Ok -thanks - that makes sense that the high velocity could/would be hard on the gun.
I did find the specs on the SAAMI web site. It shows both have the same 24,000 psi limit.
I can see where an increased slide velocity could cause a cracked frame on a HS, but, I've still seen people caution to not use HV ammo in old single shot rifles, like the Quackenbush and/or the Stevens.
I'm a bit unclear on how the higher velocity of the HV could do anything there?