Each Ruger American Rimfire® rifle includes two interchangeable stock modules that provide comb height options for scope or iron sight use (excludes wood stock models). Standard models come with long length of pull modules, while compact models come with short length of pull modules. By simply removing the rear sling swivel stud, stock modules can be changed in seconds. All four stock modules are completely interchangeable across all models and are available at ShopRuger.com. Models chambered in .22 LR feature the patented, detachable, flush-mounted 10/22® BX-1 10-round rotary magazine and accept all 10/22® magazines, including the BX-25®, BX-25®x2 and BX-15®. Models chambered in .22 Magnum and .17 HMR use the detachable, flush-mounted JMX-1 9-round rotary magazine. Easy-to-use 10/22®-style extended magazine release provides smooth, no-fuss removal of flush-mounted magazine.