Reloading .38 S&W

S&W .38 Double-action 2nd Model, made around 1884- the 2015 present from my wife that started it all.

This post contains load data. All load data should be used with due caution. It is common practice to start 10% below the listed load and work up, insuring that everything remains safe at each step. The simple rule of thumb is, ‘When in doubt don’t. This is especially true when loading for antique firearms. All antique firearms should be examined by a competent gunsmith prior to firing to insure that they are safe. The reader employs the reloading data contained in this article at their own risk; the author assumes no liability for the use or misuse of this information.

In 2015 Linda bought me a S&W .38 Double Action and I fell in love with these top-break revolvers, particularly the Safety Hammerless model. These guns chamber the old .38 S&W cartridge, and this is a problem; the only ammo available in factory loadings these days are round nose lead, usually 145-147gr. loaded over an anemic powder charge designed to not blow up the worst revolver ever made. This is OK if all you intend to do is poke holes in paper… and are rich. Like most obsolete/ limited production cartridges they are expensive. I’m not rich, so it was obvious I was going to need to reload if I wanted to do any serious shooting in these old guns.

S&W .38 Safety Hammerless 4th Model with a bobbed barrel, new front sight and Desert Ironwood grips.

Black Powder or Smokeless?

The conventional wisdom is that these revolvers should only be fired with Black Powder or a substitute like Pyrodex. This is a pretty simple proposition; fill the case 3/4 of the way with black powder and stuff a bullet on top of it. As long as you make sure there is some compression of the powder you’ll be alright.

The original cartridges used balloon-head cases, which were weaker but they held more powder. In a modern case you probably cannot stuff enough FFg of FFFg black powder in it to blow anything up or even significantly damage a gun that is in fireable condition, as long as you don’t leave an air-gap between the bullet and powder. Using Black Powder commonly thought to be the safest route for loading for these old guns, though it has it’s own issues. If you want to err on the side of caution you could do worse than going this route, just remember to clean your gun religiously right after each shooting session.

I didn’t go down this path. When smokeless ammunition became available every gun was a ‘Black Powder’ gun, and the loads were tailored to take that into account. I have never seen any evidence that smokeless loads are inherently unsafe in these weapons, but nonetheless it is best to approach loading for any antique with caution. When I started reloading a friend had sent me several bottles of Unique, and as this is one of the first commercially available smokeless powders for pistols I figured it was a good place to start.

So, let’s get on with it, shall we?

Reloading .38 S&W is not without issues, starting with the fact that while modern .38s use a .357 bullet this cartridge uses a .361 caliber bullet, and these are not commonly available. There are some people casting round-nose lead bullets for these, but they are a fair bit more expensive than more common bullets.

Antique guns vary; some have tighter or looser bores. Some people have had luck with soft lead .357 bullets ‘bumping up’ the extra .004″ in these guns. I slugged my guns and all three of my S&Ws came out at exactly .361- good quality control for 19th- early 20th century guns! I decided to go with the conventional wisdom for using modern bullets, which is to use a 148gr. .357 Hollow-Base Wadcutter (HBWC.) These are pretty soft and the hollow base of the bullet reliably expands to bore diameter, even with relatively light loads.

Hornady 148gr. HBWC

Reloading data for this cartridge is not terribly common; after a brief search I discovered , the reloading pages of M.D.Smith, who lists a number of loads. Importantly he specifies which loads are safe for top-break revolvers like my S&Ws. He does not specifically list the 148gr. HBWC, but using the data for the .145gr. RNL works alright.

Smith lists a maximum load of 2.8gr. for these heavy bullets in top-break revolvers, but you want to approach this figure with due caution, and bear in mind the quality of the gun you are shooting it in. A load that might be fine for a S&W or Iver Johnson might break the rather fragile lock on an H&R. Go on then, ask me how I know…

.38 S&W is a short casing, so you don’t fully seat the wadcutter as you would in .38 Special. I found that leaving about .200″ protruding from the case worked well. Eventually I settled on a load of 2.7gr. of Unique, and this became the go-to load for the first thousand rounds I put through my guns.

