Another Technical One for all you budding Gun Smiths

[nemasis243]

Right lads I have had a Pacnor barrel on a donar action and this shoots like a dream

Taking into account that the Round (Cases and Projectile) are virtualy all inside the tube , What are the benifits of having a custom action?

I have read on having thigs lapped ,but in the case of the everyday shooter who wants to shoot consistant good groups at Vermin ,would we see the benifits of spending £1000 on a nice shiny action?

[auquhollie]

It might be a better idea to have your action you have now printed. in other words taken back to what the blue print of that action should be.

 

What action have you got ?. Would only cost a few hundread to have the action printed and bedded into the stock. This would drive the group size right down.

 

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[6mmBR]

I think what Nemasis is trying to say is he's had a custom barrel fitted to a standard action. This rifle now does shoot one hole groups so I think he is trying to say is how can that be improved on?

Cheers

Dave

[Elwood]

If it isn't broke don't fix it. How can you improve a vermin rifle that shoots one hole groups? you can't!

I think the question should be why would you want to change it?

 

I think I would feel smug that I have found the holy grail without spending a big wad

[Guest varmartin]

Right lads I have had a Pacnor barrel on a donar action and this shoots like a dream

Taking into account that the Round (Cases and Projectile) are virtualy all inside the tube , What are the benifits of having a custom action?

I have read on having thigs lapped ,but in the case of the everyday shooter who wants to shoot consistant good groups at Vermin ,would we see the benifits of spending £1000 on a nice shiny action?

 

 

If your action and barrel assembly and loaded rounds shoot consistant tight groups...then you have a good one

 

It does not need `truing` or ` blue printing`...if it helps and someone asks...just say `YEP` sheees blue printed !!!

[shootingbags]

Steve Bowers once told me that once he has trued a Remington action , it has better ( closer ) tolerances than a custom action.

I think the only thing you would find then is resale value - you will get more for a second hand rifle built on a custom action than you will for a second hand rifle built on a trued action irrespective of the fact that they may shoot the same.

[casts_by_fly]

One of the bits of advice that is consistent across most of the varmint and switch barrel boards is:

 

Don't shoot the donor!

 

You plan and plan and plan to have this beautiful setup that you've designed for yourself. You pick out the barrel, action, stock and trigger. everything looks great and is ordered. The donor comes in before everything else and 'why not' go put a few down the tube. Next thing you know the donor is a great shooter that you just can't stand to tear apart. Now what? You've got parts coming in for a build that you now don't want to prodceed with. Now you have to either buy another donor or tear apart what might be a better shooter than you end up with later! Decisions, decisions!

 

I'd keep it as is. 'Truing' an action just means squaring up the lugs to the action and a few other things. There is always some range of alignment. Sounds like you've got a good one.

 

Thanks

Rick

[Vermincinerator]

Like Panther said, "need" NO, "fun" YES.

When you start engaging targets at a descent range you want to make sure that your equipment is capable of placing that shot if you do your bit.

For this you need a rifle that is capable of at least 1/2 moa groups "CONSISTANTLY".

If you have a rifle that shoots about 1 moa that means when you fire i shot at a one inch target sticker you clip the sticker at 9 oclock, put your rifle away and then shoot it another and it clips your sticker at 3 oclock thats one inch between the shots or at 500yds 5" and a miss on a small varmint.

You need you rifle to put that first shot in the same place each time you get out.

A custom barrel on a donor action will usually do this most of the time but a trued and accurized action will increase the number of times the rifle will hold 1/2 moa for the first shot and that it is what is important for a LR varmint rifle.

I have a rifle built on a Stiller Predator action, not as precise as a BR action but good for a varminter, i bought this action because i did not have a donor rifle and the cost was about the same as buying a donor and then accurizing it.

It does not shoot any better then the 243AI i used to have which had a PacNor supermatch barrel on a accurized Remmy action.

There are many shooters who completely dismiss a donor action and a custom action is the only worthy of having a rifle built on.

