I'll certainly agree with that last....sometimes you're ready to give up, then try a couple more loads, and VOILA! There it is! My Rem. 788 in 22-250 shot into about an inch and a half with factory loads, half that with my best loads. I toyed with powders and primers and bullets and seating depths and everything you can think of for a year, trying to find something better. On a desperate whim, I bought a can of IMR-4064, and the next session I about fell off my seat. Most groups hovered around the half-inch mark, a few around .400" at 100 yards. (That was the longest range we could shoot at.) I tried a Sierra 52 Gr. HP the next time out and shot five straight groups under a quarter-inch, the last coming in at .130 for five shots. I kept testing the load over the summer, and it rarely went over .220", unless the wind was blowing pretty hard. Even then, the groups were great, but a tad off to one side.
The next spring, right at the end of crow season, I blew one out of the top of a tall tree at somewhere between 400 and 450 yards, on the second shot, with three witnesses. My chest hurt for two days after, from sticking it out so far!
And then sometimes you just fall into a combination the gun likes with almost NO work. I decided to load some blasting ammo for my 30-30 last week, using scooped charges and an unproven bullet. When I shot them on paper this past Wednesday, I got four straight groups that were all nearly one-holers. Needless to say, I loaded up another 50 rounds right quick, the same way!
Sometimes you're the Louisville slugger, sometimes you're the ball!
Papajohn