Lapua Vs. Lapua Palma Brass

Yes it has a small primer pocket so there is more brass in the head of the case supposedly making it stronger and less succeptible to loose primer pockets. You need to run a small rifle magnum primer if you use them.

I have never used magnum primers in the Palma brass.
 
Main reason for using magnum primers is they have a thicker cup and don't flatten as easy. If you use palma brass to run hotter loads, which is the reason for using it, might as well run a harder primer also. Wolf small rifle magnum primers are not any hotter that their regular primer but the cup is thicker.
 
My understanding, is for the small primer. That way they can use the small rifle primers like the benchrest shooters use. This was told to me (a benchrest shooter ) by another engineer (a Palma + benchrest shooter.) They are trying to get the smaller SD readings as well.