Clark, I have a 470NE 140-2 safari double, and I have not had any problem with the safety, though the recoil is fairly heavy with my handloads! I also have a Merkel 140E 9.3X74R with an auto safety, and though the recoil is much lighter, I haven't had any issues with that safety either.

I've had the 9.3 for five years, and the 470NE for two years, with absolutely zero problem from either of them! That isn't to say I won't have a problem in future with one or the other, but not so far!