I will touch on the record keeping again
For very close record keeping, I have a 3 ring binder for all my reloading info, I like to keep it 1 rifle to 1 book. I print off all my testing targets from the internet, 8 1/2 X 11 sheets, once shot they get 3-hole punched and inserted along with chrony data on that load. The chrony sheet has places for all data along with comments, powder used, charge used, bullet, OAL and temp on that day, you could add wind or other enviromental data, gets alittle deep though for me. There is no question if you tried something before.
The short version
Never throw away those old targets, take a sharpie and write the load data on the target along with a brief comments like pressure signs etc. Use a couple file folders to keep it straight. I have targets from testing going back years, come to think about it......I still have targets from rifles I no longer have /ubbthreads/images/graemlins/laugh.gif I should do something about that!!
Record keeping is just as important as anything else on your bench, it can keep you from wasting time, money, eyes, fingers or worse.
