Action blueprinting as developed using Remington actions in the USA is a process often misunderstood. There are many possible ways to complete the job and each individual gunsmith will have their own methods.
The following is a short description of what is involved in our “blueprint”.
- Centre and retap mount base holes to 8 x 40 UNEF
- Ream and lap action bore to an even size end to end.
- Bore crest of action thread until true.
- Recut bolt lug seats & true action face.
- Single point thread action until thread is completely true with 16tpi full profile insert.
- Supply new, surface ground recoil lug.
- Ream inside of bolt body to clear firing pin spring.
- Drill out firing pin hole in bolt face and tap ready for bushing.
- Make & install threaded bushing.
- True bolt nose, front of bolt lugs and bolt face.
- Drill and ream new firing pin hole to 0.070”
- Convert firing pin nose to suit new hole diameter.
- Polish firing pin & install new Wolff spring.
- Bush bolt body in front of bolt handle and behind bolt lugs to be within 0.001” of action diameter.
- Fit weaker ejector plunger spring if required.
- Re-black or bead-blast action
Move bolt handle forward to correct pre-extraction cam misalignment
Convert extractor to Sako type
Is it all worth it?
If you do not already own a Remington then probably not.
Partly due to the availability but mainly because they are a simple round shape. Eccentrically shaped actions like Sako’s are a little more difficult to set up to ensure that the action bore is running true prior to rethreading and less can be done to correct bolt fit issues. Considerable investment in tooling is required for full blueprints and so it is often not cost effective to do anything other than Remingtons.
Recent blueprinting developments.
For those wishing to embark on their own blueprinting there are now good products available to aid the process. Gretan Rifles make an Action Blueprinting Jig that we have used with good success. Pacific Tool and Gauge also make useful tools like their action truing reamer.