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Blueprinting and accuracy improvement - any proof?

I ordered PTG full truing system and a set of 10 incremental headspace gauges.

As for what standard would satisfy me - I would be happy with a 25 or more round mean radius or radial standard deviation before/after best-effort 100 yard benchrested group (under similar conditions and with the same ammo).
 
I have friends who have Remington actions whose threads were far enough out that none of the systems like the one that you have ordered would have fixed them. (The thread diameters that they had to be single pointed to are larger than any of the taps that I have read about.)Beyond that, you will need to ream the bolt raceway and fit a larger diameter bolt , or have the bolt sleeved to get to where you need to go. Also, I am ignorant as to what a set of 10 incremental headspace gauges would be, exactly, or what they would be used for. Could you explain?
 
It is a gauge set from min to SAMMI max in 0.001 steps. It will allow me to see where in the headspace range I am rather than just tell me if I am within the legal range. I want it to track movement due to lapping lugs, machining the receiver face, or making other changes. For a bolt gun I like minimal headspace. For a semi or full auto, I like min+0.003. SAMMI allows 0.003 of overlap anyway between max cartridge and min chamber - so min+0.003 is really like what traditional engineering practice would call min.

http://www.midwayusa.com/viewproduct/?productnumber=561125&utm_source=froogle&utm_medium=free&utm_campaign=649
 
Good idea. If you take much off of the lugs and seats, you may have to move the bolt handle to reclaim full extraction cam function. If you are primarily shooting factory ammo (in a bolt action) I believe that having minimum headspace may be beneficial to accuracy, but if you intend to shoot reloads, allowing a little more room may help guarantee that your FL die can be set to properly bump the shoulder of a fired case, and the difference from minimum will only exist for the first firing, assuming careful die setup. Also, since I typically get the best accuracy with bullets seated longer than touch, this tends to reduce any detrimental effect to accuracy that a slightly longer headspace might otherwise have, on that first firing.
 
There is really no way to do an apples to apples comparison because NO two actions, let alone three will ever be the same. Some will benefit more than others.
The thing to keep in mind is that Remington only pays approx. $25 for a reciever, that includes all the drilling, tapping, rollmarking, heattreating etc. I know the front of the actions aren't square because the machining marks show they were deburred on a belt grinder.
The other side of the equation is the mental side. A shooter will shoot better when he knows he has prepared himself and his equipment. There will not be any voices in the back of his head if he knows all bases are covered, HUMAN NATURE!
 
One more thing that could be done to test the difference between factory actions and a straight version of the same action would be to buy a high quality Remington clone, and bed it to the highest standard in a factory stock, and then switch a factory and/or custom barrel back and forth between it and an action that is known to have measurable issues with lug contact, squareness, thread concentricity, and alignment, and bolt clearance (that was properly bedded into an identical stock). If both used the same trigger and scope (properly mounted on both) what you would be seeing would be the difference that the actions made. One might have to use a few shims to hit headspace, and an aftermarket lug might have to be ground to factory thickness, but I think that it could be done, and it would give you a relatively economical and non destructive way to look at the difference. Personally, I feel that a match chambered custom barrel, of the highest quality, would be the best to use for such a test. Doing that would also address the issue of how much of the accuracy improvement from stock is the barrel, and how much is the action.
 
If the edges were deburred that would not affect the perpendicularity of the face.

I agree that no one action would prove much. It would take about 30 actions to really show anything. 10 would start to show something.
 
If and when you see that many Remington bolt action receivers you will come to realize the receiver face's are not turned as you keep stating....
No clue where you came up with that one.....
Set up all 30 of those 700 actions and you will see the receiver rings are never true to the bolt bore raceway..
 
One of the reasons that factory actions are all lacking in straightness, to one degree or another, is that they are machined before they are heat treated. Because of their asymmetrical cross sections, the rate of cooling is not consistent.Thinner parts cool faster than thicker.

Speaking to the need to have larger samples. The anecdotal examples that I have written of, and others, point out what can happen, not what will happen every time, BUT when specifying a project I like to eliminate every source of failure that I can possibly address. Knowing that there have been convincing instances where rifle builds that were based on factory actions failed to reach their design goals for accuracy due to shortcuts that were taken in the area of action work leaves me with but two choices, have everything done, or start with an action that does not require fixing. I have seen too many expensive projects that failed to meet their owners expectations due to shortcuts being taken to want to fall into the same trap myself. Many times I have been asked about how to have a rifle built. If the questioner will do what I tell him to, they work. If he indicates that he does not want to be bothered with doing everything correctly, I wish him luck, and avoid further discussion of that project. Its sort of like the guys who want to shoot better, but when it comes down to specifics, don't want to change anything that they are doing...same breed of cat.
 
The front ring is not just deburred, the whole surface was done. But i dont think it was done on a disc sander. It looks more like fly-cutter marks to me. My theory is: "X" amount of blanks are stood up in "loading trays" in a vertical mill, first all raceways are drilled to .70X, then all are counterbored to .9XX for tapping (which also makes locking lug abuttment), then they are all tapped 1.062x16, then they are all fly cut "square". Then they are taken to a big hydraulic press where the locking lug slots are cut with a broach cutter.

I really dont think they ever see a lathe!!!!

But i may be wrong.....I was only 1 time before so it is possible!!!! ::)
 
Just what kind of machine did you see on the tour that they were held in ??????
With all the tool marks I've seen over the years on em it's not a lathe............
 
Precise action work is set up using the CL of the bolt raceway as a reference. Given the experience of gunsmiths doing this work, using the lug seats may not be giving the best possible results. Another problem is that one needs to set up an action in a lathe to evaluate its trueness. Anything less is just guessing.
 
And a mandrel that is a tight fit for a particular action would be made on a ? And the mandrel would be supported in...? And, using it to evaluate the position, dimensional correctness, and alignment of the action threads relative to the raceway CL would be done how?
 
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