ORIGINAL: Vapodog
It makes no difference as any groups reported to the internet are 1/2".....always!!!!
Ideally we measure the two most distant holes center to center using (hopefully) a dial caliper.......but it really don't matter as no matter what it measures...it's 1/2"...unless you're shooting 200 yards and then it's 3/4"
Vapodog,
You need to get a new gun if all you can get is .5. There aint a deer in the world that's gonna die unless you can shoot .25
