CRYO UPDATE

By Scott E. Mayer

Associate Technical Editor

The previous article on cryogenic barrel treatment (January 1999, p. 46) was intended to be the “last word” on the subject, but the calls and letters we received suggest that many members were still confused and that our results gave some the impression that the process doesn't work. If it doesn't work, why then do top shooters such as Frank Hoppe, who runs trap shooting clinics and is captain of the 1999 All-American Trap Shooting Team; Bob Schanen, who's earned the President's 100 and Distinguished Rifleman's badges; and Bill Shehane, several-time IBS 1,000-yd. world record holder and 1997 IBS "Shooter of the Year" use the process?

I asked these shooters, “How does cryogenically treating your barrels contribute to your success?” Hoppe said cryo-treating, “ … keeps shotgun barrels from shifting around…” and thus eliminates that factor from any “mystery misses” in trap shooting. Schanen says cryogenic treatment makes his guns, “... shoot more consistently” for long-range shooting, “which inspires confidence.” Schanen first thought cryo-treatment was “smoke and mirrors” until he tried it. He said that he and his gunsmith immediately noticed that cryo-treated barrels machine easier and that bores drill truer.

Readers weren't the only ones confused, either. Many companies that offer a cryogenic process wrote saying that if I had used their profile and process, I would have gotten a greater improvement in accuracy. While at the 1999 SHOT Show, I had the opportunity to talk with 300 Below, Inc. in Decatur, Illinois, about the company's process. That morning, 300 Below had been granted U.S. patent No. 5,865,913 on its process, so they challenged me to use the newly patented process in a retest.

Time constraints precluded a complete nine-gun/1,200-round retest, but I thought I could glean some usable results a different way. In the earlier test, accu-

racy from one rifle, a Westpoint Model 410 chambered in .30-'06 Sprg. shot as much as 26.3 percent worse after being cryogenically treated using a profile different from that used by 300 Below. I thought that if it could improve the accuracy of this rifle, especially after the previous treatment, there might be a story in it. A representative of 300 Below said that since his company didn't know how this barrel had been previously treated, he couldn't promise an accuracy improvement, but he accepted my counter challenge nonetheless. I sent the barrelled action to the Cryo Accurizing Division of 300 Below for cryogenic treatment. This company also has a new process called “Tri-Lax,” which involves not only the extreme temperature profile, but also subjects the barrel to sonic, high-amplitude vibrations and electromagnetic-pulse-modulated RF manipulation. In laymen's terms, that means the treatment gives the steel molecules a good shake during the process.

When I got the barrelled action back, I reassembled the gun, collected the same brands and types of ammunition used in the earlier test, and headed for the range. I then fired five consecutive, five-shot groups with each ammunition, and compared them to the groups previously fired from the gun before any cryo treatment and after the first cryo treatment of a different profile. Analyzing the results was what got our readers confused in the earlier article in which we required a 10 percent accuracy improvement at a 95 percent confidence level. Rather than using this type of statistical analysis, I opted to compare the probability that one set of groups shot better than another. This comparison was done using the Baltec 1 ballistic program written by American Rifleman Ballistics Editor, William C. Davis, Jr. When the data is entered, the program automatically computes the “T” value for the samples and reports the probability. Davis noted in Analyzing Accuracy Data (Oct. 1984, p. 38) that “A statistician would call it a 'point estimate' of that probability.”

As can be seen in the accompanying table, accuracy improved across the board. In one case, the probability is 98 percent that groups fired after 300 Below's treatment are more accurate than before. I don't know about you, but if the weatherman said there was a 98 percent chance of rain, I'd bring my umbrella. Clearly, not all cryo treatment is the same. If you're still apprehensive about the process, 300 Below offers a 100 percent satisfaction guarantee.

For more information contact: Cryo Accurizing, Div. of 300 Below, Inc.

2999 E. Parkway Dr., Decatur, IL 62526; (217) 423-3070 or 800-550-CRYO.