Greg and Keith...I agree that notching the barrel is a waste of time, isn't at all necessary, and weakens the lug of the tang. I don't do it anymore, but mentioned it as a clearance option in answering the thread's question.
As far as taking the barrel out, we've talked about this before. On all my guns, whether pinned or with slides, I take the barrel out every time I shoot it, to clean it thoroughly. Without pumping cold water under the pressure of a tight fitting cleaning patch on a jagged rod, I am unable to see how ALL of the fouling can be removed from the breech area. I would be obliged to learn how I can clean my rifle without using this flushing system, as it is somewhat time consuming, and with a pinned barrel, does loosen the pins in the wood.
I just had one of my rifles from 1980 in the shop for a new ramrod, and while it was here, I cleaned the bore. When I got the patch stuck half way down, I realized too late that although the outside of the gun looked well maintained, the bore was in tough shape. The barrel had never been off, and the pins were rusted in - the very devil to remove without damaging the surrounding wood. The underside of the barrel, at the muzzle and breech was seriously corroded with scaled rust. I was unable to get me jag to back out, so I pushed it with huge effort, and the use of a mallet down on the breech. I unscrewed the stainless rod, removed the nipple from the drum, poured in as much 4Fg as I could, replaced the nipple, warned the household to plug their ears, and fired it out into the stump on which my anvil sits. Now I cleaned the rifle in cold water with my flushing/pumping system, and I got a lot of red fouling - rust - but finally, I got it cleaned out, scrubbed with ScotchBrite pads, then 0000 Steel Wool, and oiled it up. The owner cleaned his rifle while the barrrel was still in the rifle, but never got past the drum's hole, I guess, because that last 1/4" was really rusted up. If that's what to expect when cleaning without removing the barrel, I don't want any part of it.
So, at the risk of stealing this great thread, pls. enlighten me.