I'm in agreement with the above comments. Momentum gets the job done, so heavier bullets at moderate velocity are the way to go. You want to balance the power with the need for speed and accuracy and a 215 gr bullet at 1200 fps might be a bit of a handful for either.
On the other hand, a full power .38 Special with a 158 gr flat point bullet however is as low as I'd go, and a .357 Mag is a much better choice.
A DA revolver in .45 Colt with a 255 bullet at around 800 fps is a good choice, as is a .44 Special with a 240 gr bullet at around 850 fps. A .357 Mag with a 158 gr bullet at 1300 fps will produce exactly the same level of momentum as the .44 and .45 loads above, which is 29 compared to 36 for the OP's 215 gr load.
In comparison, a .38 Special launching a 158 bullet at 850 fps provides a momentum of just 19 - a bit less than 2/3rds of what you get with the above loads, so shooters are handicapping themselves with a .38. However, if you shoot a .38 really well and cannot shoot a .357 Mag or one of the .44's or 45s nearly as well, the .38 Special might be a better choice for you.
For the semi-auto class I use 230 gr RNFP bullets at 900 fps in a .45 ACP, which also gives the same momentum (29) as the .45 colt, .44 Special and .357 mag loads above.
Bullets with flat points, wad cutters or semi wad cutters seem to be preferred and at least theoretically grab the pin a little better if you're a little off center on the shot.
For the rim fire class, the pins are normally set on the back edge of the table, but again momentum is what you want so stay with 40 grain bullets rather than lighter, faster rounds.
Despite it being a timed event accuracy is also at a premium. You can hit a pin fast, but if you hit it off center and all it does is spin on the table, you've just lost a lot of time compared to a slightly slower shot better placed. It's harder to hit a spinning pin center of mass, so that less than perfect first shot often ends up resulting in two more shots to get the pin off the table. Thus a miss in the revolver class often equates to a reload when you've got 5 pins and just 6 rounds. Even if you're really good with a speed loader, the time needed of the extra shots, plus the reload will normally put you in the losers bracket.
In the rimfire category it comes down to accuracy and reliability. A missed shot will often put you in the loser's bracket, and a miss feed is the kiss of death.
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I enjoy the bracket style matches much more than the timed events due to the fun of shooting head to head with another shooter. In addition, if you screw up really badly, and end up in the losers bracket, you can still win the match - something that doesn't happen in a timed match. That's more encouraging than flubbing your first table an then hoping other shooters make similar mistakes.
If you have a dozen or more competitors, and the match has both winners and losers brackets that pair the winners of each bracket at the end, no one ends up shooting less than 2 times and many shooters will shoot more than 3 times, and after the first table, anyone can still win the match.
Timed events usually involve shooting 3 tables for either an average or total time. The upside is everyone is guaranteed to shoot 3 times.
As noted above, there is an element of luck involved, and the pins start to respond differently, once they start to get soft (literally, from the wood fracturing inside the plastic skin). Soft pins are a bit harder to clear than fresh pins. That's another advantage of a head to head match, where at each stage you're shooting pins that are on average as beat up as the other guy's pins. That's not really the case if you're the guy shooting toward the end of the third timed stage in a timed match.
