The Mossberg 715T is a variant of the Mossberg 702 Plinkster and is a semi auto action rifle; in addition it has been designed with the AR/M4 style stock and body, and is meant to be lighter as the name implies. The ammunition it uses is .22 caliber Long Rifle rimfire shot. It comes with a 10 round mag or 25 round mag. It is very accurate and fires very quickly.
References
Mossberg 715T 22. LR Wikipedia(Text) CC BY-SA