Hi
I found that my Long Lee shot very low with MkVII ammunition and it had me stumped for a while at the range. To get the shots consistently on the paper at 100m range, I had to have the rifle sights set for about 400 yards on the scale.
I have a BSA No.9 aperture sight that I bought on the auction site you mention, but haven't fitted it yet. I too thought that once set up, this would be the easy way to compensate for the different ammunition.
More info can be found here:
http://www.rifleman.org.uk/BSA_sight...sories.htm#No9
Kind regards
Mike