I have NO IDEA where you heard that or where you read it.
I’m guessing you didn’t since he never has been.
Listen to the “inspiration speech” in Rocky Balboa and you’ll know what he’s all about.
I seem to remember when FReeRepublic was young Stallone had made some gun grabber statements and we made fun of him for it as his movies are full of guns. He even admitted he owned guns and had his own home pistol range but he was concerned about “plebs” owning guns.