I have a Remington Classic in 6.5x55 and three old Swedish M96 mausers. I use Lapua brass in all of them. You don't have to deburr the flash hole because the primer holes are drilled, not punched so there's no projection protruding inside the primer pocket. You might have a slight problem with your shell holders. There's a bit of variation in the head size betwen U.S. and European cases. Other measurements may vary slightly, but not enough to affect chambering. Once the cases are fire formed by shooting you're okay, except for the shellholder issue. Forster makes a MU4 shellholder that's perfect for the job. For what it's worth my most accurate groups have been fired using Lapua and VihtaVouri compomnents. It's one sweet caliber. Best wishes.

Cal - Montreal

Lapua -- bar none. The consistency is simply amazing, the flash holes are drilled, not punched (and not off-center!), the cases are properly annealed, and the price is reasonable for the quality. The last batch I purchased ran app. $35 per hundred. Yes, WW and Rem brass is cheaper, but if you are a stickler for performance, you'll find yourself culling 18-20 pieces of Remchester 6.5x55 brass per hundred pieces, which makes that "bargain" brass not such a bargain after all. I have yet to cull a single Lapua 6.5x55 case.