Berger bullets do not "open" as many have stated here. They tumble end over end due to the lack of shoulder stabilization when they enter terminal media. When they begin this tumble, the nose will shear off and you get the dramatic berger effect. It is how they are able to combine explosive performance and very adequate penetration (which is caused by the long neck, or upset length before this tumble happens). However, this type of expansion can be more erratic than a tipped or exposed lead bullet, because there is no mechanism to initiate expansion on bergers. This is why you hear so much YMMV with them, some people love them and some people hate them.
Berger hunting jackets are actually thinner than their target jackets to promote them opening up, since they don't have tip-initiated expansion. This is in contrast to something like a Hornady eldx that will have a thicker jacket than eldm. Hornady knows it's going to expand because of the tip, so they try and control that with jacket thickness. Berger knows it will penetrate because it doesn't open right away, so they try and facilitate expansion with a thinner jacket.
Using any bullet, its good to know their performance envelope and what will make them fail (because all bullets will) and choose the right bullet for your hunting style/terminal requirements. For HPBT (berger included), this is generally delayed or lack of expansion due to the bullet taking longer to tumble. This is generally observed at lower velocities below 1800fps. Knowing this, you can alter shot placement a little bit and favor some shoulder with diminished velocity to help out here.
Berger hunting jackets are actually thinner than their target jackets to promote them opening up, since they don't have tip-initiated expansion. This is in contrast to something like a Hornady eldx that will have a thicker jacket than eldm. Hornady knows it's going to expand because of the tip, so they try and control that with jacket thickness. Berger knows it will penetrate because it doesn't open right away, so they try and facilitate expansion with a thinner jacket.
Using any bullet, its good to know their performance envelope and what will make them fail (because all bullets will) and choose the right bullet for your hunting style/terminal requirements. For HPBT (berger included), this is generally delayed or lack of expansion due to the bullet taking longer to tumble. This is generally observed at lower velocities below 1800fps. Knowing this, you can alter shot placement a little bit and favor some shoulder with diminished velocity to help out here.
