.460 Rowland -VS- .45 ACP Hot Handloads?

B

BluRidgDav

New member
I have a Glock 21 Gen 4 in .45 ACP that I want to convert to shoot .460 Rowland ammunition, and I also handload.

So far, my research has found that the only difference between these two cartridges' dimensions, is that the case length of the .460 is 1/16th inch longer than the .45 ACP. This was done, to prevent higher-pressure .460 rounds from chambering in unmodified .45 ACP pistols. But, the overall length of both cartridges is the same, due to the same magazines being used for both. Therefore, bullets must be seated more deeply in the .460 and powder capacity remains the same. I also learned that a compensator must be used to delay/reduce rearward slide velocity and that a stiffer recoil spring is required.

But, if I buy a threaded .45 ACP barrel, compensator & 24# spring from Lone Wolf, can't I just handload .45 ACP cartridges to achieve .460 Rowland ballistics?

If yes, I will probably leave the compensator permanently attached to the barrel and just swap springs when I want to switch between different ammo loadings. I also plan to load only hard cast lead bullets in the high-pressure (.460 level) ammo, and only jacketed bullets in the milder (.45 ACP level) ammo, so that I can choose the correct spring.

Informed opinions & suggestions are appreciated.

Thanx, Dave.
 
As one that's had a great deal of experience with pistols utilizing compensators you'll find how much of a chore it is to clean the compensator to keep it effective if you shoot cast bullets. Also to get the full benefit of the 460 Rowland you would be better off using a revolver lengthening the cylinder chambers to fit the longer 460 brass.
 
But, if I buy a threaded .45 ACP barrel, compensator & 24# spring from Lone Wolf, can't I just handload .45 ACP cartridges to achieve .460 Rowland ballistics?
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I would be concerned with how well supported the case head is before I started talking about .460 Rowland pressures in .45acp brass. 21k psi to 40k psi is almost double the original pressure. .45 acp brass has a strong enough case head, but the web is fairly thin just forward of the case head. Me personally, I would trace the unsupported portion around the feed ramp on an empty shell casing, then cut it in half to ensure the web of the case is completely supported. Then work up slowly.

As one that's had a great deal of experience with pistols utilizing compensators you'll find how much of a chore it is to clean the compensator to keep it effective if you shoot cast bullets.
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The man speaks truth, I would probably stick with all jacketed ammo honestly. MAYBE powder coated cast would do OK, but anything requiring bullet lube will be a PITA.

Also to get the full benefit of the 460 Rowland you would be better off using a revolver lengthening the cylinder chambers to fit the longer 460 brass.
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.460 and .45 acp have the same OAL as they both have to fit the same magazines. The length of the 460 brass is only to prevent it from fully chambering in a .45 acp firearm and not to provide a larger case capacity. Both cartridges have nearly identical case capacity (45 acp may actually have a bit more due to the thinner web of the case).


Do as you wish OP. I wouldn't have any qualms about approaching 45 super pressures with 45acp brass given the right conditions. I personally probably wouldn't push .460 Rowland pressure out of 45 acp brass. I'm not saying it wouldn't work, what I'm saying is that would exceed my personal comfort level threshold. We are two different people, however, just be careful.
 
OP,you have hit on key factors with the Rowland.All that is good to understand.

Starline makes a high strength 45 brass that IIRC is called the 45 Super.I have no experience with it.Go to Starline site.

My concern is Murphy's Law. If it CAN go wrong,it WILL go wrong.

What happens when a 1911 or Glock magazine inadvertently gets loaded with 45 ACP at Rowland pressure and you,a friend,a relative,or even a stranger fires it in a non-ramped barrel ,non-comped stock pistol? At least goose egg brass,but maybe a blowout.

I'd suggest your swap kit include a barrel in 460 Roland.I think Clark still makes the kit.
Then you still have the 45 ACP original barrel that came with the gun.

You also may find,if you do follow your original plan,that your comped gun tuned to run at 460 Rowland pressure is just too much comp for the gun to run at45ACP pressure,light springs or not.I don't know that for sure,but do your research
 
If you are going to the trouble of buying a new barrel and comp, why not go all-in and get the Rowland?
If you want to just improve ballistics without spending much money or doing a lot of tinkering, try .45 Super.

A buddy of mine put a comp on his Glock 20, and even shooting loads over printed max, and using a very light recoil spring, spent cases were just dribbling out of the port, sometimes not getting out.

