Originally Posted By: Lloyd3
They might be a little longer. All I know is that I cannot use them in my circa 1920 Model 12 in 16 (I tried, not even close). That is an RST only gun.

Lloyd, would that gun be a 2 9/16" chamber? I have a 1914 M12 16ga and it's a 2 9/16" chambered gun. I use 2 1/2" Spredr loads.
Of course it's full choke.