I'm a little baffled on the subject, specifically in regards to the .284 BT hunting bullets. From the advice and experience of several here, I understand the 7mm 150 BT's to be pretty darn tough, but the 140's not so much. I also understand the 120 BT to be very tough.
The way I understand it is that the same jacket blank was used for the 120 and 140 BT.
Since the 140 must be stretched further, it ends up thinner than the 120.
The 150 got it's own jacket, because they acknowledged that they already were thinning out the jacket at the 140's, and couldn't take it even further to make the 150's.
At least that's the word on the street....
