Rifle Action Blueprinting and Truing
GunCraft's gunsmiths have years of experience in rifle action blueprinting and are able to blueprint any type and make of action. At GunCraft we recommend action blueprinting whenever a barrel or caliber change is done. An action is only blueprinted once in its lifetime and has many benefits.
What is Action Blueprinting?
Blueprinting or truing a rifle action is when all the critical aligning surfaces of the action are machined to be square with the action center line. This ensures that all the locking faces has maximum parallel contact once the cartridge is chambered.
Benefits of Action Blueprinting
- Blueprinting improves accuracy.
- Extends case life because the case experiences a constant concentric and parallel pressure form the bolt-face on firing.
- Ensures maximum contact in lockup and no unnecessary deflection in force distribution on firing.
- Smooths action operation and lessens force needed for opening and closing the bolt.
How it's done
Blueprinting is a complex operation, see diagram below.
A. Rifle Action Body
B. Bolt
- Action center line
- Action and Bolt locking lugs
- Bolt face
When Blueprinting is done the face of the action body, where the barrel meets the action, is machined perpendicular to the action center line (1).
At the same time the action locking lugs (2) are machined to be precisely parallel to the action face.
The bolt face (3) and bolt locking lugs (2) are then simultaneously machined for perfect perpendicular alignment to the action center line (1).
Once machining is done, the bolt and action locking lugs (2) are lapped in by hand for a perfect fit.
At GunCraft we do not re-cut the action thread because the internal action tolerances are usually greater than the thread to action center line run-out. This has been proven on the range with accuracy testing. But if the run-out is greater than internal tolerances, it is a problem and the thread will be re-cut.
Examples of Blueprinting by GunCraft Gunsmiths
Before
After
