Complex sentence: The.222 Remington aka the Triple Deuce/Triple Two/Treble Two is a centerfire rifle cartridge introduced in 1950, and was the first commercial rimless.22 (5.56 mm) cartridge made in the United States.
Split into simpler sentences: The.222 Remington, which is also known as the Triple Deuce/Triple Two/Treble Two is a centerfire rifle cartridge. Introduced in 1950, it was the first commercial rimless.22 (5.56 mm) cartridge made in the United States.