A problem that then surfaced was the recoil spring being no stronger than the striker spring, and you could see the slide moving rearward when the trigger was pulled; definitely an unsafe condition.

I shoot .45 Super in a modified 1911, and without doing a lot of load development, I got 230 grain bullets up to an average velocity of 1175fps, and with some more work could probably get another 50fps from my six-inch barrel.
.45 Super, while hot compared to .45 ACP, runs at lower pressure than 9mm, .40, or 10mm, so, unlike .460 Rowland, is not really a hot round.
 
Thanx Guys. Those are some good things to consider.

Hunter - Do really hard-cast, gas-checked, lead bullets dirty up compensators? It seems that most .45 ACP shooters use relatively soft-cast lead bullets in their comp-guns, since they are not pushing for high velocity and because soft-cast bullets are cheap. Also, if I wanted a revolver, I would just get one in .44 Mag-.500 S&W. I want the most powerful Glock platform that is possible/practical.

whiskey - Thanx for the heads-up concerning .45 ACP brass thickness around the web. My research so far, had only revealed the external dimensional differences, not the internal ones.

BC - I will look into that .45 Super brass from Starline. I'm not worried about mis-matched ammo & guns, since I don't share my reloads with anyone. Clark doesn't list any .460 Rowland parts on their website (especially for Glocks), only loaded ammunition.

Rick & BC - Since all of the compensators that I've looked at, so far, require Loctite and sometimes set-screws to hold them on, a .460 chambered barrel would not allow me to "easily" switch back to .45 ACP. Compensator tuning & compatibility may also make swapping back & forth a problem. I was just hoping for an simple solution. Since, changing recoil springs in a Glock only takes about 15 seconds.

Thanx again, Dave.
 
.460 Rowland ammunition is pricey stuff. Starts at $22.49 per 20 at Midway. Starline brass is currently on sale there at $29.24 per 100 or $130.49 per 500. Might be an idea to jump on the brass.
"...can't I just hand load .45 ACP cartridges to achieve..." Nope. Just like you can't load .38 Special to .357 pressures or .44 Special to get Magnum pressures. The Rowland is 62 thou longer than an ACP. There's no shortage of Rowland brass anyway.
"...they are not pushing for high velocity..." Because you can't do that without causing leading. Even with a hard cast bullet.
 
I also learned that a compensator must be used to delay/reduce rearward slide velocity and that a stiffer recoil spring is required.
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Says who? and more importantly, in what gun???

You don't need a compensator, as such, but you could need the mass of a compensator. The point of the exercise is that since you are using a higher pressure round, the slide gets slammed harder, which = faster, which means

A) the faster moving slide exerts more force on itself and the frame when it gets stopped,

B) The change in slide velocity might affect the unlocking cycle, possibly allowing the gun to unlock before it should.

They way you reduce this is to reduce the slide velocity back to "normal" while still firing the high pressure round. Adding mass to the moving parts, and additional (slight) resistance with a stronger spring.

The benefit of a compensator here is not the comp effect of redirecting some of the gas to offset recoil, it is the mass (weight) of the comp device. A solid (without compensator holes or slots) muzzle device would provide the same benefit. More weight, slowing down the moving parts.

That is why I said a compensator isn't needed. A compensator is, however the easiest, simplest way, and having the holes in it to work as a compensator (as well) hurts nothing and gives you the additional benefit of further reducing the felt recoil.

so, "need", no. Use? oh yes.

GLocks are famous for having less case support in the barrel than other guns. This is not a good thing for higher pressures. I don't do Glocks, can't tell you what to do, specifically to adapt a Glock .45 to higher pressures.

GLock knows, as their .45GAP round is higher pressure than the .45ACP. However Glock has a history of only doing what Glock wants, and sharing info on how to improve what they consider "perfection" has never been high on their list of things to do.

Different designs handle the same thing (higher pressure) in different degrees. I had a load that would launch a Speer 200gr JHP from a 4.25" barrel SIG at a clocked 998fps. Recoil was "snappy" but there were no pressure signs on the fired brass. Same ammo run though a "pin gun" set up 1911A1 cratered primers of every round.

There is no physical reason you can't load a .45acp case to match the Rowland pressures. There are PRACTICAL reasons why you should not do this (like loading .357mag pressure n .38Spl cases, it can be done, but should NOT BE!!).

If you are going to run higher pressures in a Glock, I would seriously consider replacing the factory barrel with an aftermarket one which has a more supported chamber. TO start with...

