.460 Rowland: Not an Elephant Gun, But Getting Close

The .460 Rowland cartridge packs .44 Magnum power in a cartridge the size of a .45 ACP (the case is slightly longer but the bullet is seated deeper). A number of .45 ACP pistols can be converted to fire the Rowland by simply swapping out the recoil spring and barrel. This is an impressive feat, considering .44 Magnum-level semi-automatics were traditionally gas-powered, such as the Desert Eagle, rather than short recoil tilt barrel action.

The .460 cartridge operates at 40,000 psi, twice the pressure of a .45 ACP, but not much more than the 10mm Auto maximum SAAMI spec pressure despite being a good 25% more powerful. A large compensator is required, both to add weight to the barrel and reduce the recoil.

Jim writes about his experiences with his Glock 21 converted to fire the .460

OK, first thing: it didn’t just take the 3 weeks for delivery which was promised. It wasn’t even 3 months. It was almost six months. And a buddy of mine who ordered his before I ordered mine still hasn’t gotten his. So, there’s that.

As advertised by .460 Rowland, the conversion takes like 30 seconds. If you can field strip your Glock, you can do the conversion. I’ve opted for using blue loc-tite rather than red, since it still works well but allows me to remove the compensator easily if I need to.

How does it work? Well, I’ve taken it out to the range several times now, shooting both factory rounds as well as my own reloads. Doing some informal chrono tests, I have gotten exactly the kind of performance promised and expected. The Buffalo Bore 230gr JHP were right at 1300 fps. 200gr RNFP reloads were at 1380 fps, and 185gr XTP (JHP) reloads were at 1410 fps. And those reloads are actually fairly mild — just 12.5gr of Longshot powder — based on what data I’ve seen, I could probably push that to 13.5gr without any risk. (Don’t consider this an endorsement — do your own research, and work up your own loads using published data and standard safety practices.)

Standard .45 ACP magazines are used to feed the rounds (in fact you can shoot .45 ACP +P and .45 Super cartridges in a .460 Rowland gun without any problems). The problem Jim faced was that the .460 rounds were wrecking havok on the Glock magazines. In a follow up post Jim writes about a number of tests he ran to determine what exactly was causing magazine problems …

And most important, it is the *power* of the round, not the case length, which seems to cause damage to the unaltered magazines. Shooting the .460 Rowland power loads in the .45 ACP cases demonstrated this.  Conversely, shooting the .45 ACP power loads in the .460 Rowland cases didn’t cause any magazine damage at all.

Two additional notes I want to add: the first is that I had pretty consistent problems with the heavy Lead Flat Nose rounds in all configurations. They kept getting jammed up in transitioning from the magazine into the chamber. I’ll probably continue to experiment with this in the future, but I’m not too worried about it, since many guns run into some ammo specific problems.


Steve Johnson

Founder and Dictator-In-Chief of TFB. A passionate gun owner, a shooting enthusiast and totally tacti-uncool. Favorite first date location: any gun range. Steve can be contacted here.


  • Lance

    It be better to stay with 100mmm Auto then. I don’t like over pressure cartridges for semi auto pistol the Desert eagle and that Police .40 SW pistols are getting worn out much faster than standard pressure cartridges shows its not worth the trade off. If you want power a revolver can do the job well I don’t see the need to shoot this 200+ rounds in cobat with this caliber. Nether would your hands.

    • Lance

      I mean 10mm not 100mm. Thats a good tank round LOL

  • Bruce Rowe

    Lead is probably getting deposited on the feed ramp causing a jam. Hardening the lead bullet more might prevent the deposit. It could also be the bullets conical shape as well. Sounds like a powerful replacement to the. 45 though!

  • patrickiv

    What damage is it doing to the magazines?

  • noob

    be interesting to design a pdw around this, with a horizontal transverse magazine.

    what would 25 rounds or so of this caliber coming out of a p90 sized weapon be like? especially if it used lightweight AP cored bullets something like the 9×21mm Gyurza bullet construction.

    hydraulically it would be efficient, with a large surface area on the back of the bullet to push against. terminally the wide diameter jacket would shed on armor and a decent sized hardened penetrator could give something like .300 performance.

    the whole package could be very small, with very small magazines compared to rifle magazines.

    • BombedCarnivore

      scale up a PP-19 Bizon. Helical mag > transverse mag.

    • bbmg

      You can squeeze almost the same velocity increases from standard 45 ACP simply by lengthening the barrel to 15″: http://www.ballisticsbytheinch.com/45auto.html

      In any case, it would seem to me that a relatively slow heavy round is a poor choice for PDW ammunition. The P90’s 5.7mm round weighs 6 grams, literally less than half of just the Rowland’s bullet. For the same weight, you can carry more than three of the 5.7mm rounds for every one of the larger cartridge.

