Moderate loads for .357 magnum?

[harbor2]

I am trying to find a moderate load for my Smith & Wesson M66 4 inch using the .357 case. I have 158 gr. SWC 20-1 sized .358 with a brinnel of 8 to 9. Powders available are Unique, Win 231 and Universal Clays. Of course my goal would be to get at least .38+p velocities maybe 900 to 1000 fps and not lead the cylinder and barrel. The Hodgon manual quotes 5 grains Unique as max for the 158 lead bullet. Web searches show 6 to 7 grs. and hard cast. Is it possible to get the velocity I want with these softer slugs?
harbor2

[Wheelguns 1961]

I use 6.5gn of unique with a 158gn swc cast of 50/50 wheelweights to pure. I haven’t chronoed it, but it shoots accurately. I believe that it is in the 1000-1,100 range. I have also used 5.0gn of ww231 under the same bullet with excellent results. Edited to add: bullets are powder coated.

[JSH]

Look at max book loads for the 38 special or +P, then look at what a start load is with same powder and bullet for 357.

As to speed and leading, your gun,alloy and lube will be the judge of that.

[marek313]

Thats pretty soft for 357 magnum but if you powder coat those they should work. I would use Unique for mid loads but I'm at work so I cant recommend anything specific.

[Thumbcocker]

4.5 of red dot worked well for me as a plinking load.

[harbor2]

Thank you all for your replies. As soft as these slugs are I will start with 4.5 grs Unique and go from there. I have never tried powder coated bullets.

[Petrol & Powder]

harbor2, I think 4.5 grains of Unique may be a bit too low in a .357 mag casing but there's no harm in trying. I doubt that load will even get you to 900 fps. Since you have 231 available, I would suggest something around 5.0 - 5.3 grains of 231.
I wouldn't worry too much about the alloy being soft. With a proper fitting bullet and a good bullet lube you should have no trouble with leading even at 8 - 9 BHn as long as you don't try to push that too fast.

Make sure your casings aren't swaging those soft bullets down even smaller than .358" And you may want to measure your throats; most S&W cylinders I've run across are closer to .357"

A Lyman "M" die of the appropriate size may also be useful.

Good Luck

[Petrol & Powder]

And just FYI:

http://www.lasc.us/Fryxell_Book_Chap...Metallurgy.htm

[harbor2]

harbor2, I think 4.5 grains of Unique may be a bit too low in a .357 mag casing but there's no harm in trying. I doubt that load will even get you to 900 fps. Since you have 231 available, I would suggest something around 5.0 - 5.3 grains of 231.
I wouldn't worry too much about the alloy being soft. With a proper fitting bullet and a good bullet lube you should have no trouble with leading even at 8 - 9 BHn as long as you don't try to push that too fast.

Make sure your casings aren't swaging those soft bullets down even smaller than .358" And you may want to measure your throats; most S&W cylinders I've run across are closer to .357"

A Lyman "M" die of the appropriate size may also be useful.

Good Luck

Thanks for the reply Petrol & Powder, I will try Win 231, it definitely meters better than Unique. I need to read up on the Lyman M die particulars. I have Lee dies with the extra factory crimp die. Now that you mentioned to watch the case size in reference to the soft bullets, maybe the fcd die might not be usable. Will have to see, thanks again.

[robg]

7 gr true blue works well ,meters well and clean

[Petrol & Powder]

I'm not a fan of the Lee FCD but that's a personal opinion. It's also not the relevant issue here.
It's easy for a an improperly sized casing to swage a soft bullet down to a smaller diameter. A lot of expanders that work fine for jacketed bullets are not as well suited for cast lead bullets, particularly if the bullets are soft.

When the casing is expanded the brass will spring back a little after the expander is removed. Ideally you want the casing to provide a little bit of neck tension without so much that it swages the bullet. For a .357" -.358" lead bullet, a .357" expander works fairly well. The casing will spring back to about .356" and that diameter coupled with a roll crimp in the crimp groove will prove good results.
Add that neat little Lyman "M" die "step" that really helps to start the bullet squarely in the casing and the whole system works nicely with cast bullets that have a crimp groove.

