12 gram powerlet
A layer 1 device will extend a collision domain
The correct size of the bullet that fits the rifle.
By handling it
The 7mm designation is a reference to the bore size, or diameter. In decimal size it means this rifle has a barrel groove diameter of .284 inch.
There is no one answer- it depends on the rifle. They are generally less powerful than a full size battle rifle cartridge. The M16 rifle uses a 5.56mm bullet, the AK47 a 7.62mm bullet, etc.
Caliber
Are you asking about caliber or the actual size of the rifle?
Should be marked on the barrel. If not, have it examined by a gunsmith BEFORE you attempt to fire it.
depends on the rifle and the scope. Most scopes will use 1 inch rings for that type rifle.
Unknown.
Generally refers to size of projectile.