Growing up my brother had a 6" bbl'd python. Excellent revolver!!! He shot a mix of reloads with most of them being 38spl/target loads.The python would make it to 20,000/25,000 rounds and then need to be sent in to be rebuilt. When I got older and wanted to buy my own 357 I talked to my brother about what's out there. He brought out a 6" bbl'd nickel 586 and said he retired the python after the 2nd trip back to colt to get rebuilt. Something about colt was going to quit working on the pythons.
Having shot countless 1000's of rounds in the python we went to the range and my brother let me use/shoot the 586. Needless to say I was extremely impressed with the s&w and ended up buying a 6" bbl'd 586.
Accuracy wise I couldn't tell the difference between the colt and the 2 s&w's. I could tell the difference in the longer cylinders of the s&w's, i could load/shoot bullets/357 cases in the s&w that I couldn't in the colt. I had that 586 for decades and shot a lot of hot 357 loads in it. Pat's reloading was right down the road and the 32# cases of the wc820 were cheap. Couple that with free range lead for bullets, that 586 saw a lot of use. Sent it back to s&w when it had over 100,000 rounds down the tube. They rebuilt the timing in 1997. Shot another 100,000+ in it and sent it back in 2006/2007? They rebuilt the timing again and this time re-cut the forcing cone. Finely last year the bbl gave up the ghost. Loads that I used for decades in that 586 were doing 50fps/60fps less than they did before. The bbl was shot out.
Ended up buying a new 686 with a 6" bbl.
Wanted a load for it to use on the bowling pin table. We setup 12ga shotgun shells instead of bowling pins. And shoot the shotgun shells @50ft instead of 25ft. So I did some test loads with that 686 pictured above. They were only 6-shot groups fired @50 using a rolled up piece of cardboard with a towel on it sitting at a table for a rest. I'm sure a Ransom rest would of did better. But I did manage to come up with these loads.
I retested both loads with a 50-shot string and both of them shot bugholes in the targets. I know I only did the testing @50ft looking for a action shooting load. But I have put both those loads on paper @25yds and 50yds and they have no problem shewing the x-ring out of nra targets. That 686 that I bought last year is a lot more accurate than I am.
On a side note:
They didn't put the colt bbl's on a s&w because they were better. They did it because of the difference in twist rates and the longer bodied wc/hbwc bullets. 3 different 148gr bullets, a wc (left) and 2 different hbwc's (center & right).
Longer bullet ='s faster twist. The s&w's had a 1 in 18 3/8's twist. The colt's had a 1 in 14 twist. It was more of a target velocity bullet rpm, stability thing. The 686 next to a dan wesson 15-2 that has a custom 1 in 10 twist bbl, heavy bbl shroud and a muzzle break. The dw is setup for the longer/heavier full house loads using 170gr/180gr bullets.
A schneider built ppc revolver that that has a 1 in 16 twist in it. He made the long standard cylinder version on this ppc pistol like the 1 pictured below.
Schneider also did a 1 in 16 twist ppc revolver with a patented short cylinder that was designed to shoot flush seated 38spl wc ammo.
Anyway My brother took me to the ranges with him and I used/shot his python for over a decade. I've owned 586's/686's for almost 3 decades. With 40 years of hands on shooting with both firearms I would have no problem buying/owning/pitting a 586/686 against a python.
Personally, any 3 of those pistols pictured above will give a python all they can handle. I can afford to own/use/shoot pythons, I just feel they are outgunned and you can see where I put my $$$. Better triggers, longer cylinders & stronger longer lasting actions with no loss of accuracy.