Tom I would highly encourage you to not even listen to myself. Go out and spend sometime out at the range and you will soon figure what it takes minus any miss leading confusion or recommendations from someone else.

Tom, It hasn't been mentioned yet but have you slugged your barrel ? Knowing the exact bore size will help you decide which is the best size bullet you need.  Give it a try.  Dale.

40 Rod has given good advice. The main goal is to get to the least amount of vertical dispersion and then fine tune from there. The only difference between myself and 40 Rod was I would go up in 1/2 grain increments and then to 1/10 grain going both up and down. I would use five shot groups at a 100 and if I knew I pulled one I would add a sixth. I could very typically do this with a target or two very easily in one outing and I never cleaned or stopped from one group to the next. It was also quite typical once I got the vertical down to being it's least there would still be to much horizontal. A tenth or two in the powder charge would then bring the horizontal in making the groups nice and round and having no change to the vertical. I would not set out my chronograph until I found what I wanted as I did not what the velocity to influence what I was trying to accomplish and could careless what it might have been. When all was said and done I would then verify my average velocity and with my 32-40 it ended up being 1474. Now knowing that this was this particular bullets sweet spot I would simply go right to it when trying different powders, primers and seating depths. That approach has always worked out very well for myself and the quickest why to test several variations in a day. One I found what my rifle liked the very best my time was then spent on checking for day, day out and year round consistency. If I wasn't seeing it right away I wouldn't mess with it anymore and would simply move on with testing something else. The lack of consistency was due to the powder being used more times than it was not. The least of those that I have tested was 4227 with 300MP ending up being the best. But also keep in mind your rifle might just like the opposite of mine and why it is so important to try them all. This also holds true for primers, seating depths and just importantly testing in various temperature ranges as well from very hot to very cold. Temperatures can typically be delt with by small changes in ones powder charge and in tenths of which can change from one day to the very next. This holds true for my own personal rifle so I simply check the vertical on my sighter target to verify whether it needs to be slightly adjusted or not. It is also not untypical for me to shoot fifteen or more sighters to verify my charge needs to be where it's at long before going to a record target.