Research letter info.

[B. Dudley]

The transition period between lifter action to top action was in the mid 20,000s.

The most common scenario encountered is the check-hook lifter action which is a lifter with the long water table and check hook of the top action guns. I would say that not a ton of top action guns without rib extensions were made at the later side of the transition.

I would think that any top action guns without rib extensions after 30,000 serial number would have been specifically ordered that way. I have seen top action guns with no dolls head in the mid 50,000 and even above 100,000. But they were special orders.