What is a 'printed action' 'trued action'?

C

cath8r

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By reading the term on precision rifle sites, I gather It means that an action is square on every plane. I could see how this would be important.
Could someone enlighten me if I'm on the right track here?

Also, would a factory Remington Varminter be off and not a be a 'shooter' because it didn't have its action trued at the factory? (probably a dumb ?, just trying to make sense of it all).
 
Blue Printed or Trued action has had the face machined to be 100% true so when it mates to the barrel everything is flush together. This also includes the outside face of the bolt, at least mine was done in the process.

My information is that maybe 1:100 Remington actions come from the factory not needing and work done to them (this from a very competent gunsmith).
 
The factory action will be a "shooter". But perhaps not as good a shooter as it could be. But remember that a factory barrel is screwed into the front of that action.

Now it's entirely possible that the factory action you get will be perfect in all respects. It would be an unlikely accident; but it is possible. Factory actions are built to a certain tolerance on factory production machinery. All "blue printing" does is remove the tolerance to whatever extent is possible.

Making the action true will produce a small accuracy improvement, if everything else is up to the task.
 
Thank you.
Who in Ontario or Canada would true an action competently?
I live South of Windsor ON and we really don't have much in the way of gunsmiths that I know of.
 
Do a net search on "action blueprinting"

It is a process of ensuring that the bolt face is perfectly perpendicular to the axis of the bore, ensuring the back of the bolt lugs are contacting the action body evenly and ensuring the firing pin opening is contacting the center of the primer.

Asymmetrical resistance to recoil will result in the cartridge being forced off-center. Remember that a difference of a hundredth of a degree on the action will be multiplied at 300-600 yards.

Few if any factory actions are not crooked in some form. Sometimes bolt designs with many lugs (Weatherby for instance) are some of the worst and most difficult to true.

In the precision shooter's hunt to eliminate variables, using a custom action or having a factory action blueprinted is considered by many to be an essential element of consistent accuracy.
 
cath8r said:
Thank you.
Who in Ontario or Canada would true an action competently?
I live South of Windsor ON and we really don't have much in the way of gunsmiths that I know of.
Click to expand...
There are quite a few actually in Ontario that can do the job.
One of the better guy outfits is Milcun marksmanship complex.
Don't have Keith's number offhand, but if you google it you will get contact info.
Cat
 
Presently I true almost every 700 action I rebarrel. The guys I am doing work for want the most they can get in accuracy and it is not not that costly when you are barreling it anyway...

Although I just barreled a 700 today where the locking lug recesses and the lock lugs were as good as they could be... and the threads were hardly off ... it must have been one of those 1 in 100 rifles... and a 300 Mag. to boot...
 
The biggest controller of accuracy in a rifle is the barrel and how the bullet/ammo reacts to it. EVERYTHING else in the rifle helps you extract that accuracy potential.

The action's job is to control the pressure of firing and how the case reacts to that pressure (stretching/bulging). Remember that the only area an action SHOULD touch is the base of the case and the extractor groove. The rest of the case should be in the barrel/chamber.

Properly sized brass WILL NOT MOVE AROUND/CANNOT MOVE AROUND in the chamber. The only place it can go is backwards.

The benefits of truing any front locking solid bolt action is to ensure that higher pressures used can be contained without excessive growth in the brass. High lug contact ensures the bolt face cannot bend under firing pressure.

I have shot a few 'sloppy' Rems that were very accurate BUT the brass was allowed to grow excessively. Truing/ensuring proper lug engagement would have allowed for a tighter chamber/action fit so that this growth would have been reduced/eliminated. It wouldn't have made the rifle shoot anymore accurately.

Until you are after short range BR type accuracy and/or plan on running magnum+ pressures, money spent on the barrel will give you the largest dividends to accuracy.

That and proper loading with accurate bullets. And bedding. And proper scope setup. And trigger. And stock shape, rest and shot tracking. Even cutting a new crown.

I would strongly recommend that you do not try and 'blue print' a factory action AND the orig factory pipe. It is a huge waste of money and really isn't going to change much of anything.

Proper bedding would be a much larger benefit.

If there is poor or uneven lug engagement, improving this is a good thing but blue printing really makes its presence felt when you put on a new barrel so that LARGER threads can be cut.

Jerry
 
mysticplayer said:
If there is poor or uneven lug engagement, improving this is a good thing but blue printing really makes its presence felt when you put on a new barrel so that LARGER threads can be cut.

Jerry
Click to expand...

Actually the amount "larger" can be almost minuscule up to quite large... the size is not as important as being true to the bolt race...
 
I've read that action truing is not an issue with a Savage rifle because the bolt head "floats" a bit on its connecting pin and self aligns as a result.

True?
 
762shooter said:
I've read that action truing is not an issue with a Savage rifle because the bolt head "floats" a bit on its connecting pin and self aligns as a result.

True?
Click to expand...

False. It is certainly not an intended result in any case. On most Savage actions, the amount of available float is not sufficient to compensate for the errors in the receiver. The bolt head fits too closely in the bolt body. In fact, there is more "float available via the sloppy fit of the bolt body in the receiver. When I made to replacement bolt for my 40X, I has originally intended to make the bolt head float. Ultimately, I elected to make the bolt head a close fit in the body and let the boddy do the aligning. I did it this way because I felt that it was a better system.
It is also a myth that the barrel nut does anything for alignment. A vee thread, such as that used on the Savage and most other actions, will center itself under load. Whether that loading comes from a barrel nut or a barrel shoulder is immaterial. In the end I have no doubt that the Savage actions would benefit the same amount from remedial work as any other action of similar quality.
The one really big advantage (in my view anyway) to the Savage system is that the contact between the striker and the sear has no effect on the attitude of the bolt. Regards, Bill.
 
Leeper, you have certainly seen and worked on alot more actions then me so I only say this based on my limited experience.

In ALL my Savage and Stevens, the lug contact is very high ie near 90+% You can see that they are wearing smoothly and evenly. To me, that suggests that the action is already true or that the wiggle offered by the bolt head is sufficient to make contact near perfect.

As for the barrel nut install, what you say is correct except most can index their chamber and bolt face during the headspace process with their headspace guage. That will help align things better. The slop in the threading allows the barrel to maintain this alignment ie there is a bit of 'give' in the thread for alignment.

As long as the chamber is cut true and the headspace guage is solid and square, you can get a near perfect fit despite the normal manf tolerance in a factory action.

This has been proven to me by shooting at elevated pressures with no significant case growth and maintenance of concentricity/squareness of the case.

There may be a bit of alignment issues but the 'slop' allowed in the style of action takes care of it very very well.

Pretty hard to argue with factory actions that can shoot in the 1's and 2's, with the occasional group in the 0's, with a simple rebarrel.

Jerry
 
rpollock said:
If you say so!
Click to expand...

I think you will have alot of fun on this site.

Enjoy...

Jerry:welcome:

PS here is a group shot recently with my new pac nor barreled 223 at 200yds. Yep, untuned factory stevens 200 action. I think that qualifies as a group in the 0's. Math was off. Should have been 0.056" for a 0.028min group. Yes, it is only 3 rds but I was working up loads and only had 3rds of that load. Close enough.

223pacnor.jpg
 
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<sighs>
Ja, a 100 round group would have been better.
But we don't have that, do we?

The fact is, even a 5 shot group is very near statistical insignificance.
 
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