Check the archives on the rifle silhouete board. Some good info there. Silhouette requires constant elevation clicking up and down for the four different ranges encountered in each match. Therefore, "repeatability" is absolutely necessary. If it doesn't come back to the same setting each time, and do it over a period of years, it's worthless. The old T-series Weavers with micro-trac are reputed to be among the best in this department but a question has been raised about the tracking of the new T-24 they just re-introduced. My older T-24 has perfect tracking after four years of heavy use.
Sightron is developing a good tracking reputation. So is the Bushnell silhouette scope. Lots of people use Leupold and I've been happy with the two on my highpower silhouette rifles but you do hear complaints about tracking problems from some silhouette shooters.
You want target turrets so you're not looking for a quarter between heats.
People argue endlessly about power. Variables are nice because they let you experiment with different powers or adjust the power to the range. I have enough trouble keeping up with sight settings already and just try to learn how to handle 24 power. Some of the best shooters are coming back down in power and reporting that 12 is plenty and makes the hold steadier.
By all means, try a few matches with what you have and do your research. The idea is to avoid having to do it twice. I have a BSA scope, now on my airgun, and I've helped buddies sight-in and test a couple of others. The tracking on these three scopes was unacceptable. I have a Tasco that is junk and an older "World Class" that has tracked just fine for 4000 rounds of highpower silhouette. The cheap scopes are a crapshoot. Expect to pay around $400 for a new scope with the features you need, perhaps a little less. If that sounds like too much, remember that it's about $150 cheaper than buying the cheap one first and then springing for what you need. Good luck and good shooting.
