????
Perhaps the subs are bad, or your barrels simply don't like them!!!!
I've had several subs that look like a shotgun pattern, but at the same time, so do many of the HV, PERSONALLY, I have never found a HV .22LR to shoot as tight as a sub! (this could be the start of a whole new topic, Do you have a HV .22lr with better groups than your favourite Sub???)
I am getting 100yard groups as tight in my HMR as the OP is at 25 yards with a HV .22LR (and nearly as tight with the WMR at 100 yards). Hence why, for me, if I need the extra clout of a HV .22LR over a sub I will always re