Jason,
Course of fire for the Palma Match is 15 shot strings at 800, 900 and 1,000 yards, for a total score of 450 possible. As others have stated already, the match calls fro a gun chambered in 7.62x51/308 Winchester and iron sights. All shooting is done prone, slow fire.
It's important to understand that the 155 grain bullets that we use in this game are there because of the rules; not because they're superior to heavier, higher BC desgins. Believe me, we'd use them instead if we could. Ditto the 308 chambering. Again, it's because of the rules, not because it's an optimum 1000 yard round. A couple years back I was squadded next to a girl shooting a 6.5x284 at Perry. Back at the 1000, she was consistently using exactly half the windage I was on my Palma gun with the 155s. Half. If I had ten MOA wind on my gun, she needed five. Five on mine, two anf a half on hers, etc.. It's also important to understand that these aren't run of the mill 308s, either. Most shooters use a stiff charge of Varget (probably the #1 powder choice for this community) and the shortest barrels you'll find are 28" or 29" long. You need a minimum of about 2950 fps out of these bullets to keep them supersonic at a 1000, something you won't be able to reach with a typical 24" barreled gun. Yes, it's a specialized game but it's a lot of fun.
Anyway, if you're just looking for something that'll do 1000 yards out of an existing general purpose type rifle, go to the heavier, higher BC type bullets. The 155 won't do for you what it will for a shooter using a true Palma rifle.