460 Rowland in 45 acp cases

OK, you posted a bunch of pictures. Thanks. But what does that prove??? The barrels are obviously supporting the 40k psi 10mm cartridge? Why can't they handle the 40k psi 460 rowland???

So, I will ask the question you failed to answer.

If there is NOT enough chamber wall thickness, how is Johnny Rowland safetly selling these kits for Glocks and Springfields...and even 1911s for that matter?? I would think that the barrels would be of the same construction and thickness, given they are drop-in installations????

Since you know so much more about this than me, please answer the question.

Thanks!
 
I posted about 460 Rowland here on July 2000.
I did the work in May of 2000.
http://thefiringline.com/forums/showthread.php?p=184311#post184311
P32barrelstockandwithfeedrampandmuzzleextensionTIGwelded.jpg

Looks like I welded up the feed ramp of a P32 32acp in 2000.
GlockDSCF0042WeldFeedRamp3s.jpg
Glock22BarrelWeldedrampandchamberre.jpg

Looks like I welded up the feed ramp of a glock 22 40sw in 2002
http://thefiringline.com/forums/showthread.php?p=184311#post184311

CAUTION: The following post includes loading data beyond currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assume any liability for any damage or injury resulting from use of this information.

Instead of working up to a case bulge, that allowed me to shoot more than double charges in 2002 in my Glock 22.
The problem with kabooms in Glocks was not the gun or the ammo, it was the case support all along.

From there I was able to measure the threshold of many cartridge case head failures.

The weakest cartridge commonly available to the strongest:
..Weakest: 10mm
..next weakest: 25acp
..next weakest: 7.62x39mm with large Boxer primer pocket

..The 1889 Mauser case head built with a large boxer primer has been used on many cartridges besides the 45acp ; 22-250, 243, 6mm Rem, 250 Savage, 257 Roberts, 25-06, 260 Rem, 6.5x55 [US made brass], 270, 7mm-08, 7x57mm, 280, 300Sav, 308, 7.62x51mm, 30-06, 8x57mm, 338F, 358, and 35W.

..The 1950 Win .222 case head is very strong, but will give up the primer

..The 1889 Mauser case head with small Boxer primer is so strong that the primer will always pierce before the primer pocket gets loose. 6mmBR handloaders get the firing pin bushed to try to increase that pressure with the CCI450 magnum small rifle primer.

..The rimmed cases are even stronger, like the 38 S&W, 30-30, or 45/70. They may primer pierce or flow into extractor misfit.

What does it all mean?
I have done a lot of experiments, and I know that the 45acp case head is very strong... to answer the OP's question, but it must have case support.
The other way is to cross section the case head and do a Von Misses calculation on the threshold.
It generally gives the same answer and Quickload's prediction of what the pressure was when the primer pocket yielded, in bottle neck cartridges. But in straight wall, QL is not so good.
I can design a test with strain gauge, Wheatstone bridge, instrumentation amplifier, and storage scope to measure the tangential barrel stretch as a function of chamber pressure. That is not a controlled experiment, because the Roark formula for stress vs strain on that complex open ended tube is not known and the variabilities of placing and bonding the strain gauge both add unknown errors. The actual pressure does not matter anyway, what is important is the effect of pressure. With strong guns, that means looking at the brass.

What does all that mean?
I have shot 460 Rowland loads many times with many brands of 45acp brass. The problems are recoil and case support, not the brass. The brass case head is plenty strong. It needs support on the thin case wall over the feed ramp.
 
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If it's so unsafe for a 460R to be fired out of any auto pistol, why do they sell the kits and pistols?

When you see two intelligent men arguing over an issue such as this, you have to look at their individual perspective to see where they are coming from. That usually explains the different views. I see Steve was instrumental in developing the barrels or kits? I see ICH is an end user, home tinkerer, advanced reloader.

There you have it. Steve has a touch of the liability mindset, having worked commercially with the product. These guys have to assume that bubba will do the worst possible things to it and potentially bring hassle back to the company. So they used to saying no no no no no, don't do it.

It has to be possible or the kits wouldn't be on the market. It is entirely possible to tinker in the grey areas safely if one approaches it with common sense and patience in all ways. For any progress to occur, people have to dabble in the fringe areas. Elmer Keith was no bubba, yet he blew up a few guns.

So there's a potential problem area in doing this to an auto. Good point, be careful. That the 460R is a 40K psi cartridge, doesn't mean that it will be run at 40K constantly, that's the max loading. Obviously, the closer to max you are the more precautions are taken. ICH doesn't come across as a bubba. Steves cautions are valid to a point, but his position seems to not be able to account for anyone between a bubba, and a commercial operation who's position must be no liability. A shame in a way because it makes Steve appear a little arrogant about it.

Either way, I'm glad my 460R loads are only for a BH revolver. No case support issues there with Rugers tight chambers.
 
Very well put, and I will be the first to apologize to Steve for being rude. Sorry Steve for being a hot head.

I would like to thank everyone for all their input....Steve, this includes you!

Clark, I would especially like to thank you for taking the time to submit such informational posts. Wow!

I will keep eveyone abreast of this project as it materializes. Unfortunately, I still have lots of research and other financial obligations at the moment. It WILL happen, trust me.

Thanks again!!!
 
Like so many have pointed out... the .45 ACP barrels do not offer enough support at the rear of the case. Loading .45 ACP brass to .460 pressures and firing them in an un-supprorted barrel is asking for problems. .460 Brass is much thicker at the base than .45 ACP. And as for the revolver fired .45 ACP loaded to .460 Rowland pressures... that is far different than a 1911.

No offense intended, do as you see fit. I was just trying to steer you away from an ill advised "idea". If your "idea" would work .... there would be no such thing as .460 Rowland brass.... since there would be no reason for it.

