browning A5 shot type

I have an older (1938) Belgian made A5 12 gauge. Can you shoot steel shot shells or do you need a tungsten matrix or another alloy type shot?

Browning says no, but many on the internet say yes as long as you’re not using a full choke.

To remedy this on my 1968 Belgian model, I bought a late model Japanese barrel with Invector chokes.