The rings were something I considered as a potential source of error. I used removeable rings. Steel Alloy quick release rings. Helps me clean the gun without cleaning the scope too, so to speak.

The rings however, I know are capable. I have the same set on my Mossberg 835 with ironically the same scope (only camo), and if they can handle the abuse that Godawful thing dishes, then this smoke pole is nothing at all.

I've been using an RCBS reloading scale to measure out my loads. I used the powder measure to approximate 90gr of powder, then dumped it on the scale. Did that three separate times and got an average of right around 58.5gr (thats smokeless grains). I figure no matter what, that RCBS is giong to be much more accurate than any other measure, up to and including pellets. But hell even that didn't help any.

The powder has sat in the closet, sealed save being used occasionally, for the last 14 years. Think that might have something to do with it? How often should I clean this thing while test grouping it?