Any benefit to Fire lapping a factory 22 barrel?
- Thread starter coyoteking
- Start date
I suspect that if fire lapping a .22LR bore worked wonders, more would be said about it. But a dearth of confirmation doesn't itself mean anything.
The thing is that when a barrel is poor, there is often little that can be done short of replacing it with a better one. Hand lapping can improve things. But since it is a skill that is an part art and part science it may not be an effective DIY solution. While there are a few individual examples from every manufacturer mentioned that may shoot very well,it's worth keeping in mind that the mass-produced rifles such as those generally do not produce outstanding accuracy at the best of times.
The thing is that when a barrel is poor, there is often little that can be done short of replacing it with a better one. Hand lapping can improve things. But since it is a skill that is an part art and part science it may not be an effective DIY solution. While there are a few individual examples from every manufacturer mentioned that may shoot very well,it's worth keeping in mind that the mass-produced rifles such as those generally do not produce outstanding accuracy at the best of times.
I had good results with an S&W M&P 22 that fouled heavily and was hard-pressed to put ten out of ten shots into the 8-ring or better of a B-8 bullseye. I couldn't find lapping compound of a suitable grit, so I got some 400 grit lapping grit from Lee Valley and mixed some with grease to mix my own compound.
I would be hesitant to try it on a barrel that shot OK. As it was, the gun I tried it on was so innacurate that I felt I had nothing to lose.
I would be hesitant to try it on a barrel that shot OK. As it was, the gun I tried it on was so innacurate that I felt I had nothing to lose.
CZ doesn't hand lap their rimfire barrels. Hand lapping is time consuming and costly. The CZ website says only that they are lapped.
CZ barrels are not *hand* lapped, they are mechanically lapped. Their methodology is unknown, but is likely similar to what Shultz & Larson does. As can be seen in the following screenshots, a long lap is cast, and four barrels at a time are set up in a lapping machine. The operator presses *start* and walks away while the machine runs for "X" number of cycles. It is unclear if the barrels have been rifled at this point, or if this a post honing, pre rifling operation. No production rifle maker is taking the time to individually hand lap barrels, and CZ accuracy is literally "Hit or Miss", they put out quite a few mediocre to downright terrible barrels. But hey, when they're good, they're good.
Back to the topic of fire lapping, haven't done it. Did a little reading on it, it may help in some cases but seems easy to over-do it. If the rifle in question doesn't shoot, no real harm in trying it since the barrel is a tomato stake otherwise, can't make crap any browner. It really depends on what is wrong with the barrel in the first place, fire lapping wont cure major faults, the bullet is small so it'll just follow the irregularities compared to a long lap that will actually work to straighten the bore out.
I’m thinking of trying it as a last resort. If it doesn’t work I guess I’ll phone customer service to see what a new barrel will cost.