If these shooters can afford such a rifle then thats okay but what they must not do is look down on the guy who can only afford a accurized donor action.

 

Ian.

[Ronin]

Nemasis

 

 

before I could afford custom actions for rifles I bought second hand Rem 700's and had them blueprinted by a well known smith and chambered with the barrel of choice placing the barrelled action in the stock myself.

 

Two of my Rems built this way have won several competitions including hitting the Fly at Diggle (500 yds blue bottle sized target) twice (both years shot circa 2" / thats sub half MOA)

 

Now I am in a fortunate position to build rifles myself on custom actions (for myself) and I find that the rifles also shoot sub half - sub 1/4 MOA at similar ranges and beyond.

 

Which are nicer to shoot? - neither, they all have their qualities.

 

Custom over Blueprinted - well although the custom actions retained value is higher, so is the purchase price, it really is relative.

 

Certain gunsmiths charge over £900 for a supplied bluprinted Rem 700, well you can easily get a custom action for this money.

 

Aside from this is what other have said - if your donor action and PAc Nor are shooting now, then enjoy it.

 

Or get your smith to true the action, if its a Rem, all it entails for a "basic" job is squaring the lug abuttments and action face, bolt nose and rear lugs.

 

Sounds complex but it really does take longer to set up the action and bolt in the jigs than it does to actually cut them square.

 

Bear in mind that the barrel will have to be set back and chamber re-cut / reproofed so it gets spendy.

 

 

 

 

Enjoy what you have, when the barrel is wasted, then consider changing - just my 2p

[Vermincinerator]

Andy,

IMO the most important part of the blueprint, regarding rifle accuracy, would be to have the reciever threads re-cut concentric to the bore.

Apart from having the reciever face squared (a must anyway) if i could have only mod it would be that.

 

Ian

[Ronin]

Andy,

IMO the most important part of the blueprint, regarding rifle accuracy, would be to have the reciever threads re-cut concentric to the bore.

Apart from having the reciever face squared (a must anyway) if i could have only mod it would be that.

 

Ian

 

 

Ian

 

quite right, forgive my obvious ommission

 

 

I do mine with a special tool prior to mounting the action in the jig, possibly why I got "ahead" of myself there!!

[Vermincinerator]

Andy,

What you said is corect though, a basic blue-print does not usually include the re-cutting of the reciever threads because it is the most labour intensive and thus costly portion of the process.

Without this part of the process i think the rest of the blue-print is a complete waste of time

 

Ian.

[col48]

Andy,

What you said is corect though, a basic blue-print does not usually include the re-cutting of the reciever threads because it is the most labour intensive and thus costly portion of the process.

Without this part of the process i think the rest of the blue-print is a complete waste of time

 

Ian.

 

 

hi Ian

 

as i understand it, a blueprinted action consist of

action abutments re cut

action face re cut

action threads re cut

bolt lugs re cut

bolt face re cut

 

Any thing less and you don't have a blueprinted action.

i don't believe you need the bolt sleeving.

 

just how i see it.

 

ATB

Colin

[Vermincinerator]

You are right col anything else is not a proper blue-print but i am afraid this type of so called "blue-print" is all too common

Look at Darrel Hollends video, he just runs a tap down the thread which in my opinion is a waste off time because it does nothing to improve any accuracy and makes any other work carried out on the action worthless.

Squaring the face of the reciever and screwing on a custom barrel would IMO prove equally as accurate as a partial blue-print and a lot cheaper.

 

Ian.

[col48]

You are right col anything else is not a proper blue-print but i am afraid this type of so called "blue-print" is all too common

Look at Darrel Hollends video, he just runs a tap down the thread which in my opinion is a waste off time because it does nothing to improve any accuracy and makes any other work carried out on the action worthless.

Squaring the face of the reciever and screwing on a custom barrel would IMO prove equally as accurate as a partial blue-print and a lot cheaper.

 

Ian.

