From what I've read the crogenic rifle barrels have the same basic problem as the camshaft, is it worth it? Having looked at some of the scientific analysis tests I've come to the conclusion that it does not increase accuracy enough to warrant the cost. Some have said it has no impact on accuracy, conflicting test data at best. It may depend on the individual rifle barrel in question. I know all tires are not created equal, no doubt that holds true for barrels as well. If I'm stakeing my life on my rifle barrel, well heck yeah I want it treated!
It does make the barrel "last longer". How much longer? The numbers suggest you won't live long enough to fire enough rounds through the barrel to make any difference in your lifetime! But your Grandson might appreciate it.
I think the benefits of cryogen treatment in general are simply not worth the investment to the average race guy. Let alone the average street car guy! I'll leave it for the deep pocket guys where "cost is no object". Nothing wrong with it, won't hurt, if you have an unlimited budget, go for it!