OK, so I got a S&W 686-4 grail gun and ran straight to the range. Shot it several times but was somewhat disappointed. Then put a reflex red dot on it and shot it a bunch more. Still no love. I own several 686's and love them. Couldn't get the -4 to shoot a good group. It seems like two cylinders shoot accurately but the rest are low and wide left or right. My other 686's shoot 1 1/2" groups supported at 10 yards and this one shoots 6" groups. What's up?? Any Ideas?

That is weird. A 4" 686 was my first duty gun in 1985. I shot it thru my academy days and had one for years. We all loved them as officers and they shot great. So it's mystery to me. It sounds like the bore is not in line with the cylinder for some reason to me.

I assume you have checked the accuracy with factory ammunition.

If it were mine, I would be checking to see if the gun was in spec. After cleaning, check for endshake, and lockup.. I would use a range rod to check barrel/chamber alighnment on all charge holes, and check the diameter of the throats. Every gun I have checked except one had throats right at .357 with a + or - too little to matter. My 627-2 had one chamber that was .367. It would throw a bullet about 3 feet from the other five at 25 yards! Smith replaced the cylinder. Check the forcing cone to see if it too big or small. And check the muzzle to check for burrs or nicks. They can affect accuracy as well. A bent yoke could also cause the charge holes not to align with the barrel, that might have some influence on accuracy.
If all those things are good, it should shoot if the rifling is good. If you can't check all those, a trip back to the factory for their analysis is in order. The -4 should have the lifetime warranty.

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Richard Gillespie
FBINA 102

Thanks for all the help. Just cleaned it up and will follow up on your advice. Endshake and lockup seem fine but haven't done the other checks yet. I don't own a range rod but will ask a couple area gunsmiths. Love 686's and this is my only one drilled and tapped for a mount so it may end up with a trip back to S&W.

My 2.5 inch 686-4+ shoots like a laser. Groups the size of a quarter at 15 yards. Check for lead build up in the barrel, too.

....that is VERY unusual, but it doesn't mean that a 686 can't have enough flaws to render it inaccurate. I would be really curious to get to the bottom of what was wrong with it, beside the feeling that I bought a bum pistol that should be a jewel.

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"He was kinda funny lookin'"