Lee 358-140-SWC in 357 magnum

[Bazoo]

The only mould I have for 357 is the lee 358-140-SWC. I have powders unique, 296, IMR4227. Does anyone have data suggestion for this bullet? Or the suggestion of a bullet that takes up the same case volume and is similar in weight?

As a side note, lee moulds suck because there is no data for them. It's what I have at present though.

[tazman]

What kind of power level are you looking for?

[Larry Gibson]

Data for the Lyman 358477 will work fine. I suggest Unique of the powders you have. Just start low at the start load and work up to the max load unless pressure signs arise or accuracy goes south as we are supposed to do.

[Bazoo]

Thanks for the suggestion Larry. I was figuring on unique being the easiest and safest to work with of those choices.

Tazman, I'm not sure. I have a good 38 special load worked out, so now I'm going for a magnum loading. It needs not exceed factory ammo pressure as it will be fired through a 686.

[tazman]

In that case I suggest the same as Larry did about data for the 358477.
The only difference I would make is to suggest you look at a couple of different powders. You can get close to max velocities using a number of powders that are easier to run through a measure than Unique is.
Check loading data from the manufacturers for any 150 -158 grain boolit and you will be in the ballpark.

[Bazoo]

The only powders I have to work with are what I listed. I run unique through the my lee perfect powder measure acceptably.

I was hoping for some 296 suggestions but I'm content to get a bullet suggestion to help load work up with unique. I want other moulds but right now this is what's in the budget.

[JM7.7x58]

Bazoo,

I have settled on using 13gr of 2400 with the 358477, in .357 Mag cases.

Alliant 2400 has become a "utility powder" for me. I use it in three different calibers .357 Mag, 30-06, and 7.7x58mm.

JM

Edit: Lyman 3rd edition Cast Manual has this load for the 358477 with IMR-4227 starting 11.8 grains to max 16.0 grains.

JM

[AlaskaMike]

296 will work, but 140 grain is getting on the light side for that powder in my opinion. 296/H-110 is great for getting higher velocities, but when you start going lighter than 158 grain bullets it starts to get really "blasty" with a big fireball and report. 4227 should work great in your situation.

You might try loading some with each of the three powders you listed though, and see what you and your gun like best. One of my favorite loads in my 4" model 28 is the RCBS 150 grain SWC over 7 grain of Unique. Not a magnum load, more of a midrange but noticeably more than .38 special level.

[Bazoo]

Thanks for the replies. I'd like to use 296 as it's magnum specific, but I'm afraid of it. All I've ever read on it says not to download it, and not having data specific for my bullet I'm uncertain where to start. I know the characteristics of unique are a lot more forgiving at that end so I'm inclined to go that route. I was kinda hoping someone else had already figured out a 296 load and would share.

I used 358495 wadcutter bullet data for my 38 starting point as it goes deeper in the case. That bullet is listed in 357 mag data but not with 296.

[Bazoo]

Could someone measure an RCBS 150kt bullet for me? I'd like the length from the base of the bullet to the crimp groove. It looks similar in length to my lee so I'm thinking it may help me determine a good starting point for 296.

[Tim357]

Thanks for the replies. I'd like to use 296 as it's magnum specific, but I'm afraid of it. All I've ever read on it says not to download it, and not having data specific for my bullet I'm uncertain where to start. I know the characteristics of unique are a lot more forgiving at that end so I'm inclined to go that route

Not to hijack your thread, but if you have Lyman CBH #3, look at the loads for H110 vs WW296. H110 shows quite a spread betwixt start and max, whilst 296 says do not reduce. It's a mystery to me...

[Bazoo]

No worries of hijacking.

I have noticed the discrepancies between 296 and h110. I've never loaded it before so I don't have any personal experience with it's characteristics. I bought it 4-5 years ago when powder was still scarce. I wouldn't be fraid of it if I had data specific to my bullet, or a bullet I knew was similar in case volume.

After looking again at the bullets in reference I don't think the 358477 is close enough but I think the 38-150-kt is and might start there. I still would like a measurement from one though if someone was willing.

I prefer 2400 but ain't got any on hand. 2400 is forgiving at both ends of the spectrum according to both my research and my experiences.

[Wally]

I have used it in a Ruger BHK and a S & W Mo 27....4.5 Bullseye gets me 1,030 FPS....I use it as a medium magnum load. Std deviation are 21 FPS in the BHk and 6 in the Mo 29. It is very accurate and I have found that no 150~160 SWC cast bullet is any better at that velocity.

Use a loading block and double check charged cases with a flashlight so you don't double charge...

[Bazoo]

Thanks Wally. I will keep that in mind. I do use a load block and visually check when loading.

[JM7.7x58]

No worries of hijacking.

I have noticed the discrepancies between 296 and h110. I've never loaded it before so I don't have any personal experience with it's characteristics. I bought it 4-5 years ago when powder was still scarce. I wouldn't be fraid of it if I had data specific to my bullet, or a bullet I knew was similar in case volume.

After looking again at the bullets in reference I don't think the 358477 is close enough but I think the 38-150-kt is and might start there. I still would like a measurement from one though if someone was willing.

I prefer 2400 but ain't got any on hand. 2400 is forgiving at both ends of the spectrum according to both my research and my experiences.

The load data for the 358477 should be just fine pressure wise, because of the following statement from the Lyman 50th edition.

Lyman 50th edition, Page 416, 357 Magnum, third paragraph: In order to maintain a maximum overall cartridge length of 1.590", it is sometimes necessary to crimp cast bullets on the forward edge of the front driving band.

Lyman 50th edition, Page 418, 357 Magnum, 358477 load data: 1.510" OAL

My 358477 mold drops a bullet that is .660" in length. If I seat it to a 1.510" OAL then .440" of the bullet is inside the case. The crimp groove is inside the case, it is .125" inside the case. This bullet is seated very deep if you use the Lyman 1.510" OAL. The Lyman data is written this way because some .357 revolvers cannot chamber a round that is longer than 1.590. The Lyman Load Data is explicitly written with the assumption that the 358477 is going to be seated an 8th of an inch deeper than most of us will seat it. The pressures Lyman lists are based on this reduced case capacity.

I seat to the crimp groove. Loaded to a OAL of 1.625" they work just fine in my Ruger Security Six.

As long as you seat to the crimp groove on your Lee 140gr bullet you should be fine pressure wise.

JM

[Bazoo]

Thank you JM, that's very helpful.

I think I will start with RCBS 38-150-SWC data however. Taterhead was nice enough to measure one for me and from the base to crimp groove was .360 and my lee measures .355. So it's very close in both volume and weight.

[Mr_Sheesh]

A PDF of the Lyman Cast Bullet Handbook 3rd Edition (1980) is free on Archive.org

[Bazoo]

Thanks Mr Sheesh.

[ddixie884]

Yeah cool, thanx.....

[AlaskaMike]

I get a little nervous about relying on data from Lyman's Cast Bullet Handbook. I have #3 (eleventh printing, dated 2002). Some of the load data published in that manual is pretty scary. A great example is the max load they show for .44 magnum using #429421 with 2400 powder--23.4 grains. You couldn't pay me enough to load that, and no other authoritative source of load data goes nearly that hot. Even old Elmer topped out at 22 grains.