Blueprinting an action

Like all mass produced machiery, all rifle actions have a range of spec, +/- whatever, and blueprinting will ensure that all these specs are within the minimum tolerances. Actions can vary tremendously, at least the run of the mill ones (Rem, Win, Ruger, Sako, Tikka, Mauser, etc). The specialty actions are usually held to a tighter tolerance to begin with, so less problems. Unless abused, rifles don't go "out of tolerance" from shooting. - dan
 
I think blueprinting is a term most correctly used with building engines and actually is incorrect terminology as far as actions are concerned. Blueprinting would mean you rebuild the engine with very close tolerances to what the original engine specifications are.... following the factory blueprint of the engine.

Trueing an action or checking an action on how true everything is to the bolt race is what is done with actions. Since making a correction involves removing metal the factory specs or blueprint changes.

Often when a new custom barrel is going to be installed, the owner wants to have the action checked and possibly trued in order to obtain more accuracy.
 
Good points Dennis. To answer the other question, who has generally tighter tolerances, I have taken measurements off every action I've owned (about 200 or so), and I would say that GENERALLY; Sako and Savage are the best from the factory. Remington and Winchester run hot and cold, you'll get a range of good ones, and then some pretty awful stuff (different inspectors or plants maybe), the Rugers are consistant, if not great. FWIW - dan
 
The reason for 'blue printing' (more accurately truing) an action is to align the bolt face with the bore and chamber of the barrel as true as possible while have the bolt lugs seat squarely and evenly in the receiver. The front of the receiver is also squared up so that the barrel 'seats' squarely when tightened on the action.

I am glad to hear that the Savage actions are machined well. Certainly is reflected in its performance dispite the pedestrian pricing.

This is the only mass produced action with a floating bolt head. The bolt head is a separate piece from the bolt body and can move slightly during lock up. This help ensure that the lugs are well seated in the receiver even when the receiver is not exactly true with the bolt raceway.

Kind of neat way to put some slop where it is needed to tighten things up.

Also, with the use of the barrel nut, you can true up a chamber and bolt without resorting to maching the threads on the action. There is usually slight slop as with most threaded items, to allow for the barrel to be locked in place square with the chambered guage or case.

I might be describing the mechanics a bit wrong but the point is that it kind of self aligns itself. Works pretty good.

Jerry
 
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