The only difference as I understand it is the sr cups are made of slightly harder alloy designed to take higher pressure without the risk of rupture. Never use sp in rifles but sr fine in pistol cases was what I was taught.
The only difference as I understand it is the sr cups are made of slightly harder alloy designed to take higher pressure without the risk of rupture. Never use sp in rifles but sr fine in pistol cases was what I was taught.
Bookmarks