Advice on 357 Mag CB load with W296?

[xsquidgator]

I've been making and shooting 158LSWC from the Lee mould (tumblelube) for awhile, using W231, if I recall correctly somewhere around 5-6 grains of W231. But, I have several pounds of W296 on hand for M1 30 Carbine loads and I'd like to try 357 magnum with W296. I even have some CCI #550 magnum small pistol primers.

Here's the rub- lack of data for 158LSWC and W296.
1) Hodgdon.com lists a line entry for 158LSWC and W296, but the amounts of powder and other info for that load are blank.

Out of several manuals I have, only two have data, and it's not really consistant data:
2) Lyman Cast Bullet Handbook says 18.0 grains W296, COL 1.590", should be 1461 fps and 41,400 CUP. And it says that reduced loads of W296 are not recommended, which jives with what I've heard and read other places.

3) Lee #2 guide says 14.5 grains W296 max for 1560 fps and 38,000 CUP


Which is right, the Lee #2 load (14.5 grains) or the Lyman CB book load of 18 grains W296?

I've looked around on the board here and haven't found the exact answer, yet.

http://www.castboolits.gunloads.com/showthread.php?t=34623&highlight=w296

http://www.castboolits.gunloads.com/showthread.php?t=29315&highlight=w296

[fastgun]

Stick to your 231 load. The reason there is not a lot of data for 296 with lead bullets in a 357 mag. is probably because it is not the best combination.

[fredj338]

Using starting jacketed data for lead is a pretty accepted practice when working w/ jacketed data for lead bullets. So 15gr & work up. Expect some leading depending on your alloy & I'm not sure the small amount of Alox is going to give you much protection, but the only way to know is shoot some.
158 GR. HDY XTP Winchester 296 .357" 1.580" 15.0 1418 28,600 CUP 16.7 1591 40,700 CU

[xsquidgator]

Stick to your 231 load. The reason there is not a lot of data for 296 with lead bullets in a 357 mag. is probably because it is not the best combination.

It may well not be, and for general plinking my W231 loads are ok. But I would really like to be able to make a cast boolit load that comes closer to the "357 experience" with respect to boom, flash, and recoil. Mostly for funzies, but I'm also kind of scientifically curious about this. I've read that W296 is the powder that Winchester loads its commercial 357 ammo with, and goshdarnit I really have the bug in my bonnet to try it.

I think there's a chance it'll work ok anyway. I water quench wheelweights and have gotten them up to 1850 fps in my M1 Carbine without any trouble, I'm optimistic that I can get a big booming ok load out of this. I'm just the slightest bit concerned about whether to go with 14.5 or 18 grains of W296, since there are these cautions about not reducing W296 loads. A 357 case won't be full at 14 grains but it'll be at least 1/2 full...

[xsquidgator]

Using starting jacketed data for lead is a pretty accepted practice when working w/ jacketed data for lead bullets. So 15gr & work up. Expect some leading depending on your alloy & I'm not sure the small amount of Alox is going to give you much protection, but the only way to know is shoot some.
158 GR. HDY XTP Winchester 296 .357" 1.580" 15.0 1418 28,600 CUP 16.7 1591 40,700 CU

Thanks Fred!

Thinking on it, the book and Hodgdon data on 140JHP was around 17-18 grains of W296, so 15 grains for a cast but 18 grains heavier bullet (158) sounds better to me than going up to 18 grains of powder.

[bobthenailer]

14.5 to 15.0 of 296 seemes about right

[high standard 40]

I would hold that load of 18gr suspect. That seems too hot based on my past experience. I would do as suggested by the previous poster and start at 15gr and work up.

[Mugs]

RCBS Cast Bullet Manual- 38-158 SWC 16.0 296 1190 fps. 17.0 296 1247 fps. shot from a 6" Ruger Security Six. shows cci#550 primer. Hope this helps.
Mugs
IHMSA 5940L

[MtGun44]

16.3 of H110/W296 does extremely well with 358429, RCBS 150 SWC and Lee 158 RF in several different
.357 Mags. Top vel and top accy with zip leading, using LBT blue and .357 Max's lube that
I have dubbed "RedMax".

