30 caliber = .308 of an inch = 7.62mm
The Universal company did make a civilian version of the M1 Carbine. Not all of the Universals use the same parts as the military issue M1 carbine. Please note this is caliber .30 Carbine, and not the 30-06 caliber of the M1 Garand rifle.
You can only use .30 carbine ammo or the European designation 7.62X33 ammo
what is a m1 carbine worth
Behind the rear sights on the receiver.
Around 300 yards.
Name of maker or sub contractor
200-360 or so
$300 see ebay
Plainfield carbines were a civilian version of the miltary carbine. Value is low, about $200.
What ever the buyer is willing to pay
look under the rear sight for MFG. and sn#