Also remember that doing anything to the gun, including shooting reloads, voids Glock's warranty. I don't know if they still are, but at one time they were very picky about that.

Go into this with your eyes (and wallet) open, and expect that IF anything bad happens the cost will come out of your pocket, and only your pocket.

Good Luck, be safe!
 
A compensator does more than just add weight to moving part or just redirect gas upward. When gas hits the baffle plates, it applies a 'forward' force on the comp/barrel. This helps to slow down the barrel/slide rearward movement to increase lock time.

https://americanhandgunner.com/compensators-do-they-really-work/

Also, a compensator, or ports, vent gas pressure in a direction different than that which the bullet travels. Since gas adds to the recoil force, venting it in another direction prevents it from going straight forward, which reduces it's contribution to the rearward reciprocal force that adds to recoil.
 
44 AMP said:
Says who? and more importantly, in what gun???
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Rowland says so. https://www.460rowland.com/about/

"CONVERSIONS
The increase in slide velocity over a standard .45 ACP, or even a .45 Super round, cannot be properly controlled with an increase in recoil spring rate alone. Autoloaders properly converted to fire the .460 Rowland® Cartridge require a compensator or a ported barrel to ensure reliable, long lasting, operation. This fact not withstanding, there continues to be customer demand for a "stock-looking" .460 Rowland® conversion; however, any effort to answer this demand is thus-far not supported by the Inventor. Rowland still maintains that a properly designed .460 Rowland® Conversion requires an effective compensator to momentarily delay slide action until the very high pressures developed by his cartridge dissipate to more manageable levels. Without this compensation, slide or frame failure will result over time and reliability will suffer in the short term. "
 
The folks I know who burn a lot of ammo through comps mostly use Montana Gold bullets with jackets that enclose the bullet base. Hot gas does not contact the lead. They don't shoot the conventional hardball with exposed lead at the base.

Jetting gas has something to do with it.Just shooting cast bullets,I've seen leading in the throat of an old,good Kimber with 45ACP target level loads and Lazercast bullets that were undersize to seal the bore.

After I bored the gas check feature out of my Lyman 429421,no gas checks,I've fired thousands of rounds through my SBH 44 magnum with full power (H110,one token grain under Max) loads with never a leading issue. Bullets pure wheelweight.The bullets fit.No gas cutting.

I'm another who says the effect of a comp on a 1911 is far more than mass.

I gave my brother an old school 1970s vintage single stack 38 Super race gun made by Guncraft for a championship shooter by Ben Jones.
That gun saw very high round counts of over 40k psi Major loads.Its still shooting at well over 40 years old.Its still a superbly tight,smooth,and slick.Its not worn or beat.
The key is,with those over 1400 fps loads,the comp allows...demands...the use of recoil springs between 9 and 12 pound rate.

This brother actually got hold of a high speed camera to study keeping the muzzle flat and develop the smoothest cycle.

A well set up 1911 that is happy with a 12 pound spring,or even less,will run a long time.
Its the 24 lb spring that beats them up.
Without recommending it,folks are twisting 9mm up to 1400 fps major levels by way of comps.

Why? Its got to do with finding your Starline 38 Super Comp brass after a stage.
 
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thanks for the link, some interesting info there.

I'm not going to argue with the inventor, but I do note he's talking about conversions. And for conversions of existing duty class semi autos, I can see his point.

I suppose I got as bit confused, as I have a pistol that I could easily convert to .460 Rowland, without needing in a compensator. And I have another pistol, that I could fire .460 Rowland in without any conversion...

Though neither is a duty class semi auto, and the .460 Rowland would actually be a step DOWN in power....

Any guesses what they are????
:p:D
 
I have used a Glock 21 with KKM 4 port comp to load .45 Super to 460 Rowland levels, it works. If you get the throat reamed you can even play with the heavy .45 bullets (250-300+gr). The only downfall really is that at top end levels I felt like I was really putting a beating on the Glock. To shoot them some is okay but overall I felt it was a bit too much power for a Glock frame (some rounds 1000+ ft-lbs) so I settled on mid range stuff, like a 250gr Gold Dot @ 1100 fps.

Either way it's cool, you can load it up or down to whatever you'd want.
 
Not a wheel gun, though that was a fair guess.

Congrats 74A95, you hit the one right on the head.

LAR Grizzly .45 Win Mag.

While I haven't actually done it, I'm very confident that if I dropped a Grizzly barrel in .460 Rowland into the gun it would run just fine and without a compensator.

