Survey - Slugging of .38 S&W Bores

[Bigslug]

I'm in the process of acquiring a Webley MKIV chambered for this round, and have some curiousity.

One of the truths about the .38 S&W cartridge - a bazillion different handguns have been chambered for it by a quarter-bazillion different manufacturers.

While the nominal bullet diameter for the round seems to be .361", many of the guns chambered for it were made after the introduction of the .357" diameter .38 Special, and some companies were making both concurrently. A good example is the Victory Model Smiths made for the Brits in WWII. S&W made K-frames in both chamberings during the war - I'm curious if they (and other manufacturers) actually bothered with different barrel tooling.

So, regardless of make, what's the bore/groove diameter of your .38 S&W's; what slugs are you shooting through them; and how happy is the gun about it?

[rintinglen]

My victory model smith did indeed have a .360 bore. Which is why it is now a 2" 38 special with the original barrel residing in a parts bag somewher out in the shed, I never did get it to shoot worth a darn in its pre-conversion state.

[Bret4207]

Smith Perfected Model. Likes boolits of at least .361. Unfortunately, I don't have a mould casting that large.

[Guesser]

I have two S&W Regulation Police, 4" revolvers in 38 S&W. There is about 30 years difference in their respective ages, both shoot .360 cast soft 146 gr. boolits really well. I had some on hand and decided to try them before I slugged, as it happens, I never had to slug. The performance was far and above anything I expected.

[Bigslug]

Interesting responses thus far. I just got back from starting the paperwork on the Webley and came home with a box of Remington 146 grain LRNs to tide me over until I get dies and brass acquired. These are measuring out at .356" just in front of the case mouth.

Remington isn't currently using any bullet even close to this in any of their similar diameter rounds. If they were using the same slug for S&W's as well as Specials, it would make sense to start big and size down, but these appear to be 9mm's in an S&W case. I pulled one out of the bullets and it's a flat base - so no Minie-ball effect with this round.

Curious. . .

[Bigslug]

Well, I got the Webley home and slugged it with a Lyman 195 grainer. Got reduced from .358 down to about .355 in the process.

I was looking at the NOE 200 grain .364 mold, but it would seem there is no need. Now if only I could convince Lyman to make their 195 in something bigger than two cavities. . .

[MikeS]

Now that you know the size of the barrel, did you also slug the cylinder throats? If they're large, you're going to need a larger diameter boolit even with the .355 bore. At least that's the common thought about boolit size for revolvers, and I would imagine it holds true for the Webley as well.

[Bret4207]

Well, I got the Webley home and slugged it with a Lyman 195 grainer. Got reduced from .358 down to about .355 in the process.

I was looking at the NOE 200 grain .364 mold, but it would seem there is no need. Now if only I could convince Lyman to make their 195 in something bigger than two cavities. . .

I'm no Webley guru, but that sounds terribly tight. What are you measuring with, why did you start with a .358 boolit, what was it made of and did you get the bore completely free of fouling before you started? Did you feel any tight spots? If this gun is well used it may have a few thousandths of fouling caked to the walls of the barrel.

[Bigslug]

Yah. . .In retrospect, I think further experimenting may be needed. The .38 slugged a lot easier than my .455 Webley, which slugged down from an unsized .455 down to an even .450 with a fair amount of resistance. I think the .38 may have been getting most of its resistance from the lands and very little from the grooves.

I think I'll start a bullet from the back end and sandwich it between two dowels, squishing it out to ensure full bore specs.

[Bret4207]

Don't use dowels, find some brass rod or close fitting steel rod, anything you come across, but don't try to drive a slug with a dowel. Sooner or later it will upset and jam and them you'll have some real problems.

[MtGun44]

Please listen to Bret on the dowel, it can be a really serious problem.

My Colt PP slugs at .359", and wants bigger than .359 but I haven't yet found a mold
large enough.

Bill

[JeffinNZ]

I'm with Bret on the measurement. Sounds way too tight for war time British military tolerances - there's a good reason the Brits loaded cup/hollow base boolits. MikeS has a good point about cylinder throats also.

[Bigslug]

I'm with Bret on the measurement. Sounds way too tight for war time British military tolerances - there's a good reason the Brits loaded cup/hollow base boolits. MikeS has a good point about cylinder throats also.

I hear ya, but my puzzlement increases. A gun shop I frequent has an authentic full metal jacket .380/200 round in their possession, and I was able to measure the bullet at the case mouth a couple days ago. It's right there in that .355-.356" range. Mind you, I have heard it theorized that this particular bullet was SUPPOSED to be minimally stabilized to tumble on impact, but I don't think they'd have deliberately designed massive gas blow-by into the system.

Gonna have to put my curiosity off for a few days - all my beating, pounding, casting implements live under a different roof than I do.

[Bret4207]

.355 at the case mouth. What's the base mic? Tapered bullets are nothing new. You need some way to ensure the bullet sides are truly parallel to use the measurement as a judge that the whole bullet is that size.

[Hank10]

I have 3 .38 S&Ws. For what they're used for .358 bullets work fine and .38 special dies work fine with the .38 S&W cases. Cowboy action shooters who use these in their "pocket pistol matches usually load them this way. I've been shooting mine this way for at least 20 yrs.
Hank10

[badgeredd]

My Colt PP has a cylinder that checks .360" while the barrel slugs at .355". On advice from Bret and others, I cast soft lead to the .360" dimension. It works well and shoots very accurately.

Edd

[armed_partisan]

I have an old S&W .38 DA, 4th Change Top-Break with a 6" barrel in .38 S&W. It slugs .364-.365" . Planning on loading it with Makarov dies and .365" 95grn RN's from the local casting concern. Cheaper than buying a mold. Cartridge OAL has to be very short with these early top-breaks, too, like 1.210" or less, so I can't use any 200 grain molds that have popped up recently. This gun may be the exception, but it is one of the early guns by the original manufacturer in this caliber. Even the throats are .363" on the cylinder. .361" is undersized for this caliber for this gun.

[Bigslug]

Well, I got it slugged with a couple tighter fitting bullets and got .360"-361". Looks like the NOE folks knew what they were doing with a .364" mold that can be sized down a couple thou.

To "make brass" I did fire off a hundred of the undersized Remington 146 grainers. No drama - they didn't hit the target sideways - so there is some latitude. I will try my Lyman 195 grain round nose, but it looks like I'll be buying NOE's mold. FIVE CAVITIES!! OH THE HEADRUSH!