To be honest, I was expecting that there was going to be minimal changes because:
- torch is mounted away from the barrel, so I didn't think that it wasn't going to affect the vibrations and hence accuracy;
- although extra weight, I didn't think the recoil of the 22 was enough to have it affected by this extra weight. I know that high power rifles shoot lower if they are heavier - very pronounced if the extra weight happens to be a bayonet.

I can't understand how the extra weight made the rifle shoot (marginally) higher in my case.

I have suspicions about the flyers - there were all low. I think maybe I was pulling the rifle down more onto the sandbags when the flyers occurred, and this may have ever-so-slightly bent the barrel upwards (it is a long skinny barrel). I tend to relax as I release the shot, so the barrel would have bent down to its neutral position when this occurred. The flyers were typically between 5 and 10mm low at 50yards so would've only required approximately 2 to 4thou" bending at the rifle - plausible?