on the fourth shot I saw splash just to the outside of the bottom right corner of the plate. Once I knew where I was missing I was able to dial up another 0.3 milrad, hold off a little more for wind and then DING, DING, DING ... I could hit the plate at will but hits were to the right of center, at least a 1/4 plate right and more like 1/3. Hmmm ... it didn't seem that windy. I have a few of the HORUS ASLI units on some scopes including the NF on this Tikka. I thought I'd leveled everything up a few months ago, but when I leveled the top of the 100 yard target backer board and aligned the reticle to the board I noticed that the HORUS bubble was way off. When I install a scope I use feeler gauges to get it level to the receiver/rail, then use a bubble level to get the HORUS level with the reticle. I'm not going to do that anymore, not the last part anyway. This afternoon I assumed that the scope was true to the rail (based on feeler gauges), aligned the scope reticle to the 100 yard board and then readjusted the HORUS so that the bubble was in the correct position. So now back to the 700 yard plate. The next 5 or so shots all landed in the center of the 12" plate holding 0.5 milrad off the left edge (8 to 10 mph wind) but centered for elevation. Finally I went back into the Applied Ballistics app and edited the ammunition data by guessing G1 BCs for different velocity ranges until the data appeared to match my results out to 700 yards at least. The problem with G1 BCs is that they don't account for velocity. I have a high level of confidence in the MV that I measured using a LabRadar system so the only option is to adjust the BC over a few velocity ranges. I need to do that for other G1 based ammunition profiles that I set up in AB. If someone would check my math and let me know if I'm thinking about this correctly. If I'm dialing up 4.2 milrad for the 700 yard target, and have a 5 degree clockwise error in terms of reticle/scope rotation from level, I'm inadvertently dialing in 0.37 milrad to the right which at 700 yards is 9.2" to the right. Even at 2.5 degrees of error, I'm dialing in 4.6" of horizontal error. Does this make sense? There are many variables to control in order to make first round hits on small targets at longer ranges, but having a level scope is one of the variables that we shouldn't have to worry about. In the bottom photo, it takes a tiny rotation to get the bubble to peg to one side or the other so as long as the bubble is off either extreme I feel that the scope is more than level enough.