I don't believe I have ever used CB Longs. Do they have an effect on the 22LR chamber if used frequently? They certainly sound like a good solution to the noise issue.
Nope, but then again I've never had a problem with shooting CB shorts out of .22lr chambered firearms either.
Supposedly, the point of CB longs was that some rifles have difficultly feeding CB shorts from their magazine due to the overall shorter length vs. a long-rifle cartridge. Now, it's worth noting that it doesn't really matter in semi-automatic firearms, as they won't typically cycle with cb shorts
or longs anyway. However, there are a bunch of magazine fed bolt-action rifles on the market that would likely benefit from the easier feeding of CB longs.
Now, personally, I've got a Henry youth rifle chambered in .22lr/.22l/.22s that is fed from a tubular magazine. I love shooting CB shorts out of it, because I can fit 19 of them in the tube plus 1 in the chamber for a total of 20 rounds. With long rifle or CB long cartridges, that number is severely reduced. As an added benefit, being a lever action, it doesn't matter if I'm shooting .22lr or .22 cb short, both cycle just the same. All in all, it's one of my favorite rifles.