The last time I messed around with bolt-actions, I just slapped on the recommended Seekins 20 MOA base w/o giving much thought as to 'why'. I have a vague understanding that using that base would allow me more 'room' for elevation adjustments in the scope I was using (a Bushnell Elite 10x IIRC), correct?

This time I'm planning on using a Vortex Viper HS-T. I'm not really wanting to use a base, but I'm wondering if it's necessary? Like I said, I have pretty limited knowledge when it comes to long-range or precision shooting.

I don't suppose there is a Dummies Guide to.... book on this is there?

If one is shooting at long ranges without the benefit of an exceptionally flat bullet trajectory, it’s possible to “run out” of elevation in the scopesight. For example, if it’s necessary to have 60 MOA of elevation to hit a 1000 yard target (I’m just making up these figures), but the sight permits only 50 MOA of elevation, then it won’t be possible to adjust the scope for a center hold on the target.

If, however, the scope base is tilted and adds 20 MOA of elevation to what the scope permits, then the shooter has a total of 70 MOA to work with and would be able to use that scope for the purpose.

In addition to actually running out of elevation in the sight, there are disadvantages to having to dial up to the near maximum elevation that the scope permits. A + elevation base will help eliminate those disadvantages even if it’s not required for the max distance one is shooting at.

Whether an elevated base is absolutely necessary depends on the design of the scope and the trajectory of the bullet at the maximum distance one intends to shoot.

Added: One of the scopes of that model you mention has 65 MOA elevation adjustment, the other has 75 MOA. Keep in mind that specs like that usually require dividing the number in half to determine how much the point of impact can be raised above the centerline of the sight; the total includes the “down” adjustment. If that’s how the Vortex adjustment is specified, then raising the POI would be 32.5 or 37.5 MOA.

Cool, sort of what I thought. So a base is good to have, even if not required.

quote:

Originally posted by AllenInWV:
So a base is good to have, even if not required.

In my opinion, yes—although such a base does add a little weight, some height, and some expense to the mount.

There are, however, mounts that add the elevation without a separate base. They are pricy, but Spuhr mounts are available with 6 milliradians (~21 MOA) of elevation that aren’t taller or more expensive than their mounts without the added elevation.

A little height is no biggy. Heck, I figure it makes it easier on my. Base + low rings should allow a 50mm objective to fit with a 1/4" to spare.