When I return stateside again in March I will start making .416 hollowpoints (on par with a speer TNT) between 300-375grs (possibly lighter). When I purchased my 416 weatherby I knew I would never use it for what it was designed to do. Of course in Oregon we have several big nutrias, rockchucks and coyotes that demand a lot of killing power
I wanted a .416 Varmint bullet for these critters that would explode on impact. They might be what you are looking for. If you are looking for a 300gr deer bullet I may be able to bond and close up the nose a bit to make it far less explosive but if you hit bone I think your deer will be shot, skinned, gutted and deboned before it hits the ground. Again through until I am able to test them out I can not give you a definite answer. Barnes makes the X bullet in 300grs should be a awesome bullet for deer and antelope but there on the expensive side for plinking.