Cryogenic Treatment for Gun Barrels

Cryogenic Treatment for Gun Barrels: Four Firearms Experiments


Cryogenic treatment for gun barrels reduces residual stresses in the metal for faster velocity and tighter, more consistent groupings. This one-time, permanent treatment also increases wear resistance for easier cleaning. Several firearms manufacturers have incorporated cryogenic treatment into their production processes, and gun owners are discovering the benefits for improved barrel life and performance.  

Recently, a local gun owner named Leon Desy brought several barrels to our Worcester, Massachusetts facility for cryogenic treatment. Leon then posted before-and-after data in an on-line firearms forum and allowed Nitrofreeze® to share this information here. During a telephone interview, he provided additional details about four firearms experiments.

#1 Cryogenic Treatment for Ruger Mini-14 Ranch Rifle

Leon’s first experiment involved a Ruger® Mini-14® Ranch Rile with a 1.5” barrel chambered in 5.56 with a 1×9 RH twist. Using a Leupold 3×9 Vari scope, he reported a cold-to-hot shot drift of 6” under cold-weather conditions. Using a chronograph, he measured the velocity at 2650 feet per second (fps). The ammunition was a reloaded 68 grit (gr) HPBT Sierra Match King with 24 gr H335 and CCI® primers with a cartridge overall length (COAL) of 2.260. He used the same ammo both before and after cryo treatment.

As some gun owners know, the heat from repeated firing can cause the barrel to warp. The cause is residual stress from boring, reaming, and machining operations. The solution, cryogenic treatment, may be less well-known. Before Leon found Nitrofreeze® during a Web search, he spoke with a shop that wanted $800 to fix his $70 gun barrel with custom machining. He also tried experimenting with an adjustable gas block but could not get a good grouping. Neither option was the right solution.

With Nitrofreeze®, Leon just dropped-off his gun on the way to work and then returned for it the next day. After this affordable, reliable process, he continued his testing. First, he fired three rounds at a target and reported a 1.5” inch grouping 1” low-right. Next, he fired 20 rounds off target to really heat-up the gun barrel. Finally, he fired another three rounds at the target. At 2”, this second grouping was almost as tight as the first. Moreover, it was also 1” low-right. “I consider that a success,” Leon said.

The gain of 116 fps that Leon reported is important because it’s a 4% increase in velocity and an 8% increase in stopping power. By making the metal in the gun barrel more uniform, cryogenic treatment reduces the coefficient of friction so that there’s reduced resistance to a round as it travels through the barrel. “You get more uniform steel,” Leon explained.

#2 Cryogenic Treatment for P320 Compact with 3.9” Barrel

Leon’s next experiment was with a brand-new P320 Compact, a Sig Sauer handgun with a 3.9” barrel. He used 9 mm Winchester 115 gr bullets with an advertised speed of 1190 fps. Leon chronographed the velocity at 1030 fps before cryogenic treatment. After cryo treatment, he used the same ammo on a day with the same temperature conditions as the first. The velocity, 1100 fps, was an increase of 70 fps.

#3 Cryogenic Treatment for P320 XFive with 6” Barrel

The third experiment involved a Sig P320 XFive with a 5” barrel and the same ammunition as in the previous experiment. Before cryogenic treatment, Leon chronographed the velocity at 1070 fps, a disappointing 120 fps slower than the ammo’s advertised speed but still faster than the pre-treatment speed for the P320 Compact and its shorter barrel. After cryogenic treatment, he chronographed the velocity of bullets fired from the XFIVE at 1170 fps, just below the advertised speed of 1190 fps.

That’s when Nitrofreeze® suggested a second cryogenic treatment. With the same ammo, the twice-treated gun yielded a small but important gain. At 1200 fps, the velocity now exceeded the advertised speed for the ammunition. Compared to the pre-treatment speed, the velocity was 12% higher and the stopping power 24% greater. “It’s like shooting a magnum round,” Leon said. Satisfied with the results, he then tried another experiment.

#4 Cryogenic Treatment for AR-15 Barrels

Leon’s final experiment involved two 18” stainless steel AR-15 gun barrels chambered in .223. Both barrels were made by Wylde and had a full gas system. The first barrel had 2000+ rounds and a black finish. The second barrel was brand new and machine finished. Leon asked Nitrofreeze® to cryogenically treat both barrels so that he could compare the results.

After cryogenic treatment, Leon used the AR-15 with the new barrel, which had fired only 50 rounds previously. He started at 10 am on a day where the outdoor temperature was 32° F. For the first grouping of 10 bullets, he fired a round, recorded the speed, and ran a patch with Hoppe’s No. 9 gun bore cleaner.

The table below shows the speeds for each of the 10 rounds in this first grouping. Low, high, and average velocities are indicated.

Barrel Grouping Round Speed Notes
New 1 1 2911  
    2 2917  
    3 2911  
    4 2911  
    5 2949 High
    6 2923  
    7 2936  
    8 2879 Low
    9 2911  
    10 2930  
    Avg. 2917  

Then, for every 10 rounds that he fired, Leon recorded the low, high, and average velocity. Between each of these groupings, he ran a patch down the barrel. The table below shows results for groupings (Gp) 2 to 15.

Barrel Gp Low High Avg. Notes
New 2 2917 2982 2943 Temperature was 32° F
  3 2917 2976 2952  
  4 2917 2989 2960  
  5 2879 2996 2941  
  6 2886 2956 2924  
  7 2892 2976 2925  
  8 2898 2976 2931  
  9 2892 2956 2925 Temperature was 34° F
  10 2879 2962 2928  
  11 2898 2962 2935  
  12 2911 2982 2940  
  13 2904 2976 2938  
  14 2917 3003 2952  
  15 2879 2949 2924 Temperature was° 36 F

Leon finished this part of the experiment at 1 PM. By then, he had fired 150 rounds and the outdoor temperature had risen 4° F. Then he replaced the new barrel with the broken-in barrel that had 2000+ rounds. This eliminated variables such as springs and bolts. He also used the same factory ammunition.     

This table shows the results for groupings 16 to 20. After each grouping, Leon ran a patch to clean the bore.

Barrel Grouping Low High Average
Used 16 2818 2911 2852
  17 2904 2943 2910
  18 2861 2982 2919
  19 2836 2898 2869
  20 2812 2917 2857

The test ended at 4 PM when the light began to fade. Leon had fired 200 rounds across 20 groupings. The highest speed of the day, 3003 fps, was part of grouping 14 and after at least 139 shots had been fired from the new barrel. Grouping 15 then had a high speed of 2949 fps, which matched the highest speed from the very first grouping. With the used barrel, the highest individual speed (2982 fps) and the highest average speed (2919) were both part of the middle grouping when the gun barrel was no longer cold.

Cryogenic Treatment for Gun Barrels from Nitrofreeze®

Nitrofreeze® thanks Leon Desy for sharing the results of these four firearms experiments. If you’re a gun owner who would like to like to learn more about cryogenic treatment for gun barrels, contact Nitrofreeze® at the phone number and email listed below.

(508) 459-7447 x 109 |