 

hi

 

i just don't see the point in going to all the trouble in setting the job up, and this part takes all the time up(as i think ronin has all ready said) and then only doing 1/2 a job.

 

a bit like setting your barrel up for screw cutting and then not putting a new crown on wile its set up.

 

ATB

Colin

[Vermincinerator]

hi

 

 

 

a bit like setting your barrel up for screw cutting and then not putting a new crown on wile its set up.

 

ATB

Colin

 

That happens as well mate.

 

Ian.

[Ronin]

Fortunately the tooling I own allows you to center the tap so it runs concentric to the centerline of the action before engaging the threads.

 

Once the threads are cut, the action (including tap) is mounted in a jig and set in the lathe then the action can be clocked at two points on the tap body, this makes for a very precise set up before cutting lugs and action face.

 

All this to remove .002" to .004" on average!!!

[col48]

Fortunately the tooling I own allows you to center the tap so it runs concentric to the centerline of the action before engaging the threads.

 

Once the threads are cut, the action (including tap) is mounted in a jig and set in the lathe then the action can be clocked at two points on the tap body, this makes for a very precise set up before cutting lugs and action face.

 

All this to remove .002" to .004" on average!!!

 

hi

the way i look at it is like this.

 

if you have .002 to .004 on the action abutments, and then .002 to .004 on the bolt lugs, all so your action face is .002 to .004 out of squire, then your bolt face is the same and finally your action threads are not concentric, well you can see y your rifle is not shooting as she should,and they all add up.

now I'm not an expert on this but i would have thought that if you don't put your action threads right you will be putting stress on the barrel/action witch we all know is not the desired effect we are looking for,thats not to mention the action to bore and boldface concentricity.

 

ATB

Colin

[Ronin]

Col

 

yes its almost like that, but not quite.

 

If the threads are not concentric, this causes the barrel tenon threads to be obviously out of alignment with the bore / action centerline.

 

So by cutting the action threads concentric and its just really a shaving not a cut in the true sense of the word, your threads should be true - this is pointless however, if the barrel has not been set up correctly before cutting the tenon and barrel thread (another issue entirely)

 

Now, if one takes a cut off the action face to square it, you find (usually) that .002 - .004 is all that is required to get a clean 360 degree cut - that is all that this needs.

 

This reduction in action length affects the barrel tenon length only nothing else and this minute length should not have any effect on the strength of the barrel / action join or integrity of the action.

 

By removing a small amount from the lug abuttments and rear bolt lugs (again around.002") from each is all that I have found on the actions Ive done this affects the clearance on the bolt handle / action cut out - which is about .30" anyway - so minus .004" has no detrimental affect.

 

The bolt face - again just a fine clean up cut removing .002" is all thats required, this material removal (like all the rest in the truing process) affects chamber and headspace - so if your using the same barrel, this needs setting back and recutting or re-headspacing at best.

 

 

All these steps affect one another and if one isnt done, there really is little point in doing any.

 

Having read a bit about such things, I believe that the biggest factor in rifle accuracy is removing the movement at the time f ignition in the barrel / action interface (in other words the action face and barrel tenon face MUST be absolutely square. Another major factor is that the lugs must be square and have equal bearing and the bolt face has to be square.

 

If any of these componants are out of true the pressures exerted on them upon finring meand they WILL move and that has a detrimental affect on repeatable accuracy.

 

Skimp on one and you skimp on them all

[Vermincinerator]

Andy,

Running a piloted tap down the threads and then hoping its concentric is not the right way to do things.

I am aware of tooling from dave Manson which allows you to re-cut the threads, is this what you are using?

It sounds like you are not because the Manson tool firstly reams the basic internal diameter 010" oersizeand then the tap cuts the basic effective diameter + .010".

This is not a slight shave.

The same principle is used when single point re-cutting the reciever threads in the lathe, skim the bore concentric to the bolt raceway removeing whatever amount it needs to cleand up and then deepening the threads by the corresponding amount.

