Bullet diameter in .38 special / .357 mag.

[Rossiter93]

Hello all,

Long time lurker here that had finally made an account.

I'm looking for some information regarding boolit diameter for .38 special and .357 magnum. Has anyone run the Lee 120gr TC boolit, powder coated, at .357" with any success? Someone offered me a Smith and Wesson 686 for a rifle I have, but I want to be sure I can load for it without having to buy another mold and sizing kit (money is tight right now, new house).

Thank you I'm advance.

[mdi]

To know for sure the gun's measurements should be known; throat diameter and groove diameter.
.357" will prolly work but how good?..

[tazman]

I have used that boolit without powder coating in a couple of my 38 special ans 357 mag revolvers. It shot well and loads from a speedloader really well.
I sized them at .357 and tumble lubed them instead of powder coated.
The particular revolvers I shot them in slugged at .357.

[Shiloh]

Mine are sized at .3584. The size they come out of my LEE push through sizer. My Lyman .358 die is about .3583 IIRC.
They all shoot well.

My TL LEE .358 SWC drops small and doesn't shoot for beans for me.

Shiloh

[slide]

I size all of mine at .358. This seems to work the best for me.

[Larry Gibson]

I have used that boolit without powder coating in a couple of my 38 special ans 357 mag revolvers. It shot well and loads from a speedloader really well.
I sized them at .357 and tumble lubed them instead of powder coated.
The particular revolvers I shot them in slugged at .357.

Same here except I lube and sized in Lyman 450. The 120 TCs shot well in 38 SPL and 357 mag in revolvers ad rifles.

[bstone5]

Cast several different weight bullets for 38 Special. I powder coat and install a home made gas check. My wife and her sister shoot the 38 Special a lot. I use a 125 grain powder coated bullet with the home made gas check and load with 4 grains of Trail Boss. The two girls go thru a lot of rounds when we go to the gun club.

[waco]

Size them to a snug slip fit in the cylinder throats. You should be able to push them through the cylinder with the erases of a pencil with just a bit of resistance.

[jeepyj]

I'd Try to see if you can achieve .358. In one of my revolvers I had it keyhole with .357. BTW Welcome aboard!

[gpidaho]

Welcome along. Size the bullets to the size of the largest cylinder throat. Like Waco said, you should be able to push the bullets through the cylinder throat with some resistance. Gp

[Rcmaveric]

For 9mm, .357 Mag and 380 ACp i size them all to .357. I do use different molds though. I am certain i could use the same bullet for various calibers though.

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[Hick]

I had thought of trying 0.357, but the only sizing die I had was .358. After about 3000 rounds with no leading I decided to stop looking for a .357 sizing die. My two revolvers and my lever apparently prefer .358

[Petrol & Powder]

All good input above.
The diameter of the bullet will likely be determined by the diameter of the cylinder throats. If the throats are .357" then the bullet will not be larger than .357" when it reaches the barrel. If the throats are smaller than the groove diameter of the barrel, the throats will become the de facto last "sizing die" the bullet passes through before reaching the barrel.

[Rcmaveric]

I used the .358 tilll i got my .357 Mag. It wanted a .357 bullet so switched to that and all the other guns liked it also. I admit to be lazing and was curious.

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[gwpercle]

I've been working with that bullet a lot. Lee 356-120-TC from a double cavity mould drops .3575, when cast 50-50 COWW - lead +1% tin, sized .357 in a Lyman 450 with Lithi-Bee lubricant.
They are extremely accurate in both 38 special and light-mid range 357 magnum loads.
The accuracy surprised me and Tazman also noticed this in his loads, handgun and I think rifle also .
I use the 9mm Luger taper crimp die to taper crimp in 38/357 and it works like a charm...no bullet creep.
I purchased a 124 gr TC mould from NOE and had it cut for a Gas Check . With this gas checked TC boolit I can load hotter loads for magnum and have no leading problems @ higher velocities.
I still shoot a lot of the Lee plain based boolit @ 38 special velocities because it is very accurate with several different powders....just about every powder I have tried worked well.
Gary

[gpidaho]

As mentioned above, the cylinder throats will size the bullet to what ever size the throat happens to be. Sizing the bullets to more than half a thousandth or so more than this measurement just causes extra wear and tear on the weapon. Gp

[Char-Gar]

If you are wanting high end accuracy, match the bullet size to your cylinder throat size. In a Smith and Wesson that will generally be .357 size bullet. In an older Colt, it generally be a .359 bullet. You can split the difference and get good results, if not the best with .358.

I don't know about others makes as I don't have any.

[Cherokee]

I size to .358 for all three of my 686's, but have never used the Lee bullet in them. That is my go-to 9mm bullet @ .357. Cyl throat size should be your guide.

[Texas by God]

When I size I use .358", but I shoot a Lee 105 swc and Lee 150 swc in two S&W's with no sizing- just LLA and shoot- accurately. I haven't miked them because I don't care lol.

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