Thanks everyone for your replies.
They have been very informative.
Sorry I wasn't able to join the conversation, as long work hours and home maintainance have consumed the past 2 days.

Nevertheless, my smallest group was with 150 gr Win Power-Points, and I don't even know for sure where I got them.
I plan to look through reciepts in an effort to aquire more of that lot#.

Thanks again for all your replies.