581
Here's my ex-police 581 with grips either modified by the cop, or by another owner who had it later for easier use of speedloaders. I also like to put together "rigs" for all my police guns, and have the perfect one for this revolver, with a 3-pouch speedloader set with some older HKS loaders for the 586. I am debating whether to add some square butt Magnas and a Pachmayr grip adaptor or leave it as is......I have a set of the "large" Pachmayr grips but I do not like the look of rubbers on a blued gun........hmm, an excuse to get a 681!! I love the L-Frame .357's, that beefy cylinder has lots of meat around the chambers, and it feels like a "real gun" heavy, beefy and all steel. Makes my K-Frame 4" .38's feel like pocket revolvers. I'm a huge fan of fixed sight 4" S&W's like the M10-M64, and my 581 feels like a Model 10 on steroids.
A 681 chambered in .38 would be awesome, just to have something "different". I shoot mostly .38's in my .357's anyway, I would imagine a 581 or 681 fired with .38's would just about last forever, heck it would last forever with .357's! Shooting light .38's in my Dad's 6" 586 feels like shooting a .22, it's a classic example of a duty gun built for constant use of hot .357 service loads.
I also have the Ruger "version" of the 581, as I compare them, the 4" full lug fixed sight GP100, mine is chambered in .38 Special.
I am looking for a police trade in 4" 586, also as a stainless fan I "need" a 686 and 681!
Of all the S&W's the 586 6" has the most "sentimental" value for me, it's the first handgun I fired as a kid, my Dad still uses it as his "bump in the night" gun. I am usually not a fan of full lug 6" revolvers but somehow it's perfect on the 586-686 revolvers.