Re: reloading work up for long range
In a nutshell, buy a chronograph and learn how to "read into it" for uniform velocities. Don't get too concerned with 100 yard accuracy as much as getting a good consistent standard deviation. Then check that load at 100,200,300,400, clear out to 1000 if that is your intended range of fire. If the load shoots decent but not as good as you want at 100, don't give up on it if it has a low standard deviation. It may just put them in the same hole at 300.
Now there are a million other tips and techniques to get that magical load with a low standard deviation, but there is not enough time tonight to type them all out here so keep posting questions here and read as much as you can and you will learn them all if you get serious enough to retain them.
If it's not far, it's boring.