The .500 Linebaugh was the first commercially successful .50 caliber revolver cartridge. John Linebaugh, the progenitor of the round and its namesake, made his mark by converting existing large frame revolvers to fire it—mainly Ruger Blackhawks. These were not the first handguns to chamber self-contained .50 caliber cartridges: that distinction falls on the Remington Naval Model rolling blocks, which first appeared as John Wilkes Booth exited the stage and Andrew Johnson entered it. Coincidentally, Century Manufacturing’s six shot (and six pound) .50-70 revolver followed approximately one hundred years later, and the entirely more practical .50 WT Super—nearly identical to the later .510 GNR—is of similar vintage. Like Roy Weatherby before him, Linebaugh took inspiration from what might otherwise have remained an obscure experiment, saw commercial and practical value where others did not, and permanently altered the course of the firearms industry with his ensuing contribution: the first, though by no means the last, .500 Magnum.
Headstamped brass of the appropriate dimensions is currently available for the .500 Linebaugh from at least one manufacturer, but in former times the cartridge was a true wildcat and strictly a reloader’s proposition. In 1986, protocol required Linebaugh’s customers to trim nearly an inch of material from .348 Winchester hulls, flare out their substantial taper, and ream their interior to accept .510-.512” bullets. Many shooters then and now recoil from such tedium, but the point soon became moot: Winchester discontinued brass for the .348 not long after Linebaugh’s .500 became a phenomenon, thereby threatening even this unwieldy supply chain with obsolescence.
Linebaugh’s answer to this conundrum came in 1988 with his second cartridge, which substituted .475 for .51 caliber bullets and the resurgent .45-70 for the moribund .348 parent case. The resultant chambering, the .475 Linebaugh, soon became a commercial success in its own right, possibly to a greater extent than its portlier predecessor. At the same time, the .500 Linebaugh was kept from an early death by the interposition of alternative suppliers of brass, and the .475 proved to be more supplement than replacement.
Such are the vexations inherent to the firearms trade, where there are few truly self-sufficient operations and the major suppliers are generally inattentive to the needs of nascent or niche markets. We were recently reminded of this reality in a disturbing and unexpected way when circumstances conspired to imperil the future of our own .50 caliber handgun round, the .500 Bushwhacker.
When we first developed the .500 Bushwhacker in 2021, we fireformed Hornady .375 Ruger cases cylindrical and threaded the bases for rims. This allowed us to establish a workable proof of concept, but it was not a practical or cost-effective method for supplying customers with bulk quantities of cases.
For this we turned to the Bertram Bullet Company of Australia and their then-importer, Bertram Brass USA. Bertram provided us with headstamped brass of the appropriate dimensions for a reasonable price and a modest minimum order quantity. At the time, Bertram had been present in the US market for decades, and we saw no reason to expect a change; in fact, all evidence pointed toward the rapid growth of the company, particularly in the area of the precision shooting sports. We were happy with our relationship with both importer and supplier on all counts and expected a fresh shipment of .500 Bushwhacker cases sometime last year.
Quite suddenly and without warning, however, Bertram’s importer announced in the summer of 2024 that they could no longer supply brass to the US market. Bertram immediately sought out new American partners, but their efforts were not crowned with immediate success.
When we learned of this, we made inquiries of several alternative suppliers of brass. All were cordial, but none were able or willing to match the specifications of the original .500 Bushwhacker.
Thus, like John Linebaugh in the late 1980s, we were faced with a quandary. Obviously we could not go on converting guns to a cartridge that depended on a supply of cases that could no longer be replenished. At the same time, we had no interest in dropping support for existing guns or discontinuing future conversions. Accordingly, rather than develop an entirely new cartridge, we opted to preserve the .500 Bushwhacker by altering its dimensions as modestly as possible. As a result, we now have a new cartridge—or rather, a new version of our old cartridge: the .500 Bushwhacker Magnum.
L: .500 Bushwhacker. R: .500 Bushwhacker Magnum
Happily, Bertram is importing brass once again and we are currently in the process of bringing in a new shipment of the original .500 Bushwhacker cases. However, in the interests of avoiding the further interruption to production that would result from the depletion of our brass supply in the interim, we are still pressing forward with the new variant of the cartridge. Once the cases arrive from Bertram, the choice between the chamberings will be elective, but currently, in order to conserve our limited supply of .500 Bushwhacker cases, most guns we convert will be chambered in the .500 Bushwhacker Magnum. Ultimately, both rounds will be permanent fixtures of our catalog.
The primary difference between the "new" .500 Bushwhacker and the original is that it is a belted rather than a semi-rimmed design. From the standpoint of headspace, one is as good as the other. However, the belted case is not without its advantages.
