The Vortex and Nikon scopes I've been purchasing in recent years all have the BDC hashmarks that are supposed to allow you to sight in at 100 yds and use the hash marks for longer distances, but I was wondering how they actually compare to what I shoot. I did a lot of searching on the net and watched a lot of videos before I found what I was looking for.
Here is the information from Vortex: The first hash mark is (at max power) 1.5 MOA, the second at 4.5, third at 7.5 and the crosshairs thicken at 11 MOA. They caution that an MOA is really 1.047".
They say for "Class A" cartridges (includes 30-06, 308, 270, 6.5 Creedmoor) to sight in at 100 yards, for 223 sight in at 200 yds (the first hash would = 300 yds), and 22 lr at 50 yds (hash is for 70, 90, 110, 130).
Being a reloader, I'm shaking my head! The difference between a 150 grain and 180 grain in an 06 (or 130 vs 150 in a 270) are substantial, as is the BC of the bullet.
I calculated the scope drop from the Vortex information (based on a 100 yd sight in) as follows: 200 = 3.1"; 300 = 14.1"; 400 = 31.4" and 500 = 57.6".
Most spitzer bullets pushed at about 2,800 FPS will give you drops close to these #s.
My 338-06 has a MV of 2,700, but the 210 grain Barnes TTSX has a high BC (.482) which helps to make up the difference at longer range.
My actual drops for a 100 yd sight in are: 200 = 4.0", 300= 14.8"; 400 = 33.3" and 500 = 60.6".
Good to know this information. The farm has 400 and 500 yard shots. The scope settings are close enough for out to 300 yds, after that I should hold just a bit high.
If I were to increase velocity by 50 FPS, I would be pretty much right on the money! However, my load is accurate, so I'm keeping it.