I was wondering if anyone knows the answer to this question: will there be an actual physical difference in a drop chart for a 20 MOA base vs. a 0 MOA base?
No.
I realize velocity, etc. would stay the same, but will the bullet from one of the bases impact higher than the other at a set range other than the zero? If both bases were zeroed @ the same range?
No. Example, if you zero two identical rifles at 200 yards, but one has a zero MOA base, and the other has a 40 MOA base, and then shoot at a 1000 yard target with both rifles, the bullet drop from both rifles will be identical.
Or does the 20 MOA only allow the scope zero to be set with less clicks for an extended range?
No, the adjustment from your zero range to the target at extended range will be the same regardless of the amount of taper on your scope base.
I'm just trying to see if buying a 20 MOA rail would be worth it for me, ballistically that is.
You need to evaluate a couple factors to see if a 20 MOA is a good fit for you. First, how much total elevation travel does your rifle optic posses? What is your minimum intended zero range? What is your maximum intended range for the rifle?
I think I over-thought this, and now I'm confusing myself lol... Will I be able to use my ballistics program accurately with a 20 MOA base?
Yes, all ballistic programs will function perfectly no matter the base you put on the rifle, provided the ballistic solution doesn't exceed the elevation/windage adjustment of the rifle.
Fire back your next set of questions..after you answer the ones above....make sure this get's cleared up!
The main purpose behind a canted base is to permit elevation adjustment of your optic at extended ranges. With a 0 MOA base, your optic is roughly aligned (should be depending on the profile of your receiver) with the bore centerline. If your optic has 50 MOA total of elevation travel, then with a 0 MOA base, the elevation adjustment is probably close to center with a 100 yard zero, leaving you 25 MOA adjustment up and down.
Long range hunters would rather use that 25 MOA worth of adjustment towards long range elevation travel...so they mount 5, 10, 15, 20 etc MOA bases to their rifles to extend the useful elevation range of their scope.
In the example above, and if the optic was centered with the bore centerline on a 0 MOA base.....if the 50 MOA optic was mounted on a 10 MOA base, the optic would have 35 MOA travel "up" (bullet path movement), and 15 MOA "down".
In the same example, if mounted on a 20 MOA base, it would now have 45 MOA travel "up", and 5 MOA "down". This might be considered marginal on the "down" adjustment remaining, to ensure the capability to zero at closer (100-200 yd) ranges.
Another factor to consider, especially with factory actions, is the profile of the action can contain significant alignment errors (both windage and elevation, but will focus on elevation for this post), that can "rob" your optic of some travel (sometimes as much as 5-7 MOA).
Additionally, some optics, have been known to "walk" or introduce a windage error at the extreme limits (top or bottom) of their elevation travel range...it's thought best to try a place the elevation adjustment towards the center of it's operating range, to minimize the chance/effect of this, no matter the quality of the optic.
Hope this helps! Good shooting!gun)
