Quick question, is a 0-MOA base sufficient for 300WM at 1000 yards? I'm getting the IOR 2.5-10X42.

Not sure what the internals on the IOR are but you only need about 24-28 MOA in a 300WM to make 1000 depending on the load so a flat base would most likely work fine but why would you want to limit yourself with a round that can hit a mile? I'd suggest getting the 20 MOA to make sure you'll have plenty of MOA for extra long shooting. Will you do that type of shooting alot? Probably not but it's nice to have the MOA there if you need it. The 20 MOA bases doesn't cost that much more, if any, than the flat bases so why not get a 20 MOA.

The scope you mention has 88 MOA...

http://www.valdada.com/vn/ior/03h

Assuming your rail is pretty level with the bore, you'll be about centered in the erector travel of the scope, which means you'll have about 44 MOA of up/down.

Which means you should be fine.
Dan

44 MOA will get you to about 1300 yards assuming you don't have to use any windage to zero the scope which will take away some elevation travel. I'd still recommend the 20 MOA.

Use the 20 moa to keep any scope optically centered. At longer ranges when your cranking alot of moa in the scope (any scope) it's less stress on the errector tube.

flea

I agree with Flea.

Thanks again!