.357 Magnum Load Data

The editor recently pointed out that my columns have been heavily biased toward loading rifle ammo. Taking the hint, I offered to remedy the deficiency by putting together some handloads for the ever-popular .357 Magnum. I suggested that I take a good look at the recently released Lyman, Nosler, and Barnes reloading manuals for the latest recipes with the newest components. He concurred, and the exercise afforded me the opportunity to revisit some of my favorite .357 handloads that I developed during the 35-plus years that I've been loading the cartridge.

For those who don't know, Smith & Wesson and Winchester co-developed the .357 Magnum revolver/cartridge package about 75 years ago. It was the first handgun round tagged with the "magnum" moniker. Prior to the .357, the old .45 Colt charged with up to 40 grains of blackpowder held the distinction as the "most powerful" handgun cartridge. Phil Sharpe and Elmer Keith contributed to the .357's development, and they experimented with S&W's .38-44 High Velocity cartridge, suggesting that its performance could be improved upon.

However, S&W decided not to simply introduce a further hopped-up .38 Magnum. Instead, the company redesigned and significantly improved the strength of the large-frame .38-44 Outdoorsman target model revolver to accommodate the nearly double chamber pressure generated by the .357 Magnum. S&W also increased the case length by 1/8 inch to prevent anyone from loading the then-new cartridge in either regular or heavy-duty .38 Special revolvers. Original .357 Magnum specs touted the muzzle velocity for a 158-grain, lead SWC bullet of more than 1,500 fps from an 8⅜-inch barrel. Since its introduction, the .357's ballistics have gradually diminished. Current factory ammo delivers substantially less performance, i.e., velocities are 150 to 200 fps lower.

Soon after my wife and I married, I purchased a .357 Magnum Ruger Blackhawk single-action. I reloaded using an RCBS single-stage press and die set with a steel sizer. Our budget would barely allow me to load a box or two of ammo occasionally. We met another newlywed couple, and I convinced Rod he needed a handgun to go shooting with me. He opted for one of the then-new Thompson/Center Contender single-shots fitted with a 10-inch barrel chambered in .357 Magnum. My shooting situation improved when we struck a deal where he bought the components; I provided the tooling, time, and effort to reload the empties; and we shared the ammo 50/50.

Since then, I've bought, sold, and traded lots of guns, and I no longer own my first Blackhawk. However, I still have several .357 handguns on hand, including a New Model Ruger Bisley single-action revolver. It seemed the most appropriate test bed for this review, especially since I had a machine rest set up for it. For serious handgun load development, I now depend on a machine rest simply because my arms are too short to hold a handgun far enough away to allow my eyes to clearly focus on the sights and target at the same time.

Because the .357 Magnum is actually the same caliber as the popular .38 Special, a huge selection of suitable bullets--both jacketed and cast--are readily available. Bullet weights typically range from 110 to 180 grains, and different nose shapes and types of bullet construction abound. Reviewing the latest editions of the reloading manuals noted earlier, I selected several component options suitable for .357 Magnum handloads.

The Ruger Bisley has a 7.5-inch barrel, so I expected to obtain top performance from the test loads. But first I had to prepare them. Checking my inventory, I had everything I needed except Ramshot Enforcer. According to the Barnes and Lyman manuals, Enforcer seemed to be a promising propellant to launch the heavier slugs. I also used different brands of Small Pistol Magnum primers and brass to duplicate the recommended recipes as closely as possible.

.357 Mag Case Prepping

This first step is probably the most important, especially for magnum handgun cartridges. The .357's maximum average pressure is specified at 35,000 psi. The relatively thin-walled cartridge cases must remain intact when a round is fired. I tumble them before loading so that I can easily inspect and weed out any cracked or otherwise damaged brass. You should also make sure there's no debris or other obstruction lodged inside the case.

Lubing handgun brass and resizing it with a steel sizer die is a not-so-pleasant memory of my past reloading experiences. For several years now, thankfully, we have carbide dies to resize most straight-walled revolver and tapered pistol brass. The super slick, hard insert eliminates the mess and bother of applying and removing the lube required to prevent a case from seizing in the old steel sizer die.

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I always clean the primer pockets--in fact, I actually use an RCBS Case Prep powered unit to both clean and uniform the pockets each time I prepare a batch of brass. Then, I usually trim each one to a uniform length and deburr the case mouths--even if none of them are too long. Why? Because applying a uniform bullet crimp helps ensure consistent ignition. That, in turn, can make my handloads more reliable and deliver better performance.

.357 Mag Priming

After the dirty work is finished, you should wash up to remove any grit and grime from your hands. However, hospital-style sterile conditions are not required when priming. A friend of mine dons thin cotton gloves and carefully handles each primer with a pair of tweezers. I, on the other hand, dump the quantity needed into a primer tray, pick one up with my bare--but clean--fingers, place it in the priming tool I'm using, and firmly seat it just below flush.

If I'm loading more than just a few rounds, I use one of several priming tools available with an attached primer magazine. Either way works for me. Just use common sense to avoid potential contaminants when handling primers and always wear protective glasses.

.357 Mag Case Mouth Flaring

You must expand or flare the case mouth to facilitate bulletseating. The reason this operation wasn't included in the case-prep section above is simple: I don't usually do this until I revisit and finalize the bullet selection. The heel may be sharp or rounded or even tapered, i.e., like a boattail rifle bullet.

You should carefully adjust the expander plug position to expand the mouth just enough--but not too much--so the bullet is fully engaged and aligned with the case mouth prior to seating. Too little, and the case may score the bullet as it's inserted. This is especially true when loading cast bullets with or without gaschecks. Lead and lube will be scraped up the circumference of the bullet as it's seated and fill the crimping groove. This may interfere with crimping the bullet properly or even cause the case mouth to buckle.

