I am using a 9,3x64 for moose-hunting. For reloading amunition for practising I use LR primers only. For hunting I reduse loads so LRM primers may be used. It is two reasons for this:
1. The loads for hunting with heavier bullets is usually relatively heavy compressed.
2. In the latest part of the hunting season it might be as low temperatures as minus 20-25 degrees Celsius.
Due to this I feel a sequirity in using LRM primers, even if I have to reduse loads resulting in some lower velocity.
As everybody else I dont want to worry about the carteridge in the chambre when hunting.

But: Is it necessary to use LRM primers like Federal 215 in this carteridge with a case volum that is not really big??

I just use standard LR primers, ...........haven't had any problem down to -40 degrees during our winter!

~Arctic~

It depends on your powder choice. If you are using a ball type powder, you may want to go to a mag. primer in cold weather.