When did they dimple my mag tube?

[Hedgelog]

When did Remington start using the bayonet style plugs, with dimpled mag tubes, on the express? They must have implemented this much earlier on the 12 gauge since I run across many 20's with the old internal friction retainers, but the 12 seem to be scarce.
Also, does Remington now use the dimpled tube on the Wingmasters?

[Synchronizor]

Bayonet style plugs?

I'm not sure when Remington introduced the internal ratchet system, or which gauges came first. I have seen the new-style plastic spring retainers on new Wingmasters, though.

[badboybeeson]

I think it was In the mid 1990,s