358 Winchester Load Data

Modifying a cartridge case to another shape and/or caliber has been the pastime of wildcatters seemingly forever. Most of these creations end up on the scrapheap of history, but those that exhibit excellence become popular, and if they’re lucky, they are transformed into “new” factory rounds by one of the major ammunition companies. One of the best of the “lucky” bunch is the .358 Winchester. It has had an interesting and uncomplicated developmental history that incorporates the principle of parsimony, usually paraphrased as Occam’s razor, i.e., the simplest solution is usually the best solution.

The U.S. Army adopted a new .30-caliber cartridge as its service round in 1954 to replace the good old .30-06 Springfield. However, the Army brass was astute enough to see that the new round duplicated the decades-long effectiveness of the ’06. It was called the 7.62x51mm NATO. The new round was essentially a slightly shortened .30-06 case that fired a 150-grain bullet at a nominal velocity of about 2,750 fps.

Ever on top of things, Winchester saw the potential of the 7.62x51 and introduced it to civilians as the .308 Winchester in 1952, two years before the military’s adoption of the 7.62x51. The shooting public was at first reluctant to accept this new .30-caliber round, but as its accuracy and versatility became known, resistance faded. Soon wildcatters were necking the case up and down to other calibers, producing many offspring. For example, P.O. Ackley reported on “.270/.308” and “7mm/.308” versions as early as 1962.

Several new commercial rounds based on the .308 Win. also came into being, most notably the .243 Winchester (1955), the .260 Remington (1997), the 7mm-08 Remington (1980), and the .338 Federal (2005). Interestingly, to my knowledge, there was not a .25-caliber version of the .308 Win., as the existing .250 Savage and .257 Roberts, fine cartridges in their own right, had that niche covered. And we also have the .358 Winchester, introduced in 1955. It followed on the heels of another big-bore lever gun.

In 1936 Winchester had introduced the .348 Winchester in the big lever-action Model 71. The Model 71 lasted until 1958 and was replaced with the Model 88, a spiffy lever-action with a one-piece walnut stock, a detachable box magazine that allowed the use of Spitzer bullets, and arguably the worst trigger ever put on a sporting rifle. The Model 88 was chambered for short cartridges like the .308 Win., .243 Win., .284 Win., and .358 Win.

In addition, bolt actions like the Winchester Model 70, Ruger Model 77, and Ruger American have been chambered for the .358 Win., as have several lever actions, such as the Savage Model 99, Browning’s version of the Model 71, and the Browning BLR.

Speaking of .358 Win. rifles, over the years I have had four different rifles chambered for the cartridge and have accumulated considerable reloading data on them.

In 1975 Ruger made a run of Model 77s in .358 Win., and I traded for a used one at a gun show. It shot so-so, and I never took a single head of game with it. I sold it in 2003. The next one I owned was a brand-new Browning BLR made in 2015, but it was a disappointment in the accuracy department, and the trigger was, well, not good. I quickly got rid of it.

I went without a .358 Win. rifle for a while—a disastrous development—but then I traded for another Ruger Model 77 in .308 Win. and converted it to .358 Win. by having it rebarreled with a 23.6-inch, straight-taper tube with a 1:13.5-inch twist rate. It shoots just fine, and I plugged a nice buck with it a couple years ago. I used a handload with the Nosler 225-grain Partition. Maybe that bullet was a bit heavy for a 200-pound deer, but I can’t argue with its success.

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The last .358 Win. rifle of my acquaintance was a Ruger American Predator that was introduced in 2019. It was a “test rifle,” so it went back to Ruger. But if I hadn’t already had a good .358 Win., it would have stayed with me. For anyone who pines for a good-quality .358 Win. rifle that won’t break the bank, the American is certainly one to consider.

Making Some Ammo

Factory-loaded .358 Win. ammo is still listed by Winchester as “seasonably available,” but finding these loads is usually a treasure hunt. So handloading is the way to go.

The usual preliminary handloading procedures are well known to seasoned reloaders, so I’ll be brief here. After inspecting fired cases for splits or other flaws, resizing should be done carefully to avoid setting the small shoulder back too much—this invites incipient case head separation. Trim length is 2.005 inches. The maximum average pressure (MAP) for the .358 Win. is 52,000 CUP (copper units of pressure), the same as for the .308 Win.

When it comes to components, handloaders have an excellent selection of bullets that work wonderfully in the.358 Win. New cases are usually available from Winchester, Hornady, and Starline. And in a pinch, one can always neck up .308 Win. cases. In fact, I used some necked-up cases for a few of the test loads listed in the accompanying chart. You just need to check their weights against .358 Win. cases as an indicator of internal volume, as this can vary considerably from brand to brand.

Given the .358 Win.’s modest powder capacity, standard Large Rifle primers are suitable for handloads. Powder selection is uncomplicated, as there are many medium-burning rate propellants that work great. A long list could be prepared, but Benchmark, CFE 223, H4895, Varget, and TAC should cover all the bases.

