All of my "newer" Colt 1911s (1977 on) rattle with the best WWII guns. My first year 10mm Delta Elite is among the loosest I've handled.

Colt professes the sloppy slide to frame fit doesn't hurt accuracy and indeed is necessary for reliability.

My Wilson Combat CQB 45 and Dan Wesson PM7-45 have essentially no slide to frame looseness and have maintained 100% reliability from day one.