[Petrol & Powder]

I just measured the expander plug on my Lyman "M" die for 38/357 and it's .356" with a step of about .360"

The plug is removable and you can get different sizes.

I had Lathesmith make a couple of Dillon powder funnels (Insert BIG endorsement for Lathesmith here) and they are .357" with a .360 step.

[rintinglen]

6.0 grains of WW-231, 6.5 Grains of Unique, 7.0 grains of Power Pistol: any of these will make for a nice medium .357 158 grain load in the 1000-1100 FPS range.

[eddietruett]

I shoot a lot of coated 158gr TCFP and SWC with 5.0gr of Universal. I did chronograph some but can't find my book, but I think it was giving me around 950 out of a 8 3/8" Model 686. I shoot a lot of steel plates and 75 yards which is the limit to my home range. Very Pleasant to shoot and extremely accurate. Was using Unique but the Universal meters better in my Dillon press and seems to shoot a little cleaner. I have used a very similar load of Power Pistol listed by rintinglen above with very good results as well. I shoot most of mine in 38 special cases and use in .38 and .357 Revolvers. More of a +P .38 load

[harbor2]

I really appreciate all the replies for finding moderate loads for my .357. Now I just have to get out and do some loading and range work. I have a Lee hand press and dies coming in the mail, should be here soon. In the mean time, my grandson and I are taking this week to go reindeer hunting on Atka Island, Alaska. Wish us luck.

[Walks]

Good Luck on your Hunt.
LYMAN M-dies are the best dies for expanding a case for a cast bullet. The 2-step expander has been sold by LYMAN for over 60+yrs.
I don't care much for LEE dies either. I discovered their Factory Crimp die was actually squeezing the bullet Diameter of bullets seated & then Crimped with a FCD from .428dia down to .426dia in my .44-40. And .401dia bullets in a .38-40 down to .398dia, I don't use them anymore.
Good roll crimp is the best way to hold a bullet for good powder ignition.

I don't know what manual you are using but it's been a WHOLE LOTTA YEARS since HODGDON published a manual showing Alliant/Hercules powders like UNIQUE.

Are you sure you're reading the right line?
I would you suggest you use data from only the HODGDON (Winchester, IMR, HODGDON powders) or the ALLIANT website.
Perhaps buy a copy of the LYMAN CAST BULLET HANDBOOK #4 or one of the caliber specific Loadbooks covering .38spl/.357mag.

[rfd]

i load 4.7 to 5.0 grains of w231 under an acme or precision hi-tec coated 125 grain bullet for my S&W model 60 snubbie. easy going on recoil, pretty accurate, too. now i need to figure out what to load for a companion .357mag rifle ...

[HBAR2989]

I stumbled on 10gr of blue dot 25-30 years ago. For a mid range load it has been the most accurate load I have used.

[Ed_Shot]

Red Dot / Promo 5.0 gr. under a 120~160 gr boolit in a .357 case is my standard mid-range load. Economical, and the accuracy is hard to beat.

[sniper]

For years, I shot IPSC with my 4" Smith & Wesson 586 ...5.5 gr Unique, 357 brass, standard primers, RCBS 150 gr. SWC boolit, home cast with what I hoped was somewhere in the neighborhood of Lyman #2 alloy, from my Coleman camp stove, which is supposed to be ~ BHN 15. Lubed with some red stuff Lee packaged with its pan lubing outfit. 860 fps, chronoed, no leading to speak of, easy to shoot. 9.5 gr. Blue Dot under 158 cast boolits was also nice to shoot and accurate. Since the prohibition against 125 gr. boolits/Blue Dot, my use of has gone by the wayside, but I still see current loading manuals showing use with 125 gr. projectiles. (?) Good luck with your search. Some very good suggestions have been offered.