Perhaps some grime moved down into the track that the pawl follows. I assume that you have closed the loading gate when function testing. Removing the cylinder and pin AND replacing them correctly should not affect the function of the pawl.
RCBS makes 500 Special dies, which will work great for the 500 JRH. Have for me! Midway USA Part#s: Product #: 888214 RCBS #: 23812 UPC #: 076683238122
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