      This coupled with much milder recoil and flatter trajectory means a much higher hit probability for the 5.7mm, and one hit from the smaller bullet is going to be much more effective that 25 misses from the larger one.

    • Anonymoose

      They make (or used to make) a MAC-10 conversion kit iirc. Not much for mag capacity, but at least it has been used successfully in a SMG/PCC platform before.

  • AD

    You say in the article that the case is longer than a .45 ACP case, but that you can fire .45 ACP +P through a .460 Rowland gun? Wouldn’t that mean it doesn’t headspace properly?

    • Ian

      The OAL is identical but the case is 1mm longer (possibly 1/16, hazy memory) to prevent .460 from being chambered in a .45 acp.

      Regardless, 460 is an overpressured round for every gun it’s adapted for. The only reason there aren’t stories of KBs is because it is the opposite of prolific.

      • AD

        I’m sorry, but I’m not sure what part of your reply was meant as an answer for my question; just as the .460 wouldn’t chamber fully in a .45 pistol, it seems that a .45 would sit too deep in a .460 chamber.

        I glanced at the linked wikipedia article, it claims that the extractor holds the case in place (then it talks about revolver rounds headspacing using moon clips, which I found a bit strange). This doesn’t sound terribly reliable to me. I suppose the potential gap is probably short enough for the firing pin to bridge anyway, so the worst that could probably happen if the cartridge ends up too far forwards is probably that the gun could fail to extract an unfired round?

        • Some Rabbit

          I agree AD, this headspacing issue sounds creepy as hell. I also have to question using such a hot round in a gun that wasn’t designed for that pressure level. Sooner or later stress cracks will form in the slide or it will stretch.

          • isaac

            The Glock 20(10mm) is known to be able to fire .40S&W rounds regardless of the difference in length because the extractor clip is strong enough to hold the round without properly headspacing. I assume the same thing is in play here.

          • LRB

            The Glock 20 was designed to take the pressure of 10mm at 37,400 Psi. The 460 Rowland is only slightly higher, around 39-40,000

        • John Daniels

          Most people don’t understand what headspace is, why it’s important, or how it’s accomplished with different cartridge types.

    • 1911a145acp

      You are correct. 45 acp head-spaces on the case mouth. 45 acp in an .460 ROLAND chamber has excessive head-space. Years ago I had a Mech Tech upper in .460 ROLAND. The manufacturer’s instructions recommended NOT shooting 45 acp through it because it was “DANGEROUS”. I surmised that since 45 acp was shorter and lower pressure it should be no problem. I CALLED the company and inquired as to WHY it was a dangerous condition and the lady I spoke with could not give a reason. I had shot a few 45 acp in the .460 before with no issues. After about 60 rounds from the bench there was loud whoosh,grey smoke and flame shot out the ejection port. I inspected the fired case- pierced primer. Shot again same result. It appears the extractor was holding the short 45 acp case to the rear against the breechface and the gun appeared to fire normally. After about 50 rounds a ring of fouling built up at the front edge of the longer .460 ROLAND chamber. As the bullet jumped across the chamber and then hit the fowling, pressures spiked the primer backed out against the f- pin and was pierced. Inspecting fired cases you could see the progression of excessive pressure signs and ultimate failure. I have built several 1911s and Paras in .460 ROLAND and overall it is a great performer offering 44 mag ballistics, 8-16 rounds of a larger diameter bullet in much slimmer easy to shoot package. Just my 2c

  • I wonder if a heavier slide might not help. I’m thinking along the lines of a long slide like the Lone Wolf G21L and G21T, or a thicker slide like those used by Guncrafter for their .50 GI conversion kits.

    However, either of these solutions pretty much rules out the use of the existing conversion kit. (A long slide is too long for the existing barrel, and I suspect that .50 GI barrel is thicker than the standard G21.) The remaining option here would be to swap out the OEM compensator for a heaver model, such as one with additional expansion chambers.

    My only worry about cutting out the front of the magazine tube is that rounds might creep too far forward, causing the magazine to snag inside the frame if you try to remove it before it is completely empty. Older S&W Model 39 and 59 autos were prone to this.

  • ric

    I have used the 460 Rowland for years here in Alaska. A Longslide Springfield 1911 with a heavy barrel, no bushing, 26 lb. wolfspring with no problems, I shoot every thing in it, 45 acp, supers plus p’s, Rowland’s made by Georgia Arms, reloads, you name it and this little puppy eats it up and spits it out. Wild West Guns put it together for me years ago. No damage to my mags.