It did take about 80 rounds to get back to the accuracy I had before. Is this normal ?
The Remington 541 is a fabulous factory provided rifle. For sure, .22 rimfire ammunition can and will cause a carbon ring is some instances due to the inherent properties involved with .22 rimfire ammunition.
Normally a carbon ring can form at the transition of the chamber, through the leade and then into the rifling. Over 50+ years my purpose has been involved with the use and testing of .22 rimfire rifles and handguns, mostly with the sporter guns, with the current forms of ammunition available, as that's what MOST of my customers have and deal with.
Every single .22 rimfire that I've peered through, and have run lead slugs through, have been found to have a land to groove height of from 0.0020 to 0.0025 thousandths of an inch. Now that's a tiny bit thinner that a single sheet of paper.
In all of the past and current .22 rimfire barrels that have been button rifled, the chambers are then cut with a chambering reamer, along with the throat, or leade. That reamer cuts in a clock-wise rotation and then when it passes over the lands, it will, in many cases, produce a roll-over burr on the left side of each land in the throat or leade. Being a right-hand twist at 1:16, when a lead bullet passes over that slight burr, some lead will be pealed off the bullets bearing surface, and a carbon/lead mixture can and will build up. Over time, the flame temperature behind the bullet will burn that burr off,. or it can be done with some judicious lapping done by someone who know what they need to do, and do it properly, without moving the leade forward.
I would NEVER recommend "fire lapping" of any .22 rimfire barrel. Evidence after that process has proven that fire lapping can move the leade forward as much as ¼ of an inch and that will cause a fired bullet to need to jump that much further forward to engage the rifling. If alignment to the bore has been changed, accuracy will suffer, big time.
Now, for the average plinker or recreational .22 rimfire shooter, this may not mean much, but for those of us who want "minute-of-squirrel-eye" accuracy, it's important to fill that cast iron skillet with some good chewin' on squirrels with dumplings slathered in gravy.