In discussing the SR-762 recently the topic of carrier tilt came up, which is an issue that has plagued piston-equipped AR-15 type rifles for a long time. Ruger’s own SR-556 rifle had its fair share of carrier tilt problems at release, but after a year of working the kinks out the rifles from early 2012 or so onward seem trouble free. Other manufacturers worked out their own fixes, but it seems like a common thread between them is reduction of part of the bolt carrier body. This is the fix Ruger opted for in the SR-762, pictured below.
The step down is about 0.185″, meaning the tail of the carrier would have to tilt half of that downward from the force of the piston rod impacting it in order to cause any problems. Also note the lack of lightening cuts in the front portion of the carrier to balance the overall weight out. I wish Ruger had put similar thought into the trigger group.
The lower is also uniquely reinforced near the threads for the buffer tube, shrouding them from impact. Typically carrier tilt involves the bottom edge of the carrier tail slamming into the edges of the buffer tube and damaging the tube, the threads or both.