It has become clear that the scope base on the Reidl is causing the "not hitting where you aim" issues. First the Lyman ran out of both elevation and windage while still printing approximately 6" high and 6" right. Next, the Simmons ran out of windage "on", but also ran out of elevation while still printing 4.5" high at 35 yd. The rings are Burris, and I assume that the base is too. Regardless, something has to be 'done' about the base.

I removed the scope and the base.

The barrel is 1.139" in diameter at the rear hole, 1.125" at the middle hole, and 0.865" at the front hole.

The hole spacing is:

3.30" from the rearmost hole to the front hole.

0.80" from the rearmost hole to the middle hole.

Which means 2.50" from the middle hole to the front hole.

I have radius guage set, and the radius of the front of the base is .4375" (7/16ths). Unfortunately, the set only goes to .5000" radius (1 inch diameter), so I couldn't get an exact measurement on the radius of the rear of the base. I will assume it is 1.139"/2 or 0.5695" because the rear of the base fits the barrel pretty well. What that means is that I would need to get a mill cutter of diameter 1.139-ish if I wanted to mill the rear of the base 'shallower'. I probably do. Here's why:

The thickness of the base behind the rear screw hole is 0.232".

The thickness of the base at the front of the middle screw hole 0.205". That means a taper of approximately .027" per inch. The change in diameter of the barrel over that same inch is 1.139 - 1.125 = 0.014". So the barrel is getting smaller between the rearmost screw and the middle screw AND the base is 'thinning' as well. Combined that "tilts" the base down-in-front by about 0.041" inches. That's a lot! If I remember correctly, moving a sight 0.001 inches at the gun moves bullet impact by 1 inch at the target. (Don't quote me on that though, I'm not 100% sure I'm remembering those numbers correctly.) If I have those relationships correct, that's 41" of "up" at the target that the base is "adding".

The front of the base is uniformly 0.333" thick. The barrel is 0.865" in diameter at the front screw. Therefore, adding the thickness of the base to the HALF the diameter of the barrel we get 0.333 + 0.4325 = 0.7655" for the height of the top of the base above the centerline of the bore.

The rear of the base is 0.232" thick. The barrel is 1.139" in diameter. Half the diameter is 0.5695". Therefore the height of the rear of the base above the midline of the bore is 0.232 + 0.5695 = 0.8015".

Now, if the height of the rear is 0.8015 and the height of the front is 0.7655, then there is 0.8015 - 0.7655 = 0.036" of "down-slope" to the base. That is 36" of "up" at the target.

So, using only the measurements of the base I get 41" of elevation ADDED by the base, and using both the taper of the base and the taper of the barrel I get 36" of elevation ADDED by the base. Either way, that's too much tilt in the base. I think I need to take 0.036-ish off of the rear of the base.

Paul