Out of stock
SKU: 45DBF30
UPC: 815835019765
MPN: 45DBF30
The CMMG Barrel W/Bolt Kit .45 ACP - 8" RDB Black is a complete upper receiver conversion system designed for shooters who demand reliability and precision in intermediate-distance pistol-caliber rifle applications. Built for competitive shooters, home defenders, and tactical practitioners, this radial delayed blowback (RDB) system transforms the way .45 ACP performs in rifle-length platforms, delivering consistent accuracy and controllable recoil in a compact 8-inch package. The system is engineered to function reliably with standard .45 ACP ammunition while maintaining the velocity and terminal characteristics essential for real-world performance.
The barrel features a medium taper profile in 4140 chrome moly steel with a salt bath nitride finish applied inside and out—a military-grade treatment that provides superior corrosion resistance and extended service life compared to standard coatings. The 1:16 twist rate is optimized for .45 ACP bullet weights (185–230 grains), ensuring stable flight and consistent grouping at typical engagement distances. The .578-28 threaded muzzle allows integration of suppressors or compensators, while the radial delayed blowback bolt system reduces felt recoil and extends component longevity by moderating bolt velocity and spring stress. The RDB design cycles more smoothly than direct impingement or simple blowback, making follow-up shots faster and more accurate.
This kit is ideal for AR-15 or AR-platform builders who are converting to pistol-caliber capability or upgrading from 9mm systems. Installation requires an enlarged ejection port to ensure reliable function—a standard modification on most dedicated PCC (pistol caliber carbine) receivers. The 8-inch barrel length balances muzzle velocity (approximately 900–950 FPS with standard loads) with maneuverability in confined spaces, making it suitable for home defense, competition, or tactical training. Verify receiver compatibility before purchase, as the RDB bolt has specific timing requirements and is not compatible with standard .45 ACP direct blowback bolts.
WARNING ⚠️ You must be 18 or older to purchase shotgun or rifle ammunition and 21 or older to purchase handgun ammunition and firearms. Please reference our requirements for ammunition orders to "restricted" states HERE. Always make sure you use the correct ammunition for your firearms. Ammo cannot be shipped to a PO Box. Please reference state & local laws before making a firearm or ammunition purchase.
