Top 10 Reloaded Handgun Cartridges #9: .460 Smith & Wesson
Date: Jul 01 2021
Smith & Wesson joined with Hornady Manufacturing to introduce a .45-caliber cartridge for the huge X-frame revolver (the same used for the .500 S&W Magnum) known as the .460 S&W Magnum. The case is basically a lengthened .45 Colt or .454 Casull (but with a slightly larger rim) and measures 1.790 inches. The first Hornady factory load was advertised to drive a 200-grain, spitzer-style bullet 2,200 fps. Cor-Bon offered a 200-grain Barnes XPB spitzer at 2,300 fps, a 275-grain XPB at 1,750 fps and a 395-grain cast slug at 1,525 fps.
Most readers are probably familiar with the Smith & Wesson X-frame revolver chambered in .500 S&W Magnum. From the onset, company engineers had plans to introduce other cartridges on this huge frame, and with the popularity of .45-caliber revolvers, this was an obvious choice. With the size and mass of this outfit, it seemed prudent to bring out a longer case that would generate enough power for hunting big game.
Initially a 200-grain spitzer bullet (SST) with a red plastic tip was offered from Hornady and was developed in an effort to increase velocity and effective range for hunting deer. This bullet is short and stubby and even with its sleek profile, turns in a ballistic coefficient of .145 and a sectional density of .140. Early promotions pushed the .460 as a 250-yard deer hunting round. Certainly this can be done, but it is risky at best and only a miniscule percentage of handgun hunters will have the skill to accomplish this. For hunting species larger than deer, the loads from Cor-Bon containing heavier bullets (or similar handloads) are appropriate.
The Model 460XVR (Extreme Velocity Revolver) has some interesting features. Like its big brother the .500 S&W, the .460 is a five-shooter with an outside cylinder diameter of 1.92 inches and a length of 2.3 inches. The frame and cylinder are constructed of 410-series stainless, while the barrel is of 416 stainless. There is an improved muzzle brake that can be removed, if desired. The actual rifled barrel length of this particular revolver is 77⁄16 inches, but with a brake installed overall length is 85⁄8 inches. A fiber-optic front sight is standard but is easily changeable for those wanting a different sight picture. The weight is even heavier than the .500 S&W; while loaded with heavy cast bullets it runs over 5 pounds! This is not a revolver to be carried on the hip and is best in a shoulder harness or a sling for field use.
To me the most interesting feature is the gain-twist rifled barrel. Years back, Smith & Wesson changed its method of barrel making for most calibers to an
EDM (electrical discharge machining) process. By the nature of this rifling, it generally gives best accuracy with jacketed bullets, but being fond of cast bullets, I have mourned this change. This is not to say that these barrels won’t shoot cast bullets well, but the older barrels generally shot them even better. On the other hand, this rifling method allows the factory to make a rather unusual gain-twist barrel at a reasonable cost.
As most readers are probably familiar, gain-twist barrels were commonly used on nineteenth- century cap-and-ball percussion revolvers, as well as many other arms. This rifling typically had little or no twist as the bullet entered the barrel, which minimized bullet deformation and skidding, then began to “gain” or increase its rate of twist, to stabilize the bullet.
S&W has taken this style of rifling to the next level. For example, starting at the breech end, there is an 8-degree forcing cone that is about .275 inch long and beautifully polished. When the rifling first begins, the depth between the lands and grooves is scarcely measurable but slowly increases in depth as it progresses down the barrel. At the same time, the rifling twist begins to gain, increasing its rate of twist. When the bullet first enters the breech end of the barrel and engages the rifling, the rate of twist is one turn in 100 inches but increases as it reaches the muzzle to one turn in 20 inches.
This incredible rifling system would not be possible with conventional barrel-making methods. The electronic process results in a truly precision barrel. The end result is a production revolver that frequently turns in one- to 2-inch groups at 100 yards (with a scope sight).
For the record, the Model 460XVR is capable of firing the .45 Schofield, .45 Colt or .454 Casull cartridges. Just be certain to completely clean those chambers before firing the longer .460 cartridge, or extraction problems might occur.
The revolver used for this article has had approximately 1,150 rounds fired through it. In examining the forcing cone area, some erosion has begun, but it is not enough to change the barrel cylinder gap and has not affected accuracy. For those who shoot heavyweight bullets, the erosion will be minimized. In discussing this point with the folks at Smith & Wesson, they indicated any issues would certainly be covered under the lifetime warranty.
The Hornady 200-grain SST factory load produces significant muzzle flash and concussion, but recoil is not punishing. At 50 yards, groups hovered around 11⁄2 inches using iron sights. When switching to the 395-grain Cor-Bon Hard Cast load, recoil increased substantially, with the muzzle pointing high after each shot, but recoil was slow and not punishing. This latter load also produced noticeably less muzzle blast and concussion. As can be seen in the accompanying table, velocities of the Hornady factory load achieved 2,184 fps, while the Cor-Bon 395-grain Hard Cast load achieved 1,526 fps.
