Yes
I assume that you are referring to 5.56mm in your question?,if so yes you can shoot this ammo in your rifle.The 5.56mm is the metric designation for the .223 Remington cartridge.
lighter bullet and more ammo can be carried as opposed to the 30/06 or 308
There are many brands of 556 ammo available. Some of the better rated ones by users include Barnes and Hornday. Both have great user ratings for hits and shots fired.
if it is a 223 cal, then yes
Yes it does, unless your barrel is stamped .223 .
Yes the mags work with both ammos. You can not tell the difference in the two by looking at them.
556
556 * 556 = 309,136
Yes. The Marlin model 556 is a bolt action shotgun. It has a detachable magazine which holds two rounds and one round in the pipe for a total of three rounds. It is able to shoot 3 inch ammunition.
556 = 55,600%
Lots of them.. the AK47 and AKM and variants, the SKS and variants, the Vz. 58, prototype variants of the HK33 which fired it were made, there's a variant of the SIG 556 which fires it, the Ruger Mini 30 fires it, there are variants of the AR15 available which fire it, etc.
70% of 556 is 389.2. Which means that 166.8 is 30% of 556.