There's always disagreement when in some form or fashion, a 6ppc is not hailed as the greatest and best in all things accuracy. It's been my experience that the 6ppc and typical powders used in it make it harder to tune than a 6br with its typical powders. Granted, there is a wealth of knowledge and an entire industry built around this case. But for a beginner, I don't see enough difference in accuracy potential to say that the ppc is an absolute in terms of being better. The best shooters are also the best at knowing what to do, and when, to keep a ppc in tune all day. Tuners help this a lot, regardless of caliber.
My advice would be to go with a 6br or 30br and a tuner. In the 6br, start with H322 and/or n135 for light bullets and rock on. For the 30br, the satndard is h4198, but there are others that have proven to shoot well, too.
Then comes the PPC. While there are other choices seen on occasion, N133 is by far the most used powder with light bullets, which is pretty much all you see shot in a ppc....n133 with 60-68gr bullets in 13.5-14 twist barrels.
This combination is fantastic when in tune. It's been my experience that when it goes out of tune, it can often do so in a hurry..hero to zero...and not the good kind of zero. There are people that are very good at keeping one shooting all day, but there are also people that have been shooting them for many years and still struggle with tune issues. In fact, it's been said by some well respected shooters in the game,that there is likely a pretty small percentage of them that are truly tuned well at most any match.
I got away from the ppc for this reasxon. This was before widespread tuner usage, so I may migrate back toward them in time. But, while most of my shooting over the last several years has been with some variation of a 30, I have had good luck with a 6br, and a 220 Beggs, aw well. I have never seen them as being difficult to tune and maintain reasonably well, that tune, throughout the course of a match. Nothing is impervious to tune changes as conditions change, but the 6br IME does seem much easier, particularly if you plan to go pre-loaded. Either way, weight limits are generous in UBR and I'd seriously consider using tuner on whatever you shoot. In fact, i'll likely never shoot competitively without one, again.--Mike Ezell