Hornady 148gr. LSWCs loaded in .38 S&W

Mind you, success was not instant and total. I was reloading on .38 Special dies, and while these can be adjusted to work it’s far from ideal. The seating die will squeeze the bullet enough to hold it in place even under recoil, but I was spewing a lot of unburned powder and power levels were low. Standard paper targets were tearing as often as the were getting clean holes, which indicates very low velocity.

I solved the incomplete ignition problem by shortening a .38 Special seating die so I could properly crimp the shells. The improvement was immediate and dramatic. No more unburned powder, a more authoritative crack! at the muzzle and a significant increase in recoil (though it remains mild.) No more torn bullet-holes in targets either. After some experimentation I determined that a moderate amount of crimp worked best. You’ll need to experiment with this yourself to find what works for you.

Now, I can’t tell you what sort of velocity you will get from this load; I only just got a chronograph. I can tell you that testing on kiln-dried 1-3/4″ thick Douglas Fir penetration was comparable to .380 hardball from a short-barrelled gun. I call that a success!

The 148gr. HBWC over 2.5gr. of Unique punched a cookie-cutter hole in a free-standing 1-3/4″ douglas fir and fully embedded the bullet in the free-standing plank behind it. This penetration was approximately the same as .380 ACP hardball fired from a short-barrelled pistol.

Use the Right Dies!

While you can use modified .38 Special dies to reload .38 S&W it’s not the ideal solution. The main issues were I had to shorten a die to crimp the cartridges properly. the other problem is brass life. The difference in diameter between .38 Special and .38 S&W is only four thousandths of an inch, but it actually makes a difference. The brass gets worked harder in both resizing and expansion in the chamber, and in my experience this has resulted in cases cracking prematurely; sometimes in as little as three loadings. In this low-pressure of a round it ought to last quite a bit longer than that. using the correct dies has eliminated that problem.

Other Loads

Perusing the shelves at Pinto’s Guns I discovered some .360 150gr. LSWCs. They often make estate purchases, and Lord only knows where these came from. Perhaps someone cast them at home, I don’t know. They proved to perform well loaded over the same 2.7gr. of unique as the HBWCs. Eventually I ran through their supply and was on the lookout once again.

I tried 158gr .357 soft-lead SWCs and they worked well enough over 2.5gr. of Unique, but I wondered if I might not do better. I thought a lighter bullet might perform well, but .361 bullets are rare, and if you want them to weigh less that 145gr. they are practically unobtanium… but there’s more than one way to de-fur a domestic feline.

Home-built bullet-swaging set-up; high-tech it ain’t.

I got a .361″ reamer and reamed a hole in a block of mild steel, then made a .361″ punch with a concavity in the nose, using a drill-bit and some grinding stones in a Dremel-tool. Drop in a .357 bullet, insert the punch and hammer it down and voila! .361 LSWC. I’ve taken to using 125gr TCL bullets from Aardvark Enterprises, and loaded over 2.5gr. of Unique or 2.0gr. of Red Dot the results have been very good. I’ve even swaged .355 115 gr. FMC rounds, which have also performed well with 2.0 gr. of Red Dot.

Swaged 125gr. LSWC on the left, 115gr. FMCSWCs on the right.

These have proven to be great loads for punching paper out to 25 yards. Velocity? No idea, but they punch clean holes in the paper and shoot to point of aim. Now that I have a chronograph I’ll be testing these loads, factory ammo and a few others besides. I’ll be using a 3-1/4″- barrelled Iver Johnson and my 1-5/8″ barrelled S&W, and I’ll provide the data when it’s available.

I’ll also be Gel-testing them, but that will need to wait; The Clear Ballistics Gel is not inexpensive to set up initially!

Again, I caution you to use this load data carefully, and only in revolvers that have been thoroughly checked to insure that they are safe to shoot.

Stay tuned…

Michael Tinker Pearce, 13 November 2019


3 thoughts on “Reloading .38 S&W

  1. Kris

    This was interesting. My youngest reloads for almost everything he owns (I think) and it was nice to see what he’s always talking about! He’s a gunsmithing encyclopedia..I’m not just saying that cuz I’m the mom! lol


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