The book covers quite a bit of ground, both regarding competition pistols and rifles. Here's a very basic syopsis of the material that has to do with tuning Mosins (minus the trigger tuning stuff-I'm not that sure we should encourage too much of that for safety reasons):
He starts by going through things you need to check when choosing a rifle-sharp rifling, lack of pitting, muzzle and throat damage, and also straightness of the barrel which he advocated checking with barrel gauges.
He also emphasizes that lack of warping in the stock is important, and advocates finding a walnut stock if you are able to (because of its stability and resistance to warping).
He then goes into fitting the barrel to the barrel channel, saying that either free-floating or free-float with a barrel wrap work well, but that float/barrel wrap "has been more widely disseminated to the public and is better known".
He seems to think free float/wrap is the more reliable method, though, as it's more effective when the barrel starts to heat, and also if the forestock gets a minor warp at some time. He says there should be 1.5mm of clearance between the barrel and forestock/handguard, and says the endcap should be filed back on the edges if it contacts the barrel (shown in this illustration):
He says that if there's room in the channel for the barrel but a fit problem/warp makes it "unilaterally contact" the wood, that the problem can be addressed through the use of shims in the receiver/tang area as shown in this illustration (different of these areas for different fit issues):
He emphasizes that the areas shown in the following illustration should have complete, even contact between the action and the stock, and even advocates the use of red lead to check. He says the tang area is especially important:
And goes on to say that the shaded areas in this illustration should
not be hit by the action, and should have a layer of wood removed if they do (and also that the receiver screws shouldn't slam into the walls of their holes):
Per the following illustration, he says the top of the magazine should have 1 to 3mm of clearance from the bottom of the action, and that the side edges of the magazine should have 1 to 1.5mm of clearance from the stock:
