Mr. Brown, how is your study going with the R model 16 you confessed to buying this summer? Did you give up yet?
Best,
Ted 
Well, I did give it to JJ to see if he can figure out what's going on.  I'd shot 2 or 3 rounds of skeet with it when it started to double on me.  Thought it might have been the Herter's loads.  Switched to RST 3/4 oz, still doubled.  And it's certainly not due to light trigger pulls.  In fact, I asked JJ to lighten them up a bit--they're currently at 5+ and 7+ on a sub-6# gun--once he's determined why it's doubling.  He said that's very unusual for a Darne.  Leave it to me to find the unusual one--when it's one that fits, is in nice shape, and might have convinced me that I can live with a Darne.