One upside to the belt is that a greater variety of action types will accommodate it than the original semi-rim, which confined the .500 Bushwhacker initially to revolvers and single shots. A rimmed case is admittedly preferable for use in double action sixguns, but no such platform is really suitable for cartridges of this power and magnitude. Such cannot be said, however, for many excellent bolt and even lever action designs (i.e., the Browning BLR), which can more easily accommodate belted than rimmed cartridges. Thus, the .500 Bushwhacker Magnum enables shooters to harness the impressive performance gains offered by rifle barrel lengths without forfeiting the benefits of a repeating action, and this while leaving the door open for a complementary handgun of the same chambering.
Since headspace does not depend on the mouth, a heavy roll crimp can still be utilized with the belted cartridge. As a matter of fact, the quality of the neck tension and crimp of the Bushwhacker Magnum are superior to the original Bushwhacker; the Bushwhacker case was thinner in the mouth than we originally hoped, and we accordingly had to redesign our prototype chamber after receiving the first of our brass from Bertram. The .500 Bushwhacker Magnum features thicker brass and a substantially heavier hull than the original Bushwhacker, and this provides a benefit to case life also.
Load data for the .500 Bushwhacker Magnum differs only slightly from the .500 Bushwhacker, and performance is mostly unaffected by the dimensional changes. I say “mostly,” because the Bushwhacker Magnum can produce somewhat higher velocities and muzzle energies than its predecessor, at least in some circumstances. This is due to the aforementioned differences in brass thickness, crimp quality, and neck tension. These improvements provide the cartridge with an additional safeguard against recoil-induced bullet pull, especially with heavy bullets (500 grains and up), and also ensure greater ballistic consistency and an elevated tolerance for compressed loads.
A standard .500 Bushwhacker sizing die will not function properly with the Bushwhacker Magnum, but with the addition of a new sizer the existing .500 Bushwhacker four die sets will otherwise serve well (those with our old five die sets do not require additional tooling and should use their carbide bulge removal die as a sizer). .500 Parthian and .500 Bushwhacker Magnum die sets are identical, but the latter include a washer to aid the user in setting the sizer properly in lieu of the belt.
All .500 Bushwhacker collet crimp dies now sold function with both the belted and rimmed variants of the cartridge, though collet crimp dies sold in times past will work only with the original case design. The .500 Bushwhacker Magnum uses the shell holders common to the SAUM and RUM family of cartridges, not those appropriate for the .500 S&W and the original .500 Bushwhacker.
As for the standard .500 Bushwhacker and the .500 S&W Magnum and Special cartridges, these will not fire in .500 Bushwhacker Magnum chambers (the original .500 Bushwhacker allowed for this versatility). However, new .500 Bushwhacker Magnum revolvers ship with a dedicated .500 S&W Magnum cylinder, so the multi-cartridge capability of the conversions is not adversely affected by the change.
L: .500 Bushwhacker Magnum. R: .500 S&W Magnum. Note the difference in case head construction.
The .500 Bushwhacker Magnum actually adds to cartridge choice, as it allows the shooter to fire .500 Wyoming Express rounds. These are substantially shorter in length than .500 Bushwhacker loads of either variety, and they also happen to feature a belted design. With full-tilt loads the .500 Wyoming Express is quite a potent cartridge in its own right, and it is naturally more practical to load reduced power ammunition for the shorter than the longer cartridge.
L: .500 Bushwhacker Magnum. R: .500 Wyoming Express.
Initially .500 Bushwhacker Magnum brass will not feature the .500 Bushwhacker Magnum headstamp, but we will eventually make the arrangements necessary to rectify this.
For those who currently own .500 Bushwhacker revolvers and would like a second cylinder chambered in the .500 Bushwhacker Magnum cartridge, they will be available for $500.
The introduction of the .500 Bushwhacker Magnum coincides with certain other changes to our revolver conversions. The principal alteration lies in the design of our standard muzzle brake, which is now 1.5” rather than 1.2” in diameter, with six ports rather than five. Recoil with this muzzle brake is dramatically lower than was the case for our original guns, which were already more manageable than many popular big bore revolver/cartridge combinations, particularly with sensible bullet weights (275 to 450 grains). Going forward, removable bipod mounts and stainless steel picatinny style scope rails will be optional for all .500 Bushwhacker and .500 Bushwhacker Magnum conversions. We also intend to make further changes to our cylinders, but more on that later.
We regret the lost production time caused by the unforeseen, though ultimately temporary loss of access to our primary brass supplier. However, the introduction of the .500 Bushwhacker Magnum allows us to continue offering conversions as we wait to restore that connection. In the meantime, the new guns are better than ever, and we are sure you will find that they are worth the wait.
Please direct your questions to [email protected]
