Cryogenic Treatment of Gun Barrels

Cryogenic Treatment of Gun Barrels for Shotguns, Rifles and Handguns


Gun barrels are bored, reamed and machined. They are made from forgings and castings that cool at different rates, which introduces residual stresses in the metal. If these stresses are not relieved, the gun barrel may deform in ways that affect the accuracy of the firearm. Whether it is with shotguns, rifles or handguns, gun barrels with residual stress may also experience greater friction, heat, and wear – the enemies of mechanical parts. Barrels like this are also more difficult to clean and can have a shorter life.  

The  cryogenic treatment of gun barrels is a one-time, permanent way to eliminate residual stresses. First, liquid nitrogen is used to reduce the temperature of the gun barrel to -300° F. The barrel is then kept at this cryogenic temperature for 24 hours. As carbon particles precipitate, carbides form a lattice structure and fill microscopic voids. This produces a denser, smoother surface that reduces friction, heat, and wear. The increased wear resistance makes the gun easier to clean, too.

Gun barrels that are cryogenically treated also exhibit increased velocity of approximately 50 to 60 feet per second (fps). That is important because bullets that travel at a faster rate have a flatter trajectory with less bullet drop, which makes it easier for a shooter to hit a distant target.  Whether the bullet is a full metal jacket, hollow point, or soft nose, shooters also like how these faster projectiles provide deeper penetration and expansion. Muzzle velocity matters for birdshot, buckshot, and shotgun slugs, too.

How Cryogenic Treatment Improves Accuracy

Unrelieved stress causes a shotgun barrel to warp with the heat of repeated firing. With shotguns, this warping affects the shot group, the spread of individual shots from a single shotshell. The tightness of this pattern or grouping is a measure of precision. The distance between the calculated center of the grouping and the intended target (displacement) is a measure of accuracy. For target shooters, pattern placements can shift dramatically with the number of shots fired and the amount of heat that is generated.

Consider the example of a competitive shooter who targets 10 or 25 sporting clays at an outdoor range. At the end of a typical 10-shot string, the pattern placement can shift as much as six inches. Over 25 shots, pattern placement may shift up to 12 inches. That is why many shotgun manufacturers are now using cryogenic barrel treatment to reduce the stresses that cause this temperature-induced warping. With cryogenic treatment, shot groupings can shift by less than 1” for improved accuracy.

Cryogenic treatment is not just for shotguns either. This stress-relieving process is used for rifles like the AR-15, which can fire many rounds in quick succession. Cryogenic treatment is also used with bolt-action rifles like the Mauser M 98. These hunting rifles are designed to fire far fewer rounds than the AR-15, but barrel heating can still induce warping and affect accuracy. With handguns, cryogenic treatment can reduce barrel deformation caused by firing numerous rounds during target practice.         

Cryogenic Treatment for Gun Barrels from Nitrofreeze®

Would you like increased wear resistance for easier firearms cleaning? Maybe you are interested in reduced friction, heat and wear for a longer barrel life instead. By eliminating residual stresses in a way that produces a homogenously stabilized barrel, cryogenic treatment increases velocity and promotes firearms accuracy. At 50 to 60 fps, the velocity gains are significant. With shotguns, cryogenic treatment can reduce shifts of 10” to 12” to less than 1” (0.75”). 

Nitrofreeze® of Worcester, Massachusetts provides cryogenic treatment services for gun barrels and is trusted by state and local law enforcement agencies, hunters, and target shooters. Our projects include cryogenically treating 19 Remington 700 Light Tactical Rifles (LTR) for the Main State Police. Recently, we cryogenically treated an AR-15 gun barrel for a gun owner. For pricing and additional information, contact Nitrofreeze® at the phone number and email listed below.  

(508) 459-7447 x109 |