Difference truing an action makes? *UPDATE TEST RESUTLS*

Republic of Alberta

Republic of Alberta

CGN Ultra frequent flyer
Rating - 100%
25   0   0
Location
,location, location
Here is a question for some of you. Lets say you take a factory rifle, get it shooting as best as you can with loads, bedding etc.. Then take it apart and true up the receiver face, lugs and bolt lugs, and bbl shoulder, ream original bbl for correct head space then put it all together.

Will it shoot much better than before? Would there even be any difference in accuracy on say the average Remington, Savage action??

Anyone try it?
 
Last edited:
Very well might make an improvement. I suspect more likely with the Remington than with the Savage, because of the Savage's breeching system.
An improvement might result only if the areas you mentionned really needed to be adjusted. That may or may not be the case.
 
tiriaq said:
An improvement might result only if the areas you mentionned really needed to be adjusted. That may or may not be the case.
Click to expand...

Kind of what I was thinking then , if something is out of wack badly you may see a difference, if not there may be little to no difference??????


I have a Stevens that I have been shooting to get a point of reference of it's accuracy. I am going to true up the action face, maybe the locking lugs if they need it, check the recoil lug and replace if necessary, check out the nut then head space and shoot to see what I end up with. I will leave the receiver and bbl threads alone. IT is a learning exercise, so I must verify that I did not make the gun shoot worse with my hackery. I am not sure I expect it to be better in fact I am not sure what to expect. That is why I am using the Bic lighter of guns to learn on.
 
The floating Savage bolthead reduces the need for lapping in the lugs. Because it floats, lapping could make things worse - you don't know if you are lapping the lugs the way they would be positionned when the rifle actually fires. Facing the receiver is easy enough. You need a mandrel that fits the receiver, to quarantee that you are facing the receiver perpendicular to the barrel threads and boltway. You can easily tighten up the headspace.
Mysticplayer is a Savage guy. You should get his advice.
 
Accurizing accomplishes a couple of key things... First of all, it makes the bolt face absolutely perpendicular to axis of the cartridge, which helps keep the bullet aligned with the bore.

It also ensures that the bolt lugs are sitting on the integral lugs evenly (see above). Most Remington actions come "crooked" from the factory and benefit from accurization, however, most factory barrels/chambers are built to mediocre tolerances, making it unlikely that that you will reap the benefits without re-barreling. If a re-barrel with a match grade pipe is in your future, an accurization is probably a good investment.
 
tiriaq, On the lugs, I would not lap but single point the locking lugs true to bolt way along with the action face, if I did any thing at all. Like you say the front of the bolt floats and the bolt head pivots as well so it makes good contact. The face of the bolt would suffer from misalignment if the lugs were uneven more than anything.

As it is right now the lugs look like they are making good contact, I should put some smoke on them just to check.




Looch, I don't think I would need to re-bed the outside of the action would remain un changed.



Obt, this is all a long journey towards a new bbl.
 
Last edited:
Republic of Alberta said:
On the lugs, I would not lap but single point the locking lugs true to bolt way along with the action face, if I did any thing at all. Like you say the front of the bolt floats and the bolt head pivots as well so it makes good contact. The face of the bolt would suffer from misalignment if the lugs were uneven more than anything.

As it is right now the lugs look like they are making good contact, I should put some smoke on them just to check.




Looch I don't think I would need to re-bed the outside of the action would remain un changed.
Click to expand...

Most folks have a dye for that, blue I think, but as mentioned above, little if any difference you will notice, cause the barrel is still stock.
I bed guns , work or replace triggers, but any accurizing is done only when a good barrel is in order...and cost less cause the gun is apart anyway:cool:
 
As chance would have it, I had a factory XR100 blue printed. This is what happened, whether it proves little or nothing is up to you to decide.There's also a redone rifle with a match barrel story, for what its worth.

I bought a new XR100 in 22/250 and a 1-8 Lilja barrel with the idea of marrying them into a .22/243 Middlested. I shot about a box of whitebox and a few handloads through it in original form just to see if everything worked while it would still be covered by warranty. It shot around an inch for 5 in this admittedly short test. Nothing fell off, so off to the gunsmith it went. In 2 days time he had blueprinted the action, threaded and chambered the Lilja, pulled it off and then cut the threads off the original barrel then chambered it with the same reamer and put it back on. I wanted a fireforming barrel to save the W&T on the match barrel. When he passed it to me he jokingly asked what I was going to do if it shot well that way. Well, the original barrel shot the fireforming loads into 1/2", and would stick Berger 52 Match bullets into the same hole with fireformed cases. To this day I don't know what the Lilja does, it's never been fired.

Some time ago I had a M70 rebarreled to 22/250 without benefit of blueprinting. It was one of those cases where I thought it would be done, and he thought I didn't want to. Anyway, the rifle was no great shakes as a shooter with the Gaillard barrel, and I ended up getting Gaillard himself to pull it apart, square it all up and reinstall the barrel with a new chamber.(He didn't do the first job) There was a day and night difference in before and after. Turns out rifles like both lugs touching.

