My rifle mentioned in the linked thread is a 1/12 twist, so it's a light bullet rifle. In fact, the heaviest bullet I've put through it is 52grain HP canned heat from Georgia Arms.
I've shot (off the top of my head):
UltraMax 40 and 50gr ballistic tip
Hornaday 40gr Vmax
Black Hill Red and Blue 40 and 50gr Ballistic tip
Winchester 40gr silvertip
Georgia Arms 52gr HP canned heat
Wally World Winchester value pack 45gr varmint stuff
Remmington something another (it sucked)
Everything shot under an inch at 100yrds EXCEPT the Remmington.. it was horrible. It was also a pretty old batch that my friend had laying around.
The Ultramax, hornaday, and blackhill red/blue ALL shot well under an inch, with quite a few .5-.75 5 shot groups. The ultramax is the best bang for the buck, but it's velocity is the slowest by several hundred feet per second.
The hornaday did pretty well, but it's just damn expensive. I'll probably be shooting the BH blue box with 40gr bullets.
I broke it in by doing 5 shots, clean, 5 shots, clean etc.. for a couple dozen shots, then cleaned about every ten shots or so. I was also trying to check some different ammo brands, so I cleaned it probably more than I "should".
All in all, I am *VERY* pleased with my rifle. It shoots almost anything well and several loads exceptionally well.