Bullet choices depend on the shooting chore, but a couple of categories can be quickly identified. The Speer 180-grain and 220-grain Hot-Cor FN bullets are designed for rifles with tubular magazines, as their cannelures are positioned for proper cartridge length for lever guns for trouble-free functioning. And both are perfectly suitable for bolt guns, too. For deer-size game at modest ranges, the 180-grain version is hard to beat, and the 220-grain bullet is perfect for larger game. Velocities with the 180-grain bullet top 2,600 fps, and the 220-grainer travels around 2,450 fps with the right load. Additional good bullets for close-range deer are the 200-grain roundnoses from Hornady and Sierra.

Hornady makes two 200-grain .35-caliber “pointed” bullets: the Spirepoint and the FTX that offer a different perspective on “short, fat bullet” ballistics, which I’ll discuss a little later.

For heavier game, the 225-grain bullets are appropriate. The Spitzer Boattail (SBT) from Sierra is accurate and can be launched at about 2,500 fps with several propellants.

Whatever the caliber or game, one can never go wrong with the reliable Nosler Partition bullet. Two weights are available in .35 caliber: 225 grains and 250 grains. The 225-grain version’s cruising speed is around 2,500 fps. My experience with this bullet is limited to a nice 8-point whitetail. As expected, the bullet behind the shoulder zipped right on through, and the deer gave up the ghost after running about 50 yards.

The 250-grain bullet would be a mainstay for elk, moose, and other large ungulates, as long as they’re not out of the round’s range, as this fine bullet is a mite too heavy for top velocities from the .358 Win. A speed of about 2,350 fps is about all the round can deliver, but the penetration and controlled expansion of this heavy Partition are legendary.

Other options for the .358 Win. are the excellent lead-free bullets like the Barnes 180-grain TTSX and 200-grain TSX. Both penetrate like the dickens and retain almost all of their original weight. In my handloads, velocities were in the range of other bullets of these weights, and their accuracy was slightly above the overall average for the Ruger American rifle.

For the heaviest game, the 250-grain bullets from Hornady, Nosler, and Speer pack a real punch. Again, just keep the ranges reasonable. These bullets have ballistic coefficients (BC) of .375, .446, and .422 respectively, and as bullet weight goes up, so does the downrange energy.

For an “all-round load,” I recommend the Nosler 225-grain Partition over a dose of 49.0 grains of TAC, 50.0 grains of CFE 223, or 46.0 grains of IMR 3031. Out of my rebarreled Ruger Model 77, velocity of the TAC load was 2,497 fps, and while it’s not the most accurate of my handloads, its performance on the deer I plugged with it was excellent.

Some loading manuals list data for .38-caliber pistol bullets in the .358 Win., but in my experience their usefulness is quite limited. They are touted as suitable for plinking, dispatching varmints up close, and other mundane chores. But due to their length, the feeding of pistol bullets in lever-action or bolt-action rifles is problematic, and their thin jackets make them virtually bombs on targets.

Test Load Results

Now let’s look at some of the handloads I brewed. My usual protocol was followed, with a minor exception. All loads were fired from a Caldwell DFT Lead Sled from inside my shooting building except for the ones fired in my original Ruger Model 77. I tested it outdoors and sold it before I built my indoor facility.

Three, five-shot groups were fired with each load at 100 yards, and the accuracy listed is the average of those three groups. Velocity is for five rounds measured with an Oehler Model 35P chronograph with the Skyscreens spaced four feet apart and the midpoint positioned 10 feet from the guns’ muzzles. The rifles’ bores were cleaned after every 15 rounds, and one fouler round was fired before shooting for record.

In a nutshell, the Ruger American rifle and the custom Ruger Model 77 averaged a smidgen over an inch, while the group average of the original Model 77 and the Browning BLR were about twice that. There were no ballistic “surprises,” and collectively the handloads were very well behaved.

Looking at the load results as fired in the rebarreled Model 77, these loads stick to the basic premise of the .358 Win. in that they launch large-diameter, moderately heavy bullets at medium velocities. They are designed for shooting big game at sensible ranges, and for that task they excel.

Even though blunt ogives are totally out of fashion these days, the Speer FN bullets are exquisitely designed for their intended role and performed superbly. That said, the trajectory of roundnose and flatnose bullets has been a topic of discussion for decades, and in an effort to improve trajectories, Hornady introduced the FTX line of bullets that feature soft polymer tips that make these pointed bullets safe in tubular magazines and improve their BCs. The FTX bullet handloads were impressive, especially when looking at their downrange energy. The FTX’s energy at 250 yards is 1,641 ft-lbs. The same metric for a roundnose bullet is 1,076 ft-lbs. That’s an increase in energy of 52.5 percent. Similar increases are seen at the intermediate ranges, too.

Chronograph tapes and bullet holes in paper targets don’t lie. When the data are examined, it is clear the .358 Win. still holds its own as a fine big-game cartridge, as long as the rifleman doesn’t try long “Hail Mary” shots and is careful with bullet placement. The round is versatile, and a bevy of excellent components is available for the handloader.

I say a chicken in every pot, a .358 Winchester in every gun safe!