Jsb mkI & MkII head size?

[Dts327]

I dont have a consistent way to measure head size at the moment so for those of you guys that do, how consistent are the jsb heavys for .25 im trying to get the last little bit out of my impact. Shooting 10 shot groups at 75y i always get 1 or 2 pellets that open up the group. Averaging 1-1.25" if i could get rid of the the 1-2 shots that open up the group it would be .75"-1" all day

 

[addertooth]

I use a pellet gauge. On the Mark II heavies, I get 6.37 to 6.38mm with extreme consistency, in the prime weight range. I haven't measured the head size on the pellets which are too heavy, or are anorexia light. They are culls to me. 

 

[Dts327]

I have been weighing and sort into 4 groups, 33.3 and under are for plinking. 33.4-33.8 and 33.9-34.4 are for groups. anything 34.5 and heavier for plinking