Winchester Model 21 forearm question update history

I understand a change was made to the Model 21 forearm locking design which in my opinion was a poor design for such a fantanstic gun. The change was identified with a red dot on the release metal. Does anyone know what the change was ?

 

it had something to do with a screw in the iron to aid the unit from not loosening.

i found this on the winchester collector website.............

Improvements to address the forearm loosening issue on the Winchester Model 21 primarily involved strengthening the fastening system and, on later models, adding a specific screw and recoil lug in front of the forend iron to combat recoil forces. Earlier models were prone to developing "wiggle" because of gaps behind the barrel loop, which were addressed by tightening the forend iron or, in severe cases, by professional gunsmithing, such as welding the back of the forend slots.

a call to csm will give you a better answer.

 

The change you’re referring to happened somewhere around the 1950s. Winchester introduced a spring-loaded plunger system retained by a screw. To release the forend, you have to push that plunger in (usually with a cartridge rim or a tool) and slide the wood off.