A few months ago, I bought a used Ruger 77/22 chambered in .22 Magnum. I was quite disappointed in the accuracy, and I had decided to sell it again.
Then I was referred to a web page about replacement 77/22 barrels, where I learned that the barrel does not screw into the receiver as is normally the case with a centerfire bolt-action rifle. Instead, it is a slip fit, clamped in place by a couple of retaining screws. Right away, I realized I could have a loose fit here, or the screws could even be loose.
(Note that this same design is used on the Ruger 10/22, which may also be susceptible to this problem.)
I removed the barreled action from the stock and loosened the retaining screws. They didn’t seem as tight as they should have been, but they weren’t exactly loose. I slipped the barrel out of the receiver and found all kinds of crud around the barrel shank — an obvious sign that there was a gap. I cleaned it up and found that it was very loose. With the retaining screws off, I could shake the receiver and hear the barrel rattle. With the receiver clamped down to the bench, the muzzle end of the barrel could move freely more than an eighth of an inch (that’s more than 20 MOA). This was clearly the cause of the gun’s accuracy problem.
After looking and asking around online, the best solution seemed to be Loctite. Loctite makes a series of retaining compound products for “slip fitting cylindrical components that are not threaded.” Loctite 620 is the high temperature variety. It is green (even though it comes in a red bottle). The one disadvantage of using Loctite is that I will not be able to remove the barrel easily in the future. If I had another barrel, switching between calibers would not be possible. If I sell the rifle, I will want to inform the buyer what has been done.
A couple days later, I had a bottle and I used it. I let it set up for two and a half days, and then I put the rifle back together and took it to the range. Everything I shot grouped much better. I will have to do some more testing, but after firing five-round groups of everything I had, the 33 grain Remington AccuTip was the most accurate, giving me a sub-MOA group. I am very happy with the rifle’s accuracy now, and I look forward to shooting it more in the future.