Bob,
I'd happy to comment on those guns. My first BSS boxlock was a 12. ga. 28" barreled sporter that weighed 7 lbs. 6 oz. and I shot it well at clays and game. I came across a BSS sidelock 12 ga. with 26" barrels that weighed 6 lbs. 8 oz. that handled great and had to have it. It has become my go to bird gun shooting RST 2 1/2" papers with #8-7-5 shot at 1175 fps. I came across a 20 ga. BSS sidelock with 26" barrels weighing 6 lbs. 3 oz. in mint condition and it followed me home.
I love my 28-20-12 ga. Merkels, but those BSS sidelocks are special to me. I regret letting go my BSS sporter that got me started. Doublenut had a 20 ga. BSS sporter with 26" barrels at 6 1/2 lbs. for sale here that still haunts me.
Karl