The Multi-Caliber modularity of the MDRX is what sets it years ahead of the competition. Caliber conversions can be done with minimal tools and in less than a few minutes. The Desert Tech MDRX Conversion Kit comes with everything you need to switch your MDR or MDRX rifle from one caliber to another. All .300 BLK” .308win and 6.5CM MDRX Conversion kits come with Desert Tech’s proprietary Ratchet Compensator installed! The Ratchet Compensator has been designed specifically for each caliber to maximize performance for your MDRX and any other brand rifle. The Ratchet Compensator reduces recoil while giving better muzzle control and nearly eliminating all barrel rise. MDRX Conversion Kits are available in multiple calibers” barrel lengths and in forward or side eject configurations.