[terry]

I took my american to the range yesterday and shot some really nice one hole groups at 50 yards. The problem is, I cant brag about the size to everyone because im not sure how to measure the group size. Outside to outside, center to center, or something else? Please help so I can tell everyone how this american will shoot. thanks.

 

[JimH]

Terry,measure outside to outside and subtract the bullet dia.Also even though the bullet may measure .222",the hole in the paper will be smaller and you need to measure from the black edge made by the bullet.

 

[3192]

Try this

http://riflestocks.tripod.com/calculate.html

I keep it simple by measuring outside to outside and then subtracting one bullet diameter from the total. This gives you pretty close to center to center with the only variable being whether or not your bullet holes are the same size as the bullet diameter that you used to subtract. Thus the prove it targets make you measure an actual hole and you only get to subtract the diameter of that hole not the actual bullet. Hope this helps.