Thanks for all the comments and info.

I'm going to bench rest my LGM-2 at 25 yards indoors and shoot some groups with different pellets.

My 'gut feel' is that 20 yards indoors is doable with a 8J 10m rifle, anything over that distance needs 16J if shooting the NSRA targets.

Appreciate comments about lock time, benchrested I can feel the vibration of the hammer on the valve on the LGM-2 and the slight delay. Interestingly I don't feel this shooting 10m standing.