Re: Understanding scope adjustments
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ballisticsman49</div><div class="ubbcode-body">I have a 5R milspec in 308 with a 6.5-20x50 vx3 and im thinking of getting a 20moa base. I am just having some trouble understanding the adjustment. For example the leupold has 94moa of vertical adjustment, so when the rifle is boresighted will the scope be around its middle setting and does this mean therefore that I will have approx 45moa of adjustment both up and down plus whatever the 20 moa base gives you?
My ballistics calculator say my 308 load will require 46moa of adjustment to get to 1000 so basically I want to know if this scope with a 20moa base will be enough to zero at that range or beyond.
Thankyou </div></div>
ballisticsman49,
After reading your post, it's hard to know if your confused, or you just used the wrong words.
First, a 20 MOA base does not add anything. So if your scope starts with 94 MOA of adjustment, adding a 20 MOA base does not give you 114 MOA. Rather it works more like this:
94 MOA is split 47 MOA up and 47 MOA down. Add a 20 MOA base, you now theoretically should have 67 MOA up and 27 MOA down. The 20 MOA base just "borrows" 20 MOA from the down adjustment. Your scope with the 20 MOA base "still" has only 94 MOA available, it's just distributed differently.
Next if your 308 load does indeed require 46 MOA of adjustment to reach 1000 yds, then it is doing so subsonically. So while your bullet may reach the 1000 yd target, your accuracy might well be very poor or non-existant.
Better to choose a load that moving faster than 1116 FPS @ 1000 yds. or at your impact point if your shooting further.
Just some things to consider.
Bob
