Stalcraft Wiki: SR-3M

"The SR-3M is a high-skill, high-reward ambush weapon that benefits from the superior armor penetration of the 9x39mm caliber. This allows it to effectively challenge heavily armored targets that might otherwise shrug off 9mm fire at close range. While it can be equipped with a 30-round extended magazine to mitigate its base capacity issues, its high vertical recoil and aggressive damage falloff past 40 meters make it difficult to use in open environments. It excels in the 0m to 12m envelope where its high alpha damage and penetration can quickly overwhelm an opponent."