I have used Barnes TSX bullets and like them.
I think the expansion situation might be related to the size of the meplat or hollow point. As the point or meplat increases in diameter the ballistic efficiency will decrease thus the VLD bullets with tiny openings or pointy meplats. Pointy bullets having plastic points always seem to expand, the pointy plastic tip above an empty area is driven into the empty area initiating expansion. Some VLD bullets might also have thicker jackets and during the bullet forming process work hardening might occur making the bullet more resistant to expansion. I have heard that some shooters anneal bullets. I have seen some VLD bullets that show surface lines that run parallel to bullet point, these might be stress fractures formed at right angles to compressive forces when the bullet was formed. Core hardness might also be an expansion factor, antimony is commonly added to lead to increase hardness.
A favorite bullet is the 6.5 107 grain Sierra MK. This is a pointy hollow point bullet and about 1/4 the length of the bullet at the front end is void (empty). These bullet zip right thru larger rodents like 8 pounds (rodent safaris) when driven from a 6.5-06. I have recovered some of these on top of soft dirt at extended ranges that were bent into L shapes. This bullet has a relatively thin jacket & soft core.
I won't use plastic tip bullets in my AR fearing that the little plastic tips might go adrift and jam things up.
All the above is from a shooter that has only shot a few deers but most of these have been big ones weighing over 250 pounds. I shoot rodents and am no safari type bullet expert. Rodent bullets of choice have plastic tips.
Bullet shown is a .257, 100 grain TSX from .25 Souper that went thru 3 feet of deer at 367 yards.
View attachment 443991
