When shooting elk out to 150 yards I can not see where trajectory really comes into play for an elk bullet. Maybe ground squirrels, but not elk.

Personally I like big heavy conicals for elk. Four or five inches above or below the line of sight is no big deal for elk.

Personally I do not pay any attention to twist rate for a conical. Yes the faster the twist the better it SHOULD BE. We all know that. But I have shot alot of conical in 1in66" twist round ball barrels with great hunting results. Maybe not target results, but definitely hunting accuracy.

Have you slugged your dad's barrel to see why the bullets are deforming?? Is it truly undersized??

I would slug that barrel. Then if it is undersized I would order some conicals that are properly sized, or just do it myself.

We have shot alot of the sabots and MZ saboted bullets over the years. And I have seen different results from the same bullet on different deer. We are talking about drastically different velocities with different MZ's and at different distances. So even the best bullets can have problems. And Yes that includes the Barnes and NP bullets.

I do know one thing for sure. A heavy conical will knock the snot out of an elk. Regardless of the velocity. Whether it be at 150 yards or 15 yards a 500 grain bullet is devastating. Even at 700 or 800 fps. So if you are accustom to conicals then I would figure out a way to make them work.

I can not argue with some of the guys with the accuracy they get from their sabots, and bullets. And I have used those myself over the years. But for hunting I have went back to the conicals. And I no longer have to worry about whether the bullet will or wil not do its job. If I can hit it, then say by by with a heavy conical. Tom.