The Model 21 is definitely NOT "another" boxlock. Its coil spring action is way more reliable than a V powered Anson action. Having had a number of V spring failures I can vouch for the superiority of coils over Vs.

Its round bolting is also interesting. I have talked to Italian makers who inists that a round bolt is destined to shoot loose, yet the Mod 21 does not. Neither do the Horsley guns and they too have round bolts. Engineering wise the round bolt is theoretically superior to the Purdey underbolt.

The puzzle for me is the slabsided action. It could have been made round, like a Westley Richards with no real effort. Guess it must have been the style of that time, or it was in tune with the slab sided mod 94.