Springfield Armory
Yes
Stevens.
Remington
Unknown.
Take the rifle to a gun shop so they can figure out what make, model and caliber rifle you have. There is no 84 caliber long rifle.
H&a
The .950 JD Jones is the largest sporting rifle caliber made.
They were made in several calibers- will be marked on the barrel.
WHICH rifle? There is more than one type made in this caliber.
The REAL ptrs41 was a gas operated semi auto antitank rifle first made in 1938, and was approximately .55 caliber.
Marlin
You will have to me more specific. Do you mean any rifle that fires a 30 caliber projectile or 30/06 or 308?