The R97S buttstock is 10-1/4" long with a length of pull of 13-1/4".
The only other interchangeable buttstock we have is the Youth stock # AZ15279 for around $28.00 that is 8-1/4" long with a length of pull of 11-1/4".
The Carbon 15 Model 21, 97 and 97S rifles will accept the AR15 type stocks. There is no provision for a buffer retainer. The rear of the receiver needs to be modified so the dimple in the adaptor plate of the telestock will fit. Loctite is recommended on the locking ring for the installation. With # 242 Loctite on the threads for the nut, not the receiver, turn the nut on until it is snug. When an AR15 type stock is used on a Carbon 15 the longer AR15 type bolt carrier with key part number 8448505-M4 for around $95.00 must be used with that buffer system.
If a stock is added to pistols they would then be classified as a "Short Barreled Rifle" which must be registered on a Form 1 with BATF requiring a $200.00 Tax Stamp.
For more information, please feel free to contact us at 1-800-883-6229.