I use Hornady dies and use very little crimp. I have loaded the .454 with no problems yet have shot over crimped factory loads that recoil pulled boolits.
Case tension is needed first, then just enough crimp. Crimp alone will not save you and making factory load crimps stronger can actually weaken case tension. I have seen full profile factory crimps let boolits move with 3 shots.
Mine never pulled up to 55,000 psi with the same weight boolits.
Make boolits heavier and not much will hold them. You can not over come inertia with brass or crimp.
This is my boolit from a home made mold, 440 gr for the .500 JRH at 1350 fps. It is the fifth round after firing four. Notice the mild crimp and the case tension. I also get this boolit to hold from the .500 S&W.
If you think you will hold a 700 gr boolit you are barking at the moon.
Factory cast loads have double my crimp, yet move out of brass.