BEWARE I HAVE HORRIBLE CAPITALIZATION.
I Have Been Thinking About Maybe, An M1 Garand Perhaps? It Is A Semi-Automatic Rifle, It Has A Famous Ping, It Has A Bayonet Slot At The End Of The Gun (Barrel Side), It Has An En Bloc Clip With 8 Rounds, This Would Have To Be Shoved Into The Gun Using The Finger Physics.
Additional: Garand Thumb, Could Come With Gun
If They Fail To Get Their Finger Out In Time, Then Maybe Play Like A Small Grunt Sfx Or Something To Signify The Player Getting Hurt?