atse,
Have seen 140-grain 6.5 Bergers instantly kill prairie dogs at 500-800 yards--though the entrance hole was still a pin-hole, the exit wasn't. This was from a 6.5-06 at 3000 fps.
Have also seen "conventional" hollow-point boattails such as 85-grain Sierra GameKings fail to expand on PDs at 400-500 yards when started from a .243 Winchester at 3200+ fps. It didn't happen every time, but often enough.
Based on such experience, my bet is on the front end of Bergers collapsing over the "hollow point" of more conventional bullets mushrooming.
This is correct. The “hp” on an otm (ie berger) is there only as a result of forming the bullet. They are often pinched closed There is no means to initiate expansion on this type of bullet (ie a wide hp or soft lead nose). They penetrate a short distance in the much denser tissue and start yawing. The yaw increases surface area and keeps increasing and feeding back on itself. What generally happens is the tip will bend and cause the bullet to rupture or tumble if jacket is too strong. The more stable a bullet is before entering tissue the further it may penetrate before coming apart though it is still generally few extra inches (ie not feet). This type of behaviour is different than we are used to with hunting bullets that are designed to expand but very well documented and understood in wound ballistics literature as military bullets behave this way
This is why bergers penetrate a few inches then fragment. A thicker jacket may not fragment as easily though as
Bullet tumbles over it will still do damage. An increase in area does not matter if it comes from an wider front or side profile of bullet though one will generally penetrate more straight than other:)
Lou
