45 super in a glock 21

[Leadingall]

Ok, so I picked up some 45 super from underwood and I want to run it through my G21. I know I need to beef up my recoil spring so I'm about to order a guide and spring set up from lone wolf. My question is: do I need an aftermarket barrel to run this ammo? I've read that there is no case support in the factory chamber for the 45 super but the round seats identically to standard 45 loads when placed in there. It looks like it will function fine in the factory barrel, has anyone worked with this high pressure ammo through the oem barrel?

[Varg Vikernes]

http://tomblalock.hubpages.com/hub/How-to-Convert-a-Glock-21

This seems like a good guide.