I do also have a Wildey in .45 Win Mag. Converting that one to .460 Rowland would be much tougher, and pointless.

The other one I have that I could shoot today, if I had .460 Rowland ammo is my Contender. I have a .45 Win Mag for that as well, and it will fire .45ACP because the extractor holds the case in place, and it would do the same for .460 Rowland as well. The chamber is, of course, too long for best results, but they will fire.

Since the .45 Win Mag throws its slugs a couple hundred feet per second faster than the Rowland, I have no concerns with the guns taking the Rowland pressure.
 
Thanx Guys!

Here's what I've learned from this thread and some reading on the side. Management of the .460 power levels can be controlled in three different ways:

1. Compensator - uses the impact of muzzle gases against angled surfaces to push the barrel forward and delay it from unlocking until pressure levels drop somewhat, and also re-directs some of these gasses upward to reduce muzzle flip & perceived recoil.

2. Stiffer Recoil Springs & Buffers - resist & slow the rearward velocity of the slide, and reduces battering of the pistol.

3. Heavier Slide - a longer slide containing more metal, and/or attaching slide mounted optics, sights, etc, will help slow the rearward velocity of the slide with their added mass. But, since compensators are attached to the barrel, and not to the slide, that mass doesn't slow down the slide.

Did I get those right?

PS - I'm still a little fuzzy about how hard-cast gas-checked ammo, which has been successfully used in auto-loading handguns for years without causing leading issues, suddenly becomes problematic when passing through a compensator?

Thanx, Dave.
 
Something to keep in mind is, there's also such a thing as froward battering. Stiffer recoil springs contribute to this..................If you want to slow slide speed think about a square bottom firing pin plate and stiffer mainspring
 
If you want to slow slide speed think about a square bottom firing pin plate and stiffer mainspring
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Excellent tactics for 1911, not as much for a Glock.

I'm still a little fuzzy about how hard-cast gas-checked ammo, which has been successfully used in auto-loading handguns for years without causing leading issues, suddenly becomes problematic when passing through a compensator?
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No one is saying you cannot use cast bullets, just that cleaning will need to be done more frequently. Cast bullets using bullet lube do foul guns quicker. Same with compensators. For compensators to work as designed, the gas needs to hit a flat surface to be directed. Bullet lube gobbed up in the compensator may make it less effective. Hunter can probably attest to this better than I. I have no clue how much of a difference it would actually make.
 
Mr Hunter is a Master. I'm an amateur hobbyist.

The 1911 is better at absorbing energy from the slide moving to the rear than it is at absorbing energy from the slidemoving forward. Pretty much,forward energy gets transferred to the steel contact between the slide stop pin and the hole in the frame.
The pistol smith works hard at getting the barrel underlug,slide stop,link,lockup all just right.

Adding weight to the reciprocating mass makes for a bigger hammer.Adding recoil spring rate swings the hammer harder.

The recoil spring rate is actually more about stripping and chambering a round.

There is a timing associated with that.It takes time for the magazine to lift a round to feed. A 24 lb spring allows less time than a 16 lb spring.

I'm no expert. John Moses mostly designed for 14 to 16 lb springs.So,I'll push a little,to an 18 lb spring. I can find that by using a 20 lb spring to just activate the slide stop,then back to the 18.
And,yes,the squared off firing pin stop plate and stiff mainspring are another place to slow the slide.

My theory is to load to the spring,rather than spring to the load.If I need more than an 18lb spring,maybe I need a different load.Thats me.

However,as I said before,a properly tuned compensated gun may not need heavy spring. There is a Ben Jones Guncraft 38 Super in the family that is tight,sweet,and slick ,reliable and accurate after 40+ years of over 40 kpsi loads.Recoil springs run 9 to 12 lbs. That's like Gold Cup bullseye.

The comp does its job. There are some very efficient comps available for Glocks.And there are powders that up the efficiency of the comp.

On leading with gas checks through a comp: In my experience,fullpower 44 magnum revolver of wheel weight don't lead a non comped hand gun IF THE BULLET FITS. Undersize bullets get gas bypass and they lead,even in a 800 fps 45 ACP.

Is there gas bypass in a comp? You bet!

The build up problem is not bullet lube,its bullet metal.Lead. And its not just cast bullets. Common hardball bullets with open,exposed lead bases will lead foul comps. The race gun guys commonly use bullets that expose no lead to the gas.
 
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