Ruger "corrected" that some 1771s and 1773 7rnd GP100s could not fit 7rnds in without rims hitting each other.
What the fix was or if it went into production? no one knows.
I liked GP100s when they were max $600 for the stainless 4" (most desired). They were that cost from the time I was buying 2010-2018. Now, the GP100 ss 4" 6rd goes for 850, which is more than the 686. That makes no sense.
I have 6 686s and have had maybe 4 GP100s so far? I'm probably done with the GP100 line. For me, the GP100 double action is extremely weird with a two stage feel that I absolutely do not like. To each to their own, but someone saying it doesn't exist is bonkers.
While many claim the GP100 has a large ability for grips, only two types exist; ugly pirate peg and the shape it comes with. On the 686 round butt, any type of grip is available and from Altamont which makes the grips for the Delux. Eagle makes the current Python grips. Altamont has a similar.
I think the 686 has a much better trigger, even if you Wilson spring in the GP100 (which I did).
The GP100 "tank" talk is nonsense. The fact that the 686 has had the Plus 7rnd model for years and Ruger struggled/struggles with the GP100 7rnd cylinder lead me to realize the cylinder window is larger in the 686. So the guns are the same size basically, but the cylinder window is larger on the 686.
Never read of a top strap break on either 686 or GP100. Dollar for doughnut, the top strap is not the "strength" of a revolver. I don't buy anything into the GP100 being stronger. 357 Ruger loads do not exist either. The third lock up on the GP100 extractor is great. It's not needed and it's not mechanically all that amazing.
So smaller feeling, yet bigger, not cast, better trigger factor and 160 shipped back to S&W you get a trigger job, fully functional on 7rds...why not go 686? Then through in the crazy costs today that put the GP100 the same or higher than the 686? nope. Make no sense today.