For clarification: I do not manufacture airguns, but do make and modify parts and "build" guns. Same as I "build" military vehicles for a living, but I don't produce the armor plate, etc, etc. So, "build" seems the correct term for what I do. Also, I have used the term "lap" generically, incorrectly, what have you, in terms of the use of JB bore paste. The gunsmith who mentored me always refered to "polishing" with JB as "finish lapping" and I have used the term "lap" since. But, I do understand what "lapping' is and I do use abrasive lapping compounds on barrels and have yet to "ruin" a bore. I do use a cordless drill with JB and Kroil. I do also have guides and rods specific to the task.
It is very evident that you are very skilled, knowledgable, and shoot high end guns. I also understand that many barrel makers "lap" before a barrel leaves the factory. Last I checked, crosman, green mountain, and TJ's do not lap their barrels. They show up rough and in need of help. Those barrels get started at 280 grit and worked up to JB by hand, by me. I never said I was running lapping compound thru a steyr. I "build" marauders for long range hunting. I am far from an expert, but do work hard to make accurate airguns. Maybe not what you consider accurate, but turning a $500 airgun into an MOA hunting rig out to 100 yards is an accomplishment to me. Achived by working over a raw barrel that was not lapped at the factory. Even the hammer forged TJ barrels are blanks that need machined and lapped! I did not claim and will not claim to be a "lapping" artist like those that work for some of the fine barrel makers, but thru a process of lapping, testing, lapping, testing, I have gotten pretty good at making low quality barrels shoot pretty dang good. FWIW, I have went thru as many as 9 barrels in search of a "good one" for one rifle.
I apologize for any confusion due to my terminology and I also respect your input as you surely know what you are talking about and I would agree with you if it weren't for the fact that the barrels I use are not lapped. None the less, I understand your skepticism 110%. Though my title is not Mechanical Engineer, I have a very strong foundation in the field, but metallurgy is more of my strength. I can assure you that though my choice in airguns is at the lower end of the scale, it is not from a lack of anything. It is based on a desire to improve upon a platform that has proven very useful for my needs. It is a hobby within a hobby.
Based on your response, I assume that your intentions were to show that I am full of it? I am not reinventing anything. I am doing what is not done at the factory with the barrels that I am using. And, as hard as you might find it to believe, I have used lapping compound on LW, BSA, and CZ with good result. Those barrels weren't lapped without reason. The notion that no one is capable of properly lapping a bore is ridiculous!! Again, I make no claim to being an expert. I have been very fortunate to learn from some very good smiths. Maybe I am doing everything wrong, but I am getting the results I am after and I guess I could care less past that.