Bill

[GLynn41]

15 should be good-- I have 16 no problems in a early model tight chamber DWA and a a 158 jsp-- so you should be good-- your milage will vary- let us know how it does go

[captaint]

I don't think 15 grs would be formally considered a "reduced" load. I mean it's not 7 or 8 grains. You won't have that much air space in the case with 15 grains. Give her a go!! Enjoy Mike

[xsquidgator]

Thanks everyone! I think I'll load up some with about 14.5 or 15 grains W296 under 158LSWC and see how they shoot this weekend. Appreciate everyone's input!

[Big Boomer]

Check specific handbook recommended loads for H110 and W296. See where the base of the boolit would seat with such recommended loads. What you will find is that the base of the boolit will just touch or will slightly compress such charges.

A practice I have used (but for obvious reasons can not necessarily recommend for anyone else) is to measure to that point to which the base of the boolit would come from the mouth of the case when the boolit would be seated. I. e., hold the boolit alongside the case with the case mouth exactly at the crimp groove. Fill the case to that point where the base of the boolit would come when seated with H110 or W296. Pour out the powder and weigh it. That is my desired load, generally. In some cases I add just a bit more powder in order to slightly compress the charge to achieve greater accuracy, though some loads do not require it. The objective is to eliminate excess air space, which is why reduced loads are not recommended with powders like H110 and W296. If you have a dial caliper, use the caliper to measure the distance from the crimp groove to the base of the boolit. The rod that sticks out the bottom of the caliper will give you the exact distance from the mouth of the case to the top of the powder charge. To some degree it is extrapolation but it works for me. 'Tuck

[gasboffer]

You may have to use a gas-checked bullet. I used a Lyman 358156. Worked very well.
IHMSA70L

[MtGun44]

Properly fitted with a good lube, no gas check is necessary in any .357 load that I have
tried. I am steadily heading towards the opinion that gas checks are either unnecesssary,
a bandaid to cover poor boolit fit/lube/hardness issues, or that they are really only
needed for rifle loads above some certain velocity.

Bill

[xsquidgator]

Re: gas check, I might do some cream of wheat filler on top of the W296, if there's enough room or any room left. Based on how full (or not full) the 357 cases were when I loaded them with 17.0 W296 under 140JHP, I think there will be enough room under the 158LSWCs to put in some cream of wheat to eliminate and remove leading.

[xsquidgator]

Update on the situation: I loaded up some 158 grain lead bullets (158LRNFP conventionally lubed ones that I bought a long time ago, seeing as how I didn't have any lubed home cast ones made up). So, I ran these through a 2.5" barreled Ruger SP101 on Saturday.

14.5 grains of W296 under these 158LRNFPs shot just fine, measured at 1032 +/- 32 fps out of the snubnose. No leading at all, which really excited me since I almost always get leading with cast bullets. Ran a wet boresnake through one time and the bore was clean as could be, fantastic.

I also made up a couple dozen of my home cast 158LSWC (totally unlubed, I forgot why I never sized and lubed them) with about 0.3cc (half of the smallest Lee powder dipper) Cream of Wheat filler on top of 14.5 grains W296. This looked by eye to be just enough to fill up the case volume between the powder and the bullet base. These shot ok too and as I expected, no leading when I use Cream of Wheat. All empties ejected easily. Some of the primers looked a little flattened, at least the radius around the edge of the primer was flattened out some, but no cratering or piercing of the primer.

So, I think 14.5 W296 will do ok. I have a 6" Blackhawk that I will have to try these out of next, with such a short, inefficient 2.5" barrel I find it really hard to tell if the rounds are performing the way they should.

[Lutzy48]

Late responding to original post. I too have noticed that the Lee and Lyman books show fair differences between what are assumed to be the same bullets. The eason is that the Lyman book's loads use magnum primers and Lee's loads are based on standard primers.