Elk Load for 300 WSM

[Blkram]

The BT is a cup and core bullet designed for more rapid expansion, whereas the AB is a bonded bullet designed for better weight retention and better penetration.
The BT's have caliber specific coloured tips (.257 are blue, .264 are brown, .277 are yellow, .284 are red, .308 are green, etc.), whereas the AB's all have white tips. The tips aid in enhancing BC and in expansion, as the tip is driven back into the hollow point to initiate the expansion upon target impact.

The early BT's had some issues with too rapid expansion on lighter game, and was redesigned for better control of the expansion. Today, they are fairly robust and perform well even on larger game. But do not expect more than say 60% weight retention.
The AB's are rated for 70%+ weight retention. Although in every AB I have recovered to date, from .264 to .375 caliber, has proven to be in the 90-95% weight retention. And I have recovered AB's from game ranging from antelope to bison over the years.

 

[JD338]

You are correct Gil, Nosler redesigned the BT several years back and toughened them up. The 308 180 BT is indeed an elk bullet.

JD338

 

[IdahoCTD]

The early BT's had some issues with too rapid expansion on lighter game, and was redesigned for better control of the expansion. Today, they are fairly robust and perform well even on larger game. But do not expect more than say 60% weight retention.

Those early BT's were wicked on rockchucks though. We use to shoot the .30 150's about 3600fps out of various long belted magnums, 30-8mm, 30-358STA, 308 Baer, etc. If you want to see a rockchuck fly 30+ feet in the air that was the ticket. We tried everything from .22's to 416 RUM's and that combo was the best for "effect". Above the .30's the bullets were too tough and wouldn't explode.

The 180gr .30's and up were always built tougher. I cut a bunch apart and the jacket was over twice as thick in the base on the 180gr .30's, 180 and 200 .338's, 225 .35's, and 260 .375's. I had a buddy shoot a small whitetail doe with a 260gr .375 from a 375JRS (375-8mm rem mag) at about 50-60yds. Hair literally exploded off the deer. It was like a crime scene. There wasn't any hair where the deer landed but for 20ft in every direction there was a coating of hair everywhere. I wish we had smart phones back then to filmed it.