Moderate loads for .357 magnum?

[Larry Gibson]

6 gr of Unique will pretty much duplicate 38 SPL+P with that bullet. I most often use 6.5 gr though. You might try both loads. You don't say what lube(?) so I suggest a good softer NRA 50/50 lube or BAC. LLA also works if 2 light coats are used allowing each coat to completely dry.

[derek45]

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

231, unique, and universal are all good choices

6" 586

158gr swc 7.0 unique 1237fps

6.1 win231 1117fps

6.4 w231 1151fps

[uscra112]

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.

Same here, using a 160 gr. SWC cast of 50-50 Pb/wheelweights with 1% tin added. 9 grains is mild, 10 grains moderate, 11 grains is snappy.

Blue Dot doesn't get the respect it deserves, IMHO.

[harbor2]

Appreciate everyone's help and advice. I tried 5 grs of 231. Decent accuracy but leaded the chambers, lead on the chamber end of the cylinder, forcing cone and about 1/2 inch up the barrel. Chronograph from 10 rounds was 848 fps. As I mentioned in my initial post the bullets are .358 with a mix 20x1 Desperado Bullets and a soft lube. Thinking now of trying .357 dia, I do have some old Meister bullets and are hard cast. I did use a expander M die and it's the ticket for straight seating the slugs, thanks Mr Gibson.

[harbor2]

I misspoke about the M die, thanks Petro Powder for your comments and the die does make it easier to get the bullets started straight. Mr Gibson and all who have shared, Thank you for sharing your time and knowledge, I truly appreciate it.

[rfd]

starline brass, 4.2 to 5.0 grains of w231 under a BBI 160 grain hi-tek coated #2 alloy lead bullet in a henry H015 .357mag rifle with 22" bbl - NO pressure signs or leading. bullets seated to within .020" of the rifling.

[sniper]

I just finished reading Patrick Sweeney's book "Reloading for Handgunners"; a good, informative read. His formula for "mild " 357 Maggies was: "Pick a .38 Special load, and add 10%"! I did some comparison, and that will result in a load about .38 +P, pressure and velocity...somewhat less powerful than the starting loads for the 357, depending upon powder. The comparison with 38 +P loads is hotter, but still below most starting load pressures for the 357.

[sniper]

Same here, using a 160 gr. SWC cast of 50-50 Pb/wheelweights with 1% tin added. 9 grains is mild, 10 grains moderate, 11 grains, snappy.
Blue Dot doesn't get the respect it deserves, IMHO.

My sentiments, too! (9.5 gr. Blue Dot under a 150-158 gr. SWC was very pleasant to shoot, but I didn't have a chronograph, so have no idea of the velocity. I shot up the last of a nearly-full bottle I bought from a co-worker for $5, and It sort of fell by the wayside.

[cwlongshot]

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.

I agree 100%

CW

[JoeJames]

I just finished reading Patrick Sweeney's book "Reloading for Handgunners"; a good, informative read. His formula for "mild " 357 Maggies was: "Pick a .38 Special load, and add 10%"! I did some comparison, and that will result in a load about .38 +P, pressure and velocity...somewhat less powerful than the starting loads for the 357, depending upon powder. The comparison with 38 +P loads is hotter, but still below most starting load pressures for the 357.

I agree with adding 10%. My good 38 Special with 4.1 grains of Win 231 and 158 grain SWC's average about 850 fps. I would start with 4.5 grains of 231 and see how that does. Backing off a tad from your 5 grains would be a fair test.

[sniper]

Duplicate

[JoeJames]

Duplicate

I am kind of puzzled here. I looked back through the other postings and did not find one specific reference to just plain old using 4.5 grains of Win231. I posted my advice since he indicated he had leading when using 5 grains of Win231. If I was in error posting this, I most heartily apologize.

[harbor2]

Thanks Joe James and everyone for the advice. I recently tried 158 gr. Rn and swc coated .358 dia. from Missouri Bullets. No leading but had to use Flitz to remove the baked on coating on the front of the cylinder and inside the frame. Might as well stick with gg slugs, easier to remove. I slugged and miked the cylinder chambers tonight and they all are a uniform .356 diameter. Slugged the barrel but with the 5 groove I can't get a decent measurement. The barrel slug though was a slip fit in all the chambers which is good. I did order a Lee sizer in .357 dia. and will size the lead .358 bullets and give that a try. By the way the coated bullets were accurate with 2 six shot strings, all touching from a rest at 15 yrs. Problem now if it don't quit snowing I might not get to the range till spring.

[crankycalico]

Try lubing the barrel with Johnson paste wax?

[Orchard6]

I too vote for Blue Dot. I run 10 grains behind a modified Lee 358-158 rnfp dropping a 150 grain hollow point with great accuracy. Another load my Blackhawk likes is the Lee 358-125 rnfp on top of 20 grains of 296 this would be a bit above a medium load but it shoots like a lazer!

[Char-Gar]

I applaud your search for a moderate 357 Mag load. There is no reason to stress these K frames Smith, unless their is a real need to do so.

I favor a 150 grain full wadcutter over either 5/Bullseye, 10/2400 or 7.5/AA5. This will all produce between 1,050 and 1,150 in your Model 66. You can of course use any nominal weight cast bullet you want. I am certain you can find an equivilent Unique load. I am thinking around 6.8 grains should do the trick, but I have not tried it, so your blood be on your own head.

[dale2242]

5 gr Red Dot with a 158/160 gr. cast....dale

[Murphy]

If you keep experiencing leading, my first suspect would be the cylinder throats. In your post, you state they measure .356 diameter from your slugging them. Having them opened up to .358 may solve your leading problem.

I was just telling a co-worker a couple of days ago, that one of the things I find enjoyable about reloading is finding the just right load for a specific gun.

Murphy

[Possumbelly220]

My go-to load is 6.1grns of Universal for a cast 158grn bullet. Super accurate in my 4 5/8 Blackhawk!

[Hick]

4 grains of Titegroup under almost anything