size 357 or 358?

[Doc - J]

Should I size my 158 gr. LSWC to 357 or 358? ( useing the lee TL mould)
I know Im picky but try to make the best load for different guns, and would like to have some sort of standard. (( better then just using them as cast.))
Your thoughts?

[cbrick]

Rather than "one size fits all", slug your bores and size accordingly. Conventional wisdom says to size .001" over bore diameter but my preference (depending on the caliber and alloy BHN) is .0015" to .002" over bore diameter.

Good examples: My 308 bore is .3075". My 30-30 is .3092".

One 30 caliber size just wouldn't do. Bores vary, sometimes a lot.

[mooman76]

You would either have to try the bullets in different guns or slug the barrels to figure out. I think most people go with 358 so I would start there. Are we talking pistols I assume? Some people don't even size for pistols and just use as is out of the mould which I find myself doing more and more for pistols anyway unless the size is way off!

[mag_01]

I size my Boolits at .358 for 38s and .357

[Doc - J]

Ok, guess I should order the 358 sizer and not the 357.... I have shot some 'AS CAST' 9mm that were comming out at 357 and the group was bad from a 38/357 ( they were also 30 gr. lighter, although thur a 9mm were ok. Since I have a 356 sizer guess that a 358 would be the next overall sizer I should get.

The love of casting is a art...wish I could shoot better.

[Paul B]

Interesting. you mention 9MM so I'll address that round. I have three handguns in 9mm and two of the three have a .357" bore while the other is right at .358". I think the first thing you should do is slug the bore of the 9MM. I've also seen some 9MMs that had a .355" bore, but not too often. If a boolit casts out at .358", try seating it in a case and see if it will chamber, if the bore is .356/7", they should shoot fairly well. They do for me and I get away with a boolit sized to .359".
If you're also shooting a revolver, things get a bit more complicated. Theoretically, a .38 SPL./.357 Mag. bore should run .357" I once had a Colt Trooper than ran .356". Assuming you bore has checked out with a groove diameter of ,357", then slug the cylinder throats as well. They should be a but larger than the groove diameter of the barrel, by at least .001", and I prefer .002". Bullets sgould be sized to match the cylinder throats, assuming they are the proper size. If the throats are too small, you'll get leading and poor accuracy as the bullet will be swaged down to a size too small for the bore. Fixing that problem will take a bit of gunsmithing.
Paul B.

[BruceB]

I size ALL my .38 Specials and .357s in a "nominal" .359" die, except for the special situation of our S&W Model 52 wadcutter-only autoloaders, which get .356" boolits.

My results are very fine, with excellent accuracy and zero leading problems.....but our four .357s and two .38 revolvers are all S&W manufacture. They span about fifty years of production, so keeping consistent dimensions over that length of time is an achievement. I have never measured throats or barrels, because the guns just don't give me any trouble at all. That's a big relief, because I'd hate to try keeping separate loads for each gun.

I've had better 9mm results with .357" bullets than anything smaller. Some guns-and-brass combos may choke on such ammo, but we have three 9mms which all work well with these boolits(a Ruger P95 and two Firestars).

[Leftoverdj]

What BruceB said. I've never gone wrong with .359 in a revolver, and I have never been satisfied with .357. An exception will come along one of these years, but it hasn't yet.

[Lloyd Smale]

Ive kind of standardized on 358 for the .38s and 357 for the 9mms but there are exceptions with my guns and some like them a tad bigger and none like them smaller.

[DPD]

Bigger is usually better provided you can get them to feed in auto loaders.
I have a Smith 39-2 with a barstow barrel (.355") that chokes on anything over
356.5" . Barrels are like food and wine tasters, they all have individual palates.

[arkypete]

Bigger is usually better provided you can get them to feed in auto loaders.
I have a Smith 39-2 with a barstow barrel (.355") that chokes on anything over
356.5" . Barrels are like food and wine tasters, they all have individual palates.

Check your cylinder mouths.
I use .359, .3585, some where around there, for my two 357s. But I use a relatively light load of 4.5 grains of Bullseye, the bullets are air cooled and lubed with LBT Blue, in a 357 case.
Jim

[rbstern]

Unless there is a specific problem identified that requires something different, I size all of my 38/357/9mm at .358. I use Lee's 358-105 SWC interchangably in both 38 special and 9mm as my paper punching bullet. Gives good accuracy out of any gun I've tried them in.

[Char-Gar]

Doc... Here is a secret. Shoot sixgun bullets as large as you can and still have them chamber in the revolver with ease. When they exit the cylinder throats they will the exact size of each throat.

So..you see.. you can size those bullets in the sixgun and not the machine. It won't cause any pressure problems... UNLESS... you are shooting rock hard alloys at red line/max pressures and then you might tip over the edge..but smart folks don't go near the red line.

A sizing die of .358 will give you bullets larger than most SMith and Wesson throats, but you can find some Colt throats that go .359. So a sizing diamter of .358 to .359 will pretty well take case of most needs.

If you Lee TL bullets when loaded in ammo, will chamber freely in your sixgun then just shoot them as cast.

[boogerred]

like charar said,358 is too large for the throats on my old mod 10. a 357 bullet pushes thru fairly easily. that same bullet at 357 pushes thru too easily for my blackhawk. i only shoot light 148 gr target loads sized 357 in my old S&W but ill shoot any and all in my ruger as long its 358.