Omegalover
First of all welcome to the questions board - I believe this to be one of the best forums around combining great people and both areas of ML shooting - inline and traditional.
Just my personal thought - you are probably already shooting the best all around 50 cal bullet weight. The 250/260 grain bullet is really quite versitile offering many +++++. The 200 grain does offer more velocity, thus flatter - but on the other end - the business end I believe it to be a bit deficient - not much mind you, but enough to outweigh the velocity gain. If you are in need of constantly making a 200 yard shot on game (thin skinned game) then you should probably go for the 200 grain. If you are going after thick skinned critters then look at the 300 grain. I use it pretty much for both elk and whitetail and it functions great.
The twist of your rifle and matching the ultimate length & weight of the bullet you are shooting create stability - the greater the stability the greater the accuracy - excluding external forces.
I do not know that you NEED a chrono for your purposes but they are certainly helpful - that is the excuse I used to get one - I wanted to know velocity - now that I have one I only use it on occasions.
I am not shooting an Omega - I am shooting 2 Rems and an A&H besides a couple handfuls of side hammers. I am not sure this is the best load for my guns or not but it certainly is an effecient load on animals. I am not a fan of really expensive bullets or bullet sabot packages. Right now I am doing a heck of a lot experimenting with the new Speer Gold dots. They are a bonded bullet both 250 and 300 grain. I shoot them them and expect to perform from 20 yards to 150 yards. Conditions being right I would have know problem shooting 200 yards with them either.
All of this just my 2 cents....