Favorite .357 Magnum Handloads
Bullet	Powder Type	Powder Grs.	Case	Primer	Velocity (fps)	Extreme Spread (fps)	Standard Deviation (fps)	25-Yard Accuracy (in.)
Case Bullets
Clements 155-gr. SWC	H240*	13.5	R-P	CCI 550	1479	64	16	2.40
Vaiant 160-gr. SWC	Blue Dot	9.5	Fed.	WSPM	1320	87	27	3.00
Cast Performance 180-gr. WFN-GC	Enforcer	11.7	Win.	WSPM	1178	49	13	2.00
Cast Performance 180-gr. WFN-GC	H110	13.5	Front.	WSPM	1205	51	13	1.70
Jacketed Bullets
Barnes 125-gr. XPB	Enforcer	16.5	Win.	WSPM	1578	49	12	1.90
Hornady 125-gr. JHP-XTP	Power Pistol	10.0	Speer	CCI 550	1448	71	20	3.00
Hornady 125-gr. JHP-XTP	VV N110	16.5	Speer	CCI 550	1520	75	26	1.90
Barnes 140-gr. XPB	AA No.9	12.5	Win.	WSPM	1330	92	27	2.00
Hornady 140-gr. JHP-XTB	AA No.9	13.5	Win.	Rem. 5 1/2	1368	65	25	2.50
Hornady 140-gr. JHP-XTB	H110	18.4	Front.	WSPM	1479	138	41	1.80
Hornady 140-gr. JHP-XTB	H110	19.0	Fed.	Fed. 200	1406	106	32	2.20
Speer 146-gr. JSWC-HP	Unique	8.1	Speer	CCI 550	1322	71	18	2.00
Sierra 150-gr. JHC	W296	17.0	IMI	Fed. 200	1311	88	26	1.90
Nosler 158-gr. JHP	H110	15.8	Fed.	WSPM	1251	116	30	2.20
Sierra 158-gr. JSP	2400	14.6	R-P	Fed. 200	1306	87	25	2.90
Sierra 158-gr. JSP	H110	14.0	R-P	CCI 550	1160	42	17	2.50
Speer 158-gr. Gold Dot	Unique	81	R-P	CCI 550	1210	75	20	2.40
Speer 158-gr. Gold Dot	VV N110	14.5	Fed.	Fed. 200	1250	72	23	2.20
Speer 158-gr. Gold Dot	VV N110	15.0	Fed.	Fed. 200	1261	69	22	2.40
Winchester 158-gr HP	AA No.9	14.6	R-P	CCI 550	1393	69	18	2.20
Hornady 180-gr. JHP-XTP	AA No.9	13.0	Norma	Fed. 200	1188	80	25	2.10
Hornady 180-gr. JHP-XTP	W296	13.0	R-P	Fed. 200	1089	83	22	2.40
Nosler 180-gr. Partition HG	2400	12.5	Fed.	Fed. 200	1221	92	23	1.40
Nosler 180-gr. Partition HG	W296	12.5	Fed.	WSPM	1022	72	23	1.90
* Handgun H240 in long obsolete.

.357 Mag Powder Charging

I typically use a volumetric measure to dispense powder charges after I've calibrated it by weighing several charges on an electronic scale. Propellants like H110, Accurate No. 9, and Enforcer flow like water, so charge weights vary only 1/10 grain at most. Blue Dot, Unique, or other flake-type propellants are not as compatible with volumetric measures, so thrown charges can vary up to 1/2 grain. That's a lot if you're loading 15 grains or less of propellant. Never use these for maximum loads unless you weigh each powder charge. For non-maximum charges, I typically weigh every tenth charge, but I always visually inspect each case in the loading tray to make sure I've properly charged each one before seating the bullets.

.357 Mag Bulletseating

Most seater dies, if properly adjusted, will both seat and crimp the bullet. Place a sized and trimmed case in the shellholder, raise the ram, and screw the die in until it touches the case mouth. Then back off the die a half-turn, replace the empty case with one that's flared and charged, and position the bullet squarely on the case mouth. Guide the case/bullet combo into the seater die with your fingers, and incrementally raise and lower the ram while adjusting the seating stem position as needed so the top of the cannelure or crimping groove is almost aligned with the case mouth. Be sure to use a seating stem that closely matches the nose shape to avoid damaging the bullet.

When the bullet is seated deep enough, back up the seating stem several turns. Screw the die in incrementally--a quarter-turn at a time--until you achieve the desired crimp with the ram in the full-up position. Screw the seating stem down until it firmly engages the bullet nose and tighten both jam nuts on the die body and stem. Remove that round and seat another bullet carefully to verify that the die and seating stem are properly adjusted to seat the bullet and crimp the case mouth correctly.

You may have to tweak one or both slightly to achieve the correct seating depth and amount of crimp. Remember, you can always seat the bullet a little deeper and crimp the case mouth a little more, but you'll surely damage the case and/or the bullet if you seat it too deeply or force the round into the die too far.

.357 Mag Loading & Shooting

Like I said, I revisited some of my old favorite .357 handloads. When I checked my stash of ammo, I found several boxes dated as far back as the mid-1980s. I assembled several fresh batches using proven propellants like H110, 2400, W296, AA No. 9, and Unique. I also experimented with some newer propellants, including Ramshot Enforcer and VihtaVouri N110.

As you can see in the chart on page 19, I eventually tested quite a few different .357 Mag. recipes. When I started this project, I figured I'd load four or five boxes of handloads to complement the ones I had on hand. However, the more I loaded and shot, the more I wanted to load and shoot. I eventually fired 925 rounds at 150-plus targets. I guess I was just having too much fun loading and shooting. And as it turned out, I found some new favorite loads for my trusty .357.