I've owned a .460 Rowland conversion kit for my Para Ordnance for well over a decade.

Again do as you see fit... you asked a few questions and we ( The Firing Line posters ) have answered with our advice.
 
Has anybody checked to see what steel and what hardening processes are used for the 460 Roland conversion barrels? Is it different from the steel/hardening used for the stock .45 ACP barrels?

I know that Ruger sometimes uses different steels for the same gun when chambered for different cartridges. For example, the Super Redhawk uses one steel for the .44 Magnum, but another for the .454 Casull. So, rechambering the .44 Magnum guns to the .454 cartridge will lose a lot of the margin that Ruger intended for safety purposes.

SL1
 
10 years ago, I was not able to get the same measurements of 45 Super case webs as Joe D'Alessandro [The guy who is realguns]. I have nothing but good things to say about him, and I don't know if one of us is making a mistake, or that is just a variation in batches of brass. He was already doing 45 Super when I started 460 Rowland in May 2000. Later he did 460R.

I get 45acp, 45Super, and 460 Rowland case heads cross section the same. 0.180" thick webs.

The only one different is Starline +P 45acp, with much thicker walls. It weighs more and holds less powder.

I talked to the man at Starline 12 years ago, and he said that the +P is for guns with poor case support.

I have an Aluminum framed officer size 1911 with feed ramp intrusion to .235".
I have been able to shoot 45 Super pressure level loads in that pistol, using the +P brass.
But that is on the hairy edge of how much recoil I can take and still be aiming.
 
10mm vs 45 'extra'

I, too, used a Jarvis barrel (fit by him) in my M20.

Trust Clark's experiments.

Consider goal vs risk.



I kept a 44 Redhawk around; I do my stupid stuff mostly in 9x19 now.
Nowlin barrel.....
 
Glock 21 in hand, Jarvis barrel on order (4 weeks out, according to the fellow at Jarvis). Going to round up some springs and guide rod.

Clark, would you recommend the Starline 45acp +P brass??
 
Began load development with 230 XTPs and Longshot. Worked up to 9.5 grains (.5grn under 460 starting load) and was getting 1140 FPS out of the G21 with Jarvis barrel. Had o seat them to 2.00" so I was quite wary and started low. I will probably switch over to the Lee 230 TC as I can seat that out a touch more than the XTPs. With a 24# recoil spring and standard spring in the mag I had zero FTF or FTE. I will try to work the 230TC up to around 1300 FPS if possible. I was using RP brass. Cases showed no signs of bulging and the empties chambered just as smoothly as a resized case. :D
 
I started out at 8.0 grains longshot, which gave around 1000fps. 8.5 gave me 1050 fps, 9.0 gave me 1100 fps and 9.5 gave me 1140 fps. With the 24# recoil spring, the brass was thrown about 3-4 feet away from me with the 8.0 grain load and about 12-15' with the 9.5 grain load.
 
I guess the naysayers wish not to comment???? Obviously I have all my fingers if I am typing this reply...
__________________
~~IllinoisCoyoteHunter~~
Click to expand...

Now THAT is the most ridiculous thing I've ever seen on a gun forum. Obviously, you've never seen me type. ;)

Don't blow your eye out, Ralphie.
 
Had a chance to do more testing today but didnt have my chrono. Loaded up some 200 grain XTPs with 12.0 and 12.5 grains of Longshot. They all went bang and fed with no issues. I will be shooting the 12.5 grain load over a chrono when I get a chance. After I see the velocity I will decide if I want to test the waters any further. :D

My guess would be around 1400 FPS with over 870 ft lbs of energy.
 
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Keep in mind that different metals fatigue in different ways and at different rates.
Brass will work harden and fail with time. If the case walls are a bit thin where the ramp meets the chamber you will probably see them rupture before they fail. They survived multiple uses so far and will probably not bulge over the ramp.
The steel for the barrel is likely to develop microscopic fissures that will survive unnoticed for a long time. Then, one random day, a standard 45 ACP load will rip the chamber open.

Unless there is a serious overpressure problem it's rare to see one or two rounds pop a gun. What you find is that the damage accumulates over a period of time.

I would be far more tempted to try something like this in a revolver than a bottom feeder.

Have you inspected the frame and slide for signs of battering? Check all contact surfaces. The high strength barrel will probably be the last thing that fails. Check the rest of the gun around it.

I remember someone going down this road back when the 460 S&W came out. He was battering an X frame with his version of load development. Others referred to it as building a hand grenade. That guy's version of safety was to stand behind a tree and pull a string tied to the trigger. If the gun didn't blow up, he'd fire the rest by hand.
We're talking compressed charges of H110 under 250 gr XTPs. That's well over 50 grain of powder. :eek: Velocities were disturbing.

In the end the gun did not pop but it was badly battered and very loose. It's now one of those "cheap" used X frames that will explode on some poor buyer down the road.
 
Comp for 460

From what I have seen in the comps they are ported. This does allow the gases to escape faster rather than having to wait to escape at the end of the barrel
 
Per Hayes "Elements of Ordnance" the center of mass of the gas will be considered to move at 4,500 fps.
The forward momentum should be [bullet mass] [bullet velocity] + [powder mass] [ 4500 fps ].
Per Newton's 3rd law of motion the recoil must be equal and opposite of the sum of the momentums of the projectile and the gas.

That equal and opposite stuff is not in energy [1/2][mass][velocity squared].
It is in momentum [mass] [velocity].

If the recoil compensator vents the gas sideways to the barrel, it no longer adds to the recoil.

If the recoil compensator vents that gas in a backwards direction, it subtracts from the recoil.

In 460 Rowland, getting case support is easy, dealing with the recoil is hard.
 
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