Check this thread...
plus p in sr1911
but as a preview, I asked Ruger and got this...
All Ruger 45 caliber pistols are chambered for the .45 Auto cartridge and are compatible with all factory ammunition loaded to U.S. industry standards, including high-velocity and hollow-point loads, loaded in brass, aluminum or steel cartridge cases,
as well as +P ammunition. No 45 Auto ammunition, manufactured in accordance with NATO, U.S., SAAMI, or CIP standards, is known to be beyond the design limits or known not to function in these pistols.