Is my Parker safe to shoot 2 3/4 12 gauge shells?

[Adam Auksztulewicz]

Hello and thank you for allowing me to join your forum! I just was given this 12 gauge parker side by side and all I know is information that I found here on this website. It has Titanic steel barrels, 30 inches, weight 4.9 but I'm not sure how to find out the chamber length. I plan on shooting it tomorrow morning so I don't want to blow it up, or me up in the process if it's designed for shooting 2.5 inch shells versus 2 3/4 shells... Was planning on buying some low recoil low power 2 3/4 shells on my way to the range tomorrow morning. Here are some pics I just took of it, any information would be greatly appreciated!
Thank you!