460 rowland no conversion

[Cycletroll]

I shoot Rowland level loads out of a .45 ACP chambered Lone Wolf barrel in my Glock 21. I use a 24# recoil spring and a LW compensator.
You must use a fully supported chamber because if you don't you will start bulging the brass down the feed ramp at .45 Super levels (~28k psi).
With a well supported chamber extremely high pressure loads are possible but then slide speed/battering becomes the problem. With a 24# spring and comp I shoot 250gr XTP's at 1250fps or so and 185gr Barnes XPD at 1475fps as well as 275gr Hunters Supply lead WFN @1250. These loads handle in the gun fine, Winchester brass is thrown 5-8' and recoil is not too bad.
Basically I have a light, high capacity (13+1) all weather auto that shoots midlevel .44 mag or Ruger level .45 Colt loads.

Good thread on Glocktalk following this exact subject:
http://www.glocktalk.com/forums/showthread.php?t=1382239

 

[SDGlock23]

As CT mentioned, you can load the .45 Super to some impressive levels.

I use a KKM Glock 21 compensated barrel which has very good chamber support, which is a must really. I use the comp provided although I have another on the way that should work better, but the short of it that you can load the .45 Super to 460 Rowland levels as long as you have the right setup.

The barrel with threading runs right at 5" long and here's some of the numbers I've got so far, and could run them a little warmer but I'm not sure I see the need, performance is awesome and the recoil is plenty as is. This is with Starline .45 Super brass out of the above mentioned KKM G21 (.45 ACP) barrel.

300gr hardcast (Beartooth LFNGC) @ 1,150 fps
275gr hardcast (Hunters Supply) @ 1,200 fps
250/255gr hardcast/JHP (Hornady XTP, Beartooth WFNPB hardcast) @ 1,275 fps
230gr XTP @ 1,300 fps (could push faster but the bullet is only rated for 1,250 fps)
200gr XTP @ 1,475 fps (exceeds bullet rating by 225 fps)
185gr XTP @ 1,575 fps (Hornady rates the 185 XTP to 1,450 fps...so this is a little bit of overkill)

I couldn't ask for more really in a relatively light weight 13+1rd handgun.

You would save yourself a lot of hassle by just loading up .45 Super brass instead of cutting 460 Rowland brass. The same setup above shoots regular .45's just fine, although they feel like a .22 in comparison.

 

[Cycletroll]

2nd on saving your money on brass. Standard Winchester .45 ACP brass is a very strong design and will handle pressures way past .460 Rowland levels. The brass is not the weak link. Proper chamber support/barrel strength and managing the recoil/slide velocities of heavy/fast loads is the real issue. I have used Starline .45 Super brass and it functions no differently than standard Winchester brass.

 

[SDGlock23]

I would have to say CT is right, I've also seen elsewhere other people using .45 ACP brass to load to 460 Rowland levels, just make sure your platform is up to the task!

 

[Clark]

http://www.thehighroad.org/showthread.php?t=95546

We were experimenting in 2000, but by 2004 there seemed to be a settling out of the 460 Rowland problems.

 

[lmcl123]

With respect to cutting down 460 Rowland brass to 45 specs. I have heard that Starline Brass makes their 45 super brass to the same pressure specs as their 460 Rowland brass. I emailed them to find out if this was the case. It was. their exact quote was as follows.

"There is actually no SAAMI standard on pressures for the .45 Super or for the .460 Rowland. However, the Rowland is not recommended to be loaded more than 40,000 CUP and the Super isn’t recommended to go over 35,000psi. But our Super case and Rowland case are actually identical to each other except for the case length. So to answer your question, our Super brass probably is that tough, in the right gun."

So save your self some trouble and buy Starline 45 super brass.

 

[Grump]

I've spoken with the patent attorney who worked with Rowland on the intellectual property side of this a few years ago, and the compensator IS intended as part of a complete system which delays unlocking as long as possible to reduce stress on the case during unlocking and extraction.

Sure, pressures can be down to 10,000 psi or so on bullet exit, but those pressures also do NOT vanish to zero (differential to ambient) at that instant either. I'm not sure that the toughest .45 family case could withstand 10K psi when extracted 1/4-inch.

Personally I was skeptical at the time about the claims of the compensator being "necessary", but now I accept as real the idea that it makes a difference both in the long run (repeat firings on the same case) and for the one in 100,000 or so chances of something just having a serious violent disassembly event.

There was some advanced mechanical engineering going on with the Rowland, which included calculation of force vectors and stuff I know is real but I cannot personally calculate.