Delayed Unlocking

Someone told me that a dedicated Bullseye 1911 can be set up so that the slide and barrel unlock somewhat later than usual, and that this results in a less fatiguing recoil impulse.  The same person said the Rock River Bullseye Wadcutter pistol is set up this way.  This is completely unfamiliar to me.  Would someone explain please?

Talk to Jon Eulette.  Has to do with the shape of the lower lugs when fitting them.