By introducing a bolt action barrel blank, we've expanded the possibilities for adapting your preferred caliber and accommodating various actions. Our bolt action barrels come In a range of calibers, lengths, profiles and rifling twist rates. Your bolt action barrel will arrive ready for threading and chamberings by your chosen gunsmith. It's important to note that while proof Research's barrel blanks can be customized with different chambers, performance metrics like accuracy, muzzle velocity and bullet stability cannot be guaranteed. This especially applies to wildcat cartridges without standardized chambers, designs or pressure specifications. While proof Research's barrels are designed for safe operation with most established cartridges and within SAAMI and CIP pressure limits, caution is advised for unique rifle builds. If you have questions about safety or the potential performance of your intended rifle assembly, please contact our customer service department.