I've met many folks who insist on buying 174 grain Sierra Match Kings and other boat tail bullets to shoot in their well used Lees and the results are usually disappointing. Folks shooting the new ROF(F) Mk.2's and other rifles in exceptional condition are having good success with them. I always tell them to switch to 180 grain Sierra Pro Hunters or comparable flat base bullets from other manufacturers and there's always noticeable improvement in accuracy from average, well used rifles. Remember that the Mk.7 was the specified rifle ammunition and the Mk.8 designed for use in machine guns. I'm guessing the boat tails were preferred for long range fire from the Vickers MMG. A story about their use in Korea comes to mind not to mention all of the Mk.8 I've ever acquired over the years was cased and on Vickers belts.