There is an ancient axiom which says, If the shoe fits, wear it.
Your post appears to pretty well slam my firelapping method, which you did not try. What you did was take advise from other ignorant people and proceed in their ignorance. That guarantees poor results. In other words I'm not letting anyone put such a shoe on me or my firelapping method. Furthermore, I think it would be good for anyone questioning whether to firelap to first read your results of not doing it right. With that I'll try to explain what I believe was your problem, and my explaination is with many thousands of customer reports behind me, None of them bad. Though many have had what I believe was your problem and I warn very carefully about it in my extensive instructions.
I believe your lack of results were due to very good fortune for you, in that you were getting leading which stopped the abrasive action necessary to slick up the barrel. If you had not been getting leading you postiviely would have been crying about ruining the barrel, as the 220 grit would have removed about 3 inches of the rifling origin, or throat.
Let me strongly recommend that anyone interested in firelapping purchase the stuff from LBT. I developed the process and have what works without fail. There have been many would be 'wise men' who make recommendations of various slugging and lapping methods, who actually don't have a good base of proven results to substantiate what they are saying. My costs are very low per gun, so going with anything else will almost certainly cost you more than simply getting the proper compound and instructions. Understand that I don't sell firelapping kits to make money but do it at a price that just covers expenses with a bit extra to compensate for hours of phone time to anyone who runs into snags. My whole reason for selling lap kits and teaching the world how to do it right is so that optimum cast bullet performance is possible. Without perfect bores perfect performance cannot be obtained. Firelapping with my method and material, and slugging with my push through slugs are the only way I know of which will improve any barrel, even rough pitted ones, and make them shoot respectably, while also improving premium custom gun barrels, ALWAYS!
About optimum bore configuration. Your hand lapping CANNOT produce it. For best performance with both cast and jacketed, the needs to be slightly tapered, small at the muzzle, and free of jerkyness as felt by an LBT push through slug. It doesn't have to be free of all tooling marks, but only smoothed enough so the bullet slides with perfectly smooth and consistent force. Secondly, and most important for cast is that the throat, into the rifling lands needs to be smoothed so that the rifling land origins are rounded and tapered a little. This does wonders in controling the stripping of rifling engagement on the bullet, and also dramatically improves hydrolic lubrication pressure during the critical takeoff of the bullet.
Round balls, and for goodness sake fishing sinkers which cost 2 or 3 times what my pushthrough slugs do, will not give you a feel or accurate measurement of a rifled bore.. This in part because they have to be driven or tapped through the barrel and with every tap they swell to the barrels size at that position. LBT push through slugs take one bump to get started and are then pushed through with moderate to light hand pressure giving a very precise feel of what a bullet feels. When a bore is lapped perfectly they take the light bump to get started then give a consistent smooth resistence full length of the bore right up till they fall out of the muzzle. There is NO OTHER method for a layman, or professional barrel maker to measure with equal precision.
About hand lapping. It is impossible to hand lap to a barrel with the perfect configuration obtained by fire lapping. Handlapping ALWAYS leaves both ends of the barrel a bit unfinished, with the most crucial end being the throat, in most cases. Also, there are very few people capable of doing it right, this speaking of mechanical skills, but also physical strength. Doing it right will raise a good sweat on a strong mans brow, and leave him with sore muscles, if extensive lapping is needed. Firelapping can be done, with perfect precision by anone capable of handloading ammo and firing the gun.