some adjustments on the BSA "midway mildot":
http://www.snipershide.com/[email protected]
yeah it's not top shelf, and for any really serious shooting would go with just about anything else, but so far no issues.
being SFP, perhaps using X number of dots @ ___X magnification will get you out there as a holdover, or using the same for zeroing, using a dot or two for holdunder. just keep good notes of where you are starting, ending, and returning to.
but previous experience with higher mag scopes and short range deer hunting, you sometimes "lose" the deer in the optic or just see "brown" as the lowest setting is 6X.
i have the weaver tactical rings on mine too, i actually see no "real" difference between their tactical rings vs their regular rings other than there's more girth to them and some extra screws. the size of the cross / mounting bolt is no different than the typical cheapie weaver walmart rings and are not a solid mount on their, or anyones picatinny slot sized bases. though i've had no real issue with them once mounted, they are for me just a bit of a letdown.
http://www.snipershide.com/shooting...-20-moa-base-weaver-tactical-rings-level.html
perhaps consider burris rings, with the moa inserts could help you out gaining more adjustment, if you need it.
if it's a budget build, you usually have to be prepared to give up some stuff. but if you can get better quality (straighter, stronger, truer, etc) stuff, it usually produces the best results and worth the wait to put it together. for 400-500 yards you can usually get away with cheapie stuff, going out to longer distances, those little things add up quick.
for the base i'd go with something of a better quality material and better tolerances for "serious" shooting, no matter what the rings or optic is or going to be, they start at the base.