So there seem to be two parallel discussions here: single triggers and strength of the 12/20 action. I do not have a strong the opinion on the ST issue although I would be somewhat reassured by the fact that these are relatively modern guns.
The 12/20 action is as strong or stronger than any conventional British SLE, indeed that is its beauty. Since it is a back action gun, the bar has no metal cut away for springs and is therefore solid metal. Furthermore, the action is cocked by a unique mechanism centered within the Purdey lugs that eliminates the need for cocking lugs to penetrate the bar, so again nothing but metal up front. All adding up to how a 12 bore can get by with a action body no wider than a conventional 20 bore. Hence its name: 12/20 or a 12 the width of a 20.
The issue is not action strength or resilience but rather recoil. Most of these guns weigh 6 lbs and a little change and therefore will really slap you if you shoot more than 1oz loads. I regularly shoot 7/8 oz comfortably but today shot a 100 clay round with 1oz loads at 1150fps without issue.
I believe I have seen the pair you are speaking of and they are beautiful guns. Truly London Bests…but light 27” 12 bores are not everyone’s cup of tea!
