Gunsmithing Making an action truing jig.

