When converting a GWACS Arms CAV-15 MKII receiver to .45 ACP this buffer is required to prevent damage to the lower receiver. Designed specifically for pistol caliber conversions. The 7 ounce weight and longer length contribute to a shorter stroke and softer recoil. The sliding insert acts as an anti bounce weight. The polyurethane bumper is designed to absorb energy for softer operation.
Will NOT work with rifle caliber uppers. Will NOT work with full length rifle stocks.