Here is a verygood deal on N32C pistol powder. Some say it works verygood in 45acp. I ordered 4 lbs, good service, with tracking number.
Browsing Store - N32C 1# VIHTAVUORI Powder
Looks like your 686 6" pistol is shooting verygood. When was this gun manufactured. The newer -6 versions with lock are a little different from my -4 version. Biggest difference i noticed was trigger felt farther forward in the newer -6.
According to Handloader issue 285 August 2013:
Accrate #9 is a favorite in the 41 Magnum, especially when used in everyday working or hunting guns, as it duplicates or exceeds factory load velocities with standard weight bullets, gives excellent accuracy but also less muzzle flash and noise...
I have been using Tin Star N32C powder lately with verygood results. Hardly no loading data for it...you will need a Chroni to test.
Browsing Store - N32C 1# VIHTAVUORI Powder
5.7gr gives me 1010 fps in my 357 magnum using 158gr lead bullets
9.0gr gives me 900 fps in my 45 lc using 220gr lead...
I size my bullets .001 larger to reduce gas/flame cutting. The throats of my 686 measure .3575, so i size slightly over .3580. The tighter the bullet, the less flame cutting or lead spatter on cylinder face and inside of cylinder. NRA 50/50 lube should work better also.
BTW my 686 never liked...
Commercialy loaded lead rounds are your biggest problem. You need to reload and size bullets to .3585 and use 50/50 lube. Keep velocity around 800-900fps.
Fine 0000 steel wool is OK to use for removing lead. Wrap wool strands around .357 brush then scrub. Be careful around crown of barrel
Mixed brass will have mixed hardness and thickness. This is the reason some of your brass will not chamber and some will. Annealing will help even things out some, but you should allways uses brass from same lot to get equal sizing.
I like the softer Remington brass, because it does not spring...
LBT wide flat nose designs are best for killing power and good accuracy. I like the "gas check" .358 diameter versions.
Rim Rock and others sell these, but make sure you are getting atleast 3580" diameter and not smaller.
The 180gr LBT WFN will give you more penetration. The gas check version will help guard against leading of barrel at higher velocities.
Rim Rock Bullets | Cast Lead Bullets ~ Right on target!