variables in reloading 357 magnum

[FredGarvin]

Hello all - just shot my first ever 25 reloads (357 mag). Very much fun, soft shooting, and pretty accurate (for me), better than factory (all 25 rounds, 2" group, off-hand, high/left, . However, dirtiest rounds I ever fired through my S&W 686 4". Some visible specs of unburnt power in the cylinder. The loads were the minimum, straight out of the Lee Manual, as follows:

Brass: once fired factory Winchester
Primer: CCI 550
Powder: IMR 4227, 15.0 grains
Bullet: Hornady 140 grain JHP
light to moderate crimp, 1.57 to 1.58 OAL

On the brass, a ring of soot is visible where the top of the breach face meets the shell casing. I won't be reloading this brass again.

With all of the possible variables that I could change, which should I mess with first to try to get the rounds a little cleaner. Thanks for helping a newbie, and thanks to everyone for all the help getting me this far.

[Terry Murbach]

YOU CAN LOAD THAT BRASS UNTIL THE COWS COME HOME. CLEAN THE POWDER STAINS OFF AND HAVE AT IT. I HAVE 357MAG BRASS IN CONTINUOUS USE SINCE 1967 AND FOUR[4] OF THEM FROM HUNDREDS HAVE CRACKED OVER THE YEARS.

[J Miller]

From my limited experience with it, 4227 is one of those powders that don't like to be loaded light. Once you get it up to it's sweet point it will burn cleaner. Soot on the outside of the cases is a sign of too low pressure. There isn't enough pressure to expand the cases to seal the chamber.

I'm not sure where your data came from but if you can bump it up a bit and see if that cleans it up a bit.

Joe

[Hobie]

Yep! Crimp her a bit more, too.

[Nath]

You guy's know more than me but would it be better to have a faster powder than this fast rifle powder? In this length of barrel I mean!

Nath.

[Lefty Dude]

Tight roll crimp and your good to go.

[J Miller]

Nath,

Somebody many moons ago did some tests that showed the slower powders like 2400, IMR/Hog 4227, and so forth still gave better velocities in the shorter barrels than the faster burning powders. I don't know who or when or where any more, so I won't swear to it.
I do know that the faster powders reach their pressure peak sooner than the slower powders so their ability to reach high velocities is limited.

Joe

[Nath]

Thanks Joe It was just how I was understanding this application which is also based on no experience so I guess the lesson is; don't dismiss anything Nath!

N

[COSteve]

From my limited experience with it, 4227 is one of those powders that don't like to be loaded light. Once you get it up to it's sweet point it will burn cleaner. Soot on the outside of the cases is a sign of too low pressure. There isn't enough pressure to expand the cases to seal the chamber.

I'm not sure where your data came from but if you can bump it up a bit and see if that cleans it up a bit.

Joe

Yes, both 4227 and H110 both burn cleaner with heavier charges and a good, strong crimp.

[Pisgah]

Up your load to the max given. Give 'er a good stout crimp. Enjoy!

[Chuck 100 yd]

What those guys said +1

[FredGarvin]

Thanks for the good advice.