460 Rowland in 45 acp cases

[SL1]

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

[IllinoisCoyoteHunter]

Bfoosh, this article, with evidence, disclaims what you have stated.

http://www.realguns.com/archives/106.htm

[Clark]

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.

[WESHOOT2]

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.....

[IllinoisCoyoteHunter]

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??

[Edward429451]

I found PMC 45 ACP brass to weigh out as heavy as Win 45 Super brass.

[IllinoisCoyoteHunter]

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.

[IllinoisCoyoteHunter]

I guess the naysayers wish not to comment???? Obviously I have all my fingers if I am typing this reply...

[Edward429451]

RP brass with a 230 gr to 1140. Oh, you must be lieing (sic)

I love it when reality punches nay-saying in the face!

[IllinoisCoyoteHunter]

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.

[Sarge]

I guess the naysayers wish not to comment???? Obviously I have all my fingers if I am typing this reply...
__________________
~~IllinoisCoyoteHunter~~

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.

[IllinoisCoyoteHunter]

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.

My guess would be around 1400 FPS with over 870 ft lbs of energy.

[feets]

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. 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.

[GUNNER454]

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

[Clark]

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.

[OkieCruffler]

Well, my .45 project is a 10" Contender so I can't speak to how the 45acp brass holds up to heavy loads in a 1911 or glock or such. But in my fully (and I mean fully) supported chamber I have run right up to the low end of the 460 and seen no signs of pressure. I intend to run hotter but I'm considering using Starline +P brass for those loads. Recoil from my unbraked barrel is, shall we say, invigorating.