With my revolvers, I am one of the screw balls who does trim his cases. I like to have my crimps as consistent as possible. That said, I don't weigh my bullets, nor to I tweak the charge to the last freckles worth. I set up my Uniflow to throw the charge weight I want and go for it.
I have found that the minor variances in powder weight usually do not matter with powders like 2400, 110, or 296. I am sure this also applies to other slower powders as well. What has mattered has been the depth of the bullet in the cases along with the crimp setting on them. I like to set mine up so that they are rolling the lip of the case right over the bottom edge of the cannalure. I also don't like to use too much, where it looks like the case is blended into the jacket, but it's simply firmly rolled into place, and you can see it still has a nice sharp edge on the rim.
Using this I have loaded for several calibers in which the handguns and loads are easily way more capable than I am, of putting them into small groups at long ranges. I usually use 50yds as my criteria for accuracy shooting offhand with my hunting revolvers. I feel if I can keep the shots under 3" there I am good enough for the ranges I shoot the most. This is usually pretty easily done, and with a good solid rest shots to 100yds aren't out of the question.
The following picture was a demonstration to my friend on the effects of over crimping his 41mag loads. He loaded the same loads in all of the rounds, however the ones on the left were crimped heavily and the ones on the right were crimped as mentioned above, backed off about 1/8 turn. Both were shot free hand at 40yds and the right group would have been better, but I wasn't accustomed to his wide sights.
I have found that with each revolver, like rifles, tolerances are different, and that in most cases the crimp along with case tension can and does influence the accuracy just as much as the powder charge or primers used will. When I work up a new load with a different bullet or powder I usually will seat them just to the cannalure, then take my small RCBS press to the range and start with a light crimp and gradually snug it down watching for the best groups. Once there, I will set up a dummy round and use that to set everything up later on. Might seem a bit more than most do, but then again I usually see better groups than what most post up, and at further distances. To me this says plenty, and I know I am not the worlds best shot, or a foremost authority in loading.