Once this operation has been carried out a factory barrel will no longer fit as the tenon thread will be to small, so a custom barrel must be used with the tenon thread cut plus the amount the threads were deepened on the reciever.

 

Ian.

[Ronin]

Ian

 

 

Agreed, I see no value in running a tap into the action as per Darrel Holland's video, I cannot see how the tap will run or cut concentric threads - surely it will follow the path of least resistance?

 

However the Manson tool in question is available in standard and +.010" oversize thread and as you know it runs in bushings that fit tightly withing the action raceways.

 

 

I use the standard sized tool, which takes a very light cut of any threads that are not concentric to the bore centreline.

 

Of the actions I have looked at so far, all have taken light cuts only.

 

I know there is discussion over which method is best (Manson Tool or Single Point threading tool) and the jury is still out over which if either is more accurate or leads to more concentric threads.

 

The discussion on some forums has involved the Likes of Dave Tooley, Butch Lambert, Dennis Sorrenson etc all smiths of high regard in the US, no one seems to be able to say one method is better over the other.

 

For what its worth, when the action is dialed in to the jig, I have managed to get runout down to .0003" (three tenths of a thou) at each end of the action

, this is the same as my lathe spindle runout using a test bar - dont think I can better that.

 

 

 

This method works for me.

[Vermincinerator]

Andy,

Cutting the threads using the tool with the standard size tap will not correct threads that are out of concentricity, all it will do is remove any high spots in the troughs and effectively give you an out of round thread slightly oversize in places, not good in my opinion.

To ensure the threads are concentric to the boreline a full 360 degree cut must be taken, whether its five, ten, or twenty thou to clean up the bore and then the corresponding amount extra added to deepen the thread.

The point of whether single point cutting or piloted tapping of the receiver threads is better, can only apply if an oversize tap is used and as both methods produce the same results they are both equally as good but using a standard size tap even if piloted is not actually achieving anything.

 

Ian.

[Ronin]

I wonder why PTG, Manson and the others that make similar products sell them in standard size then and iv'e never heard of anyone criticising the standard "thread clean up over the +.010" oversize version"

 

Which when you think about it is "only" (I know its alot when its under 65,000psi) removing +.005" overall diameter of the threads anyway.

 

Given that the 16 TPi pitch is (guessing here) .075" - .080" deep, any ovalness in the standard thread after using the standard tooling will be absorbed in the new barrel thread - which is cut to be a close fit.

 

 

I'm pretty sure the likes of Dave Manson would not allow a tool to be released if it was considered to be questionable in terms of safe use?

 

Do you think that the standard tool shouldnt be used Ian - should I send it back if its unsafe - bit concerned over what youv'e written - should I use it or not?.

 

 

A few moments of thought later, I think I will get the oversize tap and re do the actions I have already started on, I would rather be 100% sure than in position of doubt over this matter. (they are peanuts to buy anyway)

[Vermincinerator]

Andy,

I think we could agree that they make the tooling with the assumption that all actions are concentric anyway, there is also the rare possibility of an undersize thread

I too have not heard anyone criticise the standard thread clean up method but thats all it is a "clean up" probably better then nothing, i suppose you could liken it to a partial clean up of a case neck, helps achieve consistant neck tension but not as well as a full neck turn.

For maximum accuracy potential and concentricity the threads must be cut oversize

Dont forget a receiver thread that is .004" off centre will take a minimum of .008" to clean it up.

I think you are right to go for the oversize tooling its the only way to go unless of course you take the plunge and have a try at single point cutting the thread, its not that difficult, engage the half nuts, pick up the thread using the compound slide and rotate the chuck by hand untill the tool runs into the lug recess.

 

Ian.

[Ronin]

 

Whilst happy to work to close tolerances on external threading, I am not sure my skill level is such that I want to try and single point cut a blind bore running the risk of crashing the lug abutments.

 

I'll go with a ten thou oversize tool from PTG for now, as even the experts admit there is little or nothing to be gained in one method over the other.

 

(and its so simple a ham fisted buffoon like me can do it )