He should have pointed out that the addition of a heat-shrunk threaded adapter to the barrel could possibly constrict the bore, creating an overpressure condition in the barrel. Lead slugs should be cast into and driven out of the barrel, before and after adding the threaded adapter. If the micrometer indicates that the barrel has been constricted, that area of the barrel must be "lapped" (with another cast lead "slug", and an abrasive paste.
There are no better books on this subject. I have looked high and low for such books, for many years now. I would not, however, pick a Mini-14 as a rifle to suppress. The remounting of the front sight and threading of the barrel are serious problems for the silencer maker. Those problems do not exist if you just use the AR-15 rifle as a basis for your suppressed 223 desires.
An author of unquestionable knowledge whose fear, if any, does not show. He's honest open and gives those looking for info a place to find it. There is so much fear today from the gov't impunity to it's responsibility, it's nice to know there are still one or two who don't run and hide every time they are asked to show their knowledge. The Gov't has the 2nd Admendment on the run as they bend and hide behind their cowardess. Support the NRA and your 2nd Admendment rights....or you won't have any, any more.
Poorly written with difficult to follow instructions that involve poor techniques and designs. Possession of items described as parts in this book and/or making items described within without first obtaining permission from the Federal and State governments are felony crimes punishable by $10,000+ fines and 10+ years in prison. You can ask the author he spent years in prison himself. There are better books available if the study of this topic interests you.
Ciener Firearms makes a .22lr conversion unit for the mini-14, for the AR15 and for the AK type rifles. You'd be well advised to forget the Mini-14 and just use an AR 15 for your silenced fighting/survival rifle. Whichever rifle you choose, use the .22lr unit (first) to testfire the silencer after you make and mount it, or use very feeble 223 reloads, and look in the barrel and silencer after each shot, to see if anything is blocking the bore or the passageway thru the silencer. Full powered ammo is highly likely to destroy the silencer if anything is amiss, while the feeble stuff will not do so.