I tested original Mk.7 just for fun last year using a 1" paster at 25 yards and a trusty Long Branch No.4 as a control rifle. As a testament to the quality control and standardization before all of the electronic age came into play, it ALL shot to the exact same point of impact with approximately the same size groups. This was BritishK '42, RG '44, Canadian
Dominion '42, Iraqi '61 and Pakistani '67. I had a few minor hang fires but the majority of it must have been stored well because it fired and was very consistent. The Iraqi had the smallest group!! They all were pretty much half minute at 25 yards.