Some info I found off of a GLOCK website chat room..

"Hey Guys,

I used to read the threads here about the 45 super and 460 rowland development (both loads and barrels/comps) with great interest but never invested financially into it. Figured my G29 would suffice. But, I've gotten bored with the 10mm and have some disposable income now to play.

The reason for this new thread is, I am wondering if there are any definitive conclusions as to the best way to setup an all-purpose G21 for 45+P up to 460 Rowland loads. I have a stock Gen 4 21 and would like to have a set up for 45 acp+p / Super for home defense and be able to shoot 255 gr cast as powerful as the gun can withstand within reason as a sidearm when packing out moose up here in Alaska and camping. Reliability of a wide range of loads is most important.

Some specific questions:
Are there actual problems with 45 acp cases being fired in a 460 chamber?
If so, can the 45 super chambering (aftermarket barrel with "full" support) and brass handle 460 level loads?
What are the pros and cons to the many different comps out there?
Is it too much to ask to have one G21 set up to shoot 45 acp+p and 460 rowland reliably?
If you were to start from scratch, with a gen 4 21, what would you buy and from where?

Thanks for any and all information,"

while I believe a 454 Casull or 460 Smith&Wesson have more power, not sure all of that is needed in the heat of the moment..pretty sure in visiting with those who live in AK and have used this type of firearm, the 460 Rowland would do the trick..

It does appear you need a compensator to slow the action down which is what they stated during the seminar I was at as well..might tinker with one of these for something to do..who knows..find it interesting at the minimum....

Ripp