I wouldn't install a new barrel without squareing the action again. Neither would I ordinarily spend the money on squareing an action with the same barrel. If I had a lathe and reamer and knew how to run it, I might.
 
The Savage action we know had for many years reciever threads and lugs that were milled in one set up. As a result the threads and lugs were straight to each other. The face on the other hand was not touched in this process. Before this process actually took place, the actions were placed in a V block and hand slid into a grinding wheel to remove burrs and the face was normally out approx .003" to the threads & lugs. With the floating bolt head, there was no need to true the action.

A new shooter to our Saturday morning shoots had trouble with his brand new Savage 12BVSS. Long story short I checked it out and found something very impressive. Savage has changed their process to include the action face when they machine the threads and lugs and as a result, all are perfectly square to each other. AFAIK, these new style actions will have numbers under the rear tang, otherwise one can tell by the pattern of the action face machining.

If you decide to use a mandrel and jig, be sure not to tighten the set scews too much as it can distort the reciever threads. Wise advise from a BC smith. On a traditional Savage action, all you need to use is a freshly threaded stub and faced so it contacts the lugs when you screw on the action. If you think about it, the action threads would then be running straight on that perfect stub and the face and lugs are in full contact making this action dialed in as close to perfect as you can get. A simple face cut is all that is needed to "true" this action.

Toss the bent lug in the trash.

I wouldn't put a reamer in a factory barrel unless I was feeling real cheap and even then only if the original chamber was completely cut off.

Cheers,
Rob
 
PEI ROB said:
On a traditional Savage action, all you need to use is a freshly threaded stub and faced so it contacts the lugs when you screw on the action.
Cheers,
Rob
Click to expand...


This is good to know, I was not sure how to indicate the action in. I was going to insert a tight fitting and true rod into the bolt way at the back of the action an go off that but what you suggest is much better.

I will be making a jig to hold the action out of pipe with 4 screws up front and 4 at the back to adjust the action true. So far I have made up some copper tipped bolts and found a chunk of pipe that should work. I will be sure to be gentle when turning the bolts as not to distort the action.


As far as truing the nut. I was going to make a threaded rod and screw it part way in the nut. I would then take a jam nut and run it in the other side up against the rod. This would push the rod's threads true against the side of the nut threads that actually hold the bbl. The rod would be pre drilled on the end to accept a dead center. I would then use the center to align the nut in the chuck jaws parallel to the bed ways and then indicate the jaws in. That would give me the side of the threads that matter square to the lathe and let me face the nut.......Or just build a new nut I guess.




I won't be reaming the bbl, I will wait untill I decide what I want for a cartrige (260?) when it comes time to buy a good bbl for this thing.
 
Last edited:
My understanding of the issues affecting all solid front locking actions is PRESSURE and VIBRATION.

Seems that the main goal of lapping the lugs is to ensure both lugs make solid contact with the receiver so that under the pressure of firing, the bolt head doesn't bend or move. Doing so will allow the case to expand too much making extraction difficult and lead to off square cases.

Squaring the action up while lapping the lugs ensures that you have it all nice and straight which will help keep the case properly aligned with the bore during the firing process.

However, with so little of the case sticking out of the chamber, the alignment with the bolt face isn't going to 'move' the cartridge much, if any. Certainly, not until it makes a lot of noise.

Another critical issue to solve is the falling of the bolt when the sear is released. BR shooters showed that this can induce varying vibrations through the action and can change the ignition of the cartridge. Maybe so...???

But it definitely will affect how the lugs engage the receiver and how that controls the case during firing.

So if you don't bush the bolt body to the action, do you align the bolt lugs and receiver when the sear/bolt is cocked or down?

I feel that without bushing or fitting the bolt to the action, there is little point in doing much else.

With the Savage/Stevens, the floating bolt head eliminates all of these issues. At least down to accuracy levels that can be described as shooting in the 2's. Got one rifle that shot in the 1's with some zero's but that is another story.

First off the actions are very well machined from the factory. This from analysis of various gunsmiths posting their findings on various accuracy sites. However, being mass produced products, there is room for error.

The floating bolt head allows enough wiggle that both lugs MUST contact the receiver. There is simply no way for one lug to be suspended off the receiver face. Don't believe me, check any used Savage or stevens and you will find that both lugs make a sizeable amount of contact (you can see the wear on the back of the lugs). The more the bolt is used, the more the lugs make contact with the receiver through wear.

So immediately, there is near zero bolt head movement during firing. Now the bolt face may not be perfectly aligned with the chamber but then the solution to this problem is again so simple.

The barrel nut.

Anyone who has swapped barrels on these actions knows that there is just a hint of play in the threads. I expect this to be common in all factory rifles.

When these barrels are headspaced, they are indexed off the bolt face using a headspace guage. The slight 'slop' in the threads allow the barrel to stay true to the hunk of steel in the chamber that is also hard against the bolt head face. Voila, bolt face, chamber (assuming cut properly) and bore are in alignment when the barrel nut is tightened.

The slop in the barrel nut means it doesn't have to force the barrel to move and it can align itself with the receiver front.

