.357 or .358 for .38 Special?

[FergusonTO35]

Hey folks, currently having lots of fun with my .38's and just ordered a Lee 358-148-WC so thought I would ask about sizing. For a few years now I've been sizing my .38 Special boolits to .357 as I also use this size in 9mm so it keeps everything simple and some boolits can be used in both calibers. They shoot just fine with no leading. I know that historically .358 has been used for the .38 Special, perhaps more due to widely varying bores than anything else. Would there be any real advantage to switching to .358? What do you guys typically size them to? My guns include S&W 10-5, 10-10, 637, and a Ruger Service Six. For the Marlin 1894 I use a .360 die which doesn't really size them at all, just squirts lube into the grooves. Everything gets Randy Rat's Tac-X at my house, it's some darn good stuff!

[Virginia John]

I use .358 for everything including 9mm. This seems to work good in all my guns.

[Pine Baron]

Hi Ferguson,
I Powder coat and size to .358 (Lee sizer). I shoot these in my 9's, Walther CCP, Helwan Cadet (Beretta M1951 Brigadier clone) and Hi Point 995TS (which probably would shoot a hand full of gravel). My .357/38 Taurus 605 and S&W Airweight. It really comes down to what each individual weapon will tolerate. Of course YMMV.

[flyingrhino]

If you don't get leading with .357 then I see no need to change. If it was undersized you'd know it. Mine are sized to .358 because that's the sizing die I bought when I started loading for 357/38 spl.

[tazman]

I have several 38/357 revolvers and they all currently get .358. That said, the cylinder throats vary somewhat on the different guns. I have cylinders that measure .356, .357, and .358. Luckily the ones with the smaller throats have smaller bores to match.
Rather than make up different sizes for each specific gun, I have been shooting them all with .358 boolits.
I could get slightly better accuracy making up different sizes for each gun, but I have found that by using certain boolit styles, the accuracy is pretty much the same for all the guns. With the smaller throats, I use either round nose, round-flat, or wide flat nose designs. This keeps the boolit lined up with the throat better during transition. If I use a boolit with a sharp shoulder(wadcutters and semi-wadcutters) in the smaller throats, the shoulder gets deformed during the transition and I get fliers. If I sized them down to throat size, I suspect they would work fine. I am too lazy to do that.
In your case, with .357 working well with no leading, I would continue to use that size in your gun. If you wish to experiment, the Lee push through sizers are certainly a cheap way to experiment.

[str8wal]

If it works, why fix what ain't broke......

[Char-Gar]

The truth of the matter is that it doesn't make a difference if you size .357 or .357. In Smith and Wesson sixguns .357 might give a smidge better accuracy, but unless you are a bench rest shooter of sixguns, you won't know the difference. If you had to choose one, .358 might have a little more utility in a larger variety of sixguns, but in all reality this is just a distinction without a difference for 99.99% of the people shooting these sixgun. Worry about how you grip the revolver, sight picture, trigger and breath control and don't sweat this kind of mostly theoretical stuff.

[376Steyr]

For another data point, I size to .359". Downside is loads with some thick-walled cases, like GI 38 brass, are difficult to chamber. Plus some of my 9mm's refuse to chamber a .359".

[drifterdon]

I size to .358. .001 over the jacketed .357 bullets I load.
Has worked well so far.

[sixshot]

Char-Gar nailed it!

Dick

[Lead Fred]

My mould drops .360, they all get sized to .358

[Petrol & Powder]

I agree, Char-Gar hit the nail on the head.

.358" works in a large number of 38/357 revolvers.

9mm pistols drive me crazy with their bore diameters all over the map. My S&W and Ruger 38/357 revolvers are just the opposite, they are amazingly consistent and all work just fine with .358" bullets. I've heard people claim slight improvements with .357" bullets in some 38 Special S&W's but I agree with Char-Gar, you'd have to be an incredibly good shot to see the difference.

Colt's may be the exception. I think the bores may run a bit tighter in some Colt revolvers but I don't have enough experience with them to give a strong opinion. I sold off most of my Colts when they became more valuable to others than to me.

[dragon813gt]

I size mine to .359 because they get used in a Marlin as well. I don't load different batches just for the Marlin. I will size smaller for use in a 9mm.

[dtknowles]

.357 worked for me but got to reading and decided I should try .358. I did not see a difference but I stayed with .358 anyway. I size my 9mm to .355, I want them to plunk and I don't seem to get leading.

Tim

[FergusonTO35]

Thanks for all the info. I was shooting some Lee 358-148-WC sized to .357 out of my little 637 today and the groups were as tight as they have ever been. I'm wondering if .358 might give more consistent chronograph numbers. With a snub .38, out of a ten shot string all except one or two are within 20 fps of each other. The one outlier skews the average up or down.

[Char-Gar]

Thanks for all the info. I was shooting some Lee 358-148-WC sized to .357 out of my little 637 today and the groups were as tight as they have ever been. I'm wondering if .358 might give more consistent chronograph numbers. With a snub .38, out of a ten shot string all except one or two are within 20 fps of each other. The one outlier skews the average up or down.

I fear you are a hopeless case! Take the batteries out of that machine, so they won't corrode and kill the chrony when you want to sell it. All that matters is how well the bullets play follow the leader to the target.

[FergusonTO35]

Too late....

[FergusonTO35]

.358 did the trick. I tried the same 2.8 grains Bullseye and Federal primer in the 637 today, here are the results:

Low: 651.7
High: 679.3
Average: 661.6
Ex. Spread: 27.65
St. Deviation: 10.29
Energy: 143.83

Gonna try Winchester primers next.

[tazman]

Those are excellent results.

[lotech]

Generally, I agree with what's been mentioned, but if you do a lot of shooting and experimentation, you'll find a noticeable accuracy difference with various revolvers when comparing .357" vs. .358" bullets. I've found some Colt and (fewer) S&W revolvers do better with .357" (maybe even .356") bullets, but this can become a hairsplitting exercise. If you have several .38 or .357 revolvers, it's far easier to size all bullets to .358" as a .358" bullet will usually provide decent accuracy in everything.