The .460 S&W throat measured .4515 inch. Bullets can be used that run either .451 or .452 inch, but it is advisable to use those that are designed for this much pressure and velocity. The folks at Freedom Arms and I have seen erratic pressures when using thin jacketed bullets that are designed for standard pressure .45 Colt and .45 ACP loads but used in full-house loads in the .454 Casull. The thin jackets can actually increase pressure as they slug up in the barrel. For this reason it is suggested to select bullets designed for the .454 Casull or specifically to handle rifle-level pressures in a revolver.
Good results were obtained using the Barnes solid copper 225-grain XPB, Hornady 240- and 300- grain XTP MAG, Speer 300-grain Gold Dot HP (designed for the .454 Casull) and Nosler 260-grain Partition – all designed to withstand the pressures generated by the .460.
In cast bullet designs, the Mt. Baldy 310-grain plain-base Keith, 335- and 395-grain Cast Performance WLN gas check and Oregon Trail True Shot 360-grain WNFP gas check were tried. When using reduced loads in the 900- to 1,200-fps range, plain-base bullets produced little leading, but when pushed 1,500 to 1,700 fps, leading became a real problem. In this particular revolver, when cast bullets were driven above 1,200 fps, bullets with a gas check proved an important aid in reducing leading.
The maximum overall cartridge length should be held to 2.345 inches. The Hornady 200-grain SST factory load measured 2.275 inches and Cor-Bon’s 275-grain XPB spitzer ran 2.300 inches. No handloads exceeded either length.
Cases manufactured by Hornady and Starline are designed to accept large rifle primers. Some other small manufacturers have made primer pockets to accept large pistol primers. That is something to be aware of before purchasing cases. The accompanying data was developed using Starline cases with CCI 200 Large Rifle primers.
The .460 S&W has a slightly larger rim diameter than the .45 Colt or .454 Casull, with Starline cases running .515 and Hornady .5175 inch. (For comparison, the .45/.454 are standardized at .512 inch.) As a result the .460 requires its own shellholder. Dies are available from Hornady, RCBS, Redding and Lee, with Hornady being used in this project.
The .460 S&W has been entered into SAAMI with a maximum average pressure of 65,000 psi, the same as the .454 Casull. Factory loads are reported to run between 54,000 and 56,000 psi, and I chose to keep the accompanying data within that limit. Above this level, the pressure curve can climb sharply and jump above established limits. There were a number of loads developed, but due to excessive pressure signs or functioning problems, they were deleted from the accompanying data. Often a load would extract easily and not show signs of excessive case head expansion, but primers would rupture and temporarily tie up cylinder rotation.
Based on pressures that were established in a reputable ballistics laboratory, the above problems began to surface when loads went above 58,000 to 60,000 psi. For these reasons I was unable to drive 300-grain jacketed bullets much past 1,600 to 1,700 fps and keep the revolver and ammunition combination reliable. All in all, both functioned better when held under 56,000 psi.
Several powders were used that gave appropriate results, including Hodgdon H-110, H-4227, Lil’Gun, H-4198, Titegroup, Winchester 296, Vihtavuori N110, Alliant 2400, Accurate No. 9 and Western Powders Enforcer. Most of the accompanying data has been pressure tested, but the loads that were not were carefully measured for case expansion using a Mitutoyo electronic caliper before and after firing. As can be seen
in the accompanying table, using 47.5 grains of Hodgdon Lil’Gun, the 260-grain Nosler Partition reached 1,864 fps. When using Hornady and Speer 300-grain jacketed bullets, several powders were able to propel them 1,600 fps, including H-110, W-296, VV-N110, 2400 and A-9, while 44.0 grains of Lil’Gun drove the Hornady XTP MAG 1,730 fps.
It is not recommended to reduce charges below those listed, as pressures can jump erratically, in some instances to dangerous levels. In developing reduced loads, Hodgdon Titegroup was used in conjunction with the cast bullets (due to their low resistance when being driven down the barrel). This combination produced consistent velocities, low pressure and accuracy. For example, 13.5 grains drove the 335-grain Cast Performance WLN 1,175 fps, while 12.0 grains drove the Oregon Trail 360-grain WNFP 1,090 fps. Using the 395-grain Cast Performance bullet, 10.0 grains achieved 936 fps, while 12.0 grains produced 1,047 fps. The above reduced loads were tried at 50 yards and accuracy was reasonable, certainly good enough for hunting.
For those taking larger same where deep penetration is required, the 395-grain Cast Performance bullet can be driven 1,586 fps using 36.5 grains of Hodgdon Lil’Gun. This load performed well but is considered maximum.
As previously noted, the factory loads gave considerable muzzle flash, but it was noticed that most handloads (with the exception of the reduced loads) also gave the same. This was probably due to the combination of muzzle brake and the high pressures associated with this cartridge.
The .460 S&W is a specialized cartridge intended specifically for hunting big game. In my opinion it’s a more versatile hunting cartridge than its big brother, the .500 S&W, and it is likewise capable of taking all game in North America and Africa with correct loads.