I went to the range today to get my muzzleloader on paper and can't seem to get enough adjustment out of my scope. Shoots low like 10 to 12 inches at 100yds pretty consistantly. I am using a Weaver 410 base, Thompson Center Maxima Standard rings, and a Leupold VXIII 3.5-10x40 scope. This is mounted on a Encore 26" barrel. What am I doing wrong / how do I fix this? The scope is adjusted as far as it will go. Thanks!