The AR-STONER AR-15 Bolt Carrier Group in 45 ACP is ready to drop into your AR-15 upper receiver build. This universal, ramped, 45 ACP bolt accepts both Glock and Colt style magazines. No matter if you are building a dedicated 45 ACP AR-15 or modifying your current setup this affordable and reliable part is a must have. FeaturesMachined from 8620 Steel.QPQ Black Nitride Finish.Compatible with both GLOCK and Colt Magazines.Ramped bolt for a standard AR-15 hammer.Features removable weight.