.357 Throats and .357 Barrel - Advice, please

[Low Budget Shooter]

Fellars,

My brother has loaned the kids and me his old match revolver, "Frankenpistol." It started life as a S&W 681, but in .38 Special. It has a custom slab-side 6" barrel. The action is wonderfully smooth. He shot jacketed in it, but I can't afford to do that! I slugged the barrel and throats---they are both right at .357

I'm not a newby, but I don't have any experience with a revolver where I can't get the bullet to enter the barrel .001 or .002 over.

Would you advise me?

The dies I have give me the choice of .3575, .358, or .3585 What would you use?

Should I use a nice soft alloy, or hard?

Does shape of bullet matter?

I understand that the only way to know for sure how to get this gun to shoot is to try it. But I'd like to hear the voices of experience first so I can know what is likely to work.

Thanks!

Jeff

[DougGuy]

As far as alloy, start in the middle of the road. If you are shooting .38 Spl loads there is no need for a really hard boolit, unless the gun itself takes a liking to a hard alloy. Trying it and seeing the results will tell you more than just talking about it on the forum that's for sure. Far as sizing goes, can you push the .3575" sized boolit into the front of the cylinder throats with your fingers? That would be a good fit. Some loads won't chamber all the way if the boolit is larger than the throat diameter. Again you have to try it and see what will chamber, if it won't fully chamber, you won't be able to shoot it so that part may decide itself for you.

[williamwaco]

If your slugging is accurate.

You can try the .3575 dies but I would expect the .358 to be optimum.
I am 99% sure you will not be able to tell the difference..

Slugging accurately can be hard to do on a S&W with the 5 groove barrel.
Your custom barrel may have an even number of grooves and will be easy to slug accurately.

Note that sizing dies rarely size bullets to the exact size they are marked. Size a few and measure the sized bullets.

.38 special hollow based wadcutters that I have tested measure about BNH 5 to 6.

I use BNH 8 to 9 if I mix my alloy and have enough pure to get it that soft.
More often I am using wheel weights and they usually test BNH 12 to 13 and occasionally as hard as 15.

Long Story short - Hardness doesn't matter. Fit does. If you get leading, go to the next larger die.
Leading is relative. You will very likely get some leading.

See pictures here to get an idea of light vs heavy leading.

http://reloadingtips.com/pages/leading-degrees.htm

http://reloadingtips.com/pages/leading-zero.htm

http://reloadingtips.com/pages/leading-severe.htm

[SSGOldfart]

size to.3575 and use a number 2 alloy you might what to push these a little softer then 38spl loads remember it's a target gun set-up,I bet the kids will like a WC better then a hot load too