OK, maybe I made a mistake.
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I have experimented with 454 H110 over loads and 45 Colt H110 reduced loads:
1) 20 gr H110 250 gr XTP 45 Colt brass large pistol primer, 1.6" OAL, strong roll crimp, shoots ok
2) 21 gr H110 250 gr XTP 45 Colt brass large pistol primer, 1.6" OAL, no crimp, primer goes off but powder does not burn.\
3) 40 gr H110 405 gr cast, CCI 200 large rifle primer, 2.75" OAL, cratered primer
4) 40 gr H110 405 gr cast, CCI 200 large rifle primer, 2.1" OAL, cratered and top hat primer, .004" ~ .005" case head expansion, case starting to crack, recoil broke the Walnut wrist of the 410 shotgun firing this round.
What does it all mean?
1) The idea that H110 loads cannot be reduced is an over simplification, as seen with the 56% charge that works.
2) The small rifle primer pocket in the 454 Casull case head design was not needed for functionality, as seen with 200% load that works with the large primer pocket.