Palma rifles don't have post front sights. They use adjustable front and rear apertures. You still generally focus on the front sight. All you do with the rear is center up the front in the rear and the target is blurry but centered in the front one. This is the same for really any distance from 50 feet up to 1000 yards. And yes, I have been involved in those competitions.

The hard part is having a solid hold and body control, reading the wind, and having super consistent ammunition that you intimately know all the elevation adjustments for. The remainder is how much money you spent on your barrel and how many rounds it has down it. A tight shooting coat helps a great deal, too.

I got bored with the whole thing when it occurred to me that I was just throwing money at barrels and other gear. Not to say that the game isn't highly competitive, but like auto racing, it's a money thing. Similar to many such pursuits, to take it to the max you will pretty much end up divorced.