The earlier Model 25's and some early 625's will handle .45 ACP's with out the clips (headspacing on the mouth of the case).

Smith made a decision on the later 625's to NOT follow the original protocol and the later units REQUIRE moon clips for proper headspacing.

My 625-6 and 625-8 revolvers require the clips (or the use of .45 Auto Rim cases).

Dale53