So grossly exaggerated, the action face/lugs vs bolt face/chamber vs nut/receiver face could be in a zig zag fashion but still stay 'true' to its counter part.

And that is all I find matters when the firing pin hits the primer. I have built over a dozen rifles using both shoulder and nut headspacing. ALL rifles have shot to the potential of the barrel. Meaning barrels with 1/4 min accuracy potential have shot 1/4 min groups in a Savage/Stevens.

NONE had any work done to the actions except bolt timing to ease bolt lift (this they desparately need).

The next thing this wonderful floating bolt head does is isolate everything behind the action lug face from the front. Kind of a like a suspension. If you dry fire a savage and look at the rear of the bolt, it will drop and bounce around in quite an alarming way. But since it is not connected to the bolt head, doesn't affect it nor the cartridge being fired.

The fly in this wonderful set up is the firing pin hole in the bolt head. By design, it must be pretty big so that the bolt head can move around yet allow the firing pin to travel through.

There is simply no way to stop primer cratering with the action left in its orig form.

Now this is a GOOD thing because, it becomes a wonderful indicator of pressure. Even the thicker CCI primers WILL crater when pressures get into and past magnum levels.

You will get these very clear pressures signs which keep you in the safe/sane region of handloading.

A fully bushed firing pin hole in a fully supported, aligned and trued Rem 700 or BR action should not show this cratering even when pressures have exceeded sane levels. These wonders of the machinists art can easily mask pressures signs on loads that are into and beyond proof pressure levels.

Not my cup of tea as I quite like my body parts and see little point in distributing them around a firing line so that I can make a teeny tiny case act like a case twice in size.

So for those looking to build a rifle with 1/4 to 1/3 min accuracy potential and don't feel like spending alot of money, time or effort, you might try swapping a quality match barrel into an off the rack Savage or stevens and having some fun.

YMMV

Jerry
 
You can't true the nut if you lock it with another, it will get pushed to the hi side. A tapered stub or expanding mandrel is the way to true a nut.

Think rigid when making a jig.
 
I don't think I know more than anyone else when it comes to action truing, the necessity thereof, and methodology, but I know a bit.
Any alignment advantage of the Savage action likely comes as much from the fact that the sear does not influence the attitude of the bolt as it does from the "floating" bolt head. Most don't float enough to accomplish anything in the way of alignment.
Vee threads self center. A loose vee thread will still center up. it is impossible for it to tighten up eccentric to the axis of the thread. With a poorly machined (non-perpendicular) shoulder or a crooked nut, it is possible to have the thread tighten up in a misaligned state but not eccentric. The axis of the male thread will end up at an angle to the female thread axis sufficient to equalize the force between the crooked shoulder and the loose thread. With a true shoulder, the loose thread will center up; easily overriding the influence of a headspace gauge. If the thread is eccentric, it will tighten up eccentric. If it is co-axial, it will tighten up co-axial.
A quarter century of truing actions has mostly taught me it doesn't make the difference I was hoping it would! Nonetheless, I continue to do it because I don't want to be bothered by the potential effect of the unturned stone!
I have had some spectacular successes with some Remingtons which started out shooting quite poorly but lesser success with those which were shooting reasonably well. This makes sense when you think about it. On those which were greatly improved, it may well have been the improvement of the chamber alignment with the bore of the barrel (they were set back sufficiently to allow me to straighten flawed chambers) rather than the improvement of action concentricity etc.
One item which can have a real detrimental effect is a bolt face which is not perpendicular. I seen cases where correction of a badly off-square bolt face was good for a 50% improvement with no other changes made. The non-contacting lug is another which might account for some real accuracy problems and improving lug contact is bound to help. Keep in mind, this is in a case of non-contact. Fifty percent contact seems to work just as well as one hundred. It just doesn't look as good. Often, guys are trying to improve contact when there is really nothing wrong. The wear evidence which suggewsts misalignment is actually a result of the misalignment caused by deflection by the sear and cocking piece. Since actions are often cycled more empty than loaded, the wear pattern gives a false reading. Upon firing, the sear induced deflection is gone.
If you do a good job of truing your action, you will feel good about it anyway and you will, perhaps, have greater confidence in the outfit. These are good things! Regards, Bill.
 
I have to agree with Bill.

Truing the action will not make much difference to a good action, but it will make a poor action shoot alot better.

Bang for the buck, a good quality barrel will make an average action shoot like it never could with a factory barrel, and in most cases the action needs no trueing.

I still true my rem 700 actions though, with the right tools it's easy to do. The way I see it, if it did have an allignment problem, for the hour and a half it takes to true the action it's taken care of.

For the savage/stevens actions I would just do what Jerry says. He has excellent luck with them, and does very little work to the actions.

Dave
 
Knowing your action is true, square, concentric, and all the other things gunsmiths talk about (that I don't completely understand) means one less thing to think about when a rifle wont shoot as it should.

Could be the load, might be the scope, maybe a bad barrel??...But it isn't the bloody action!:D

The fix it first, fix it right, and make it perfect approach, tends to cure a bunch of gremlins IMHO.
 
You must log in or register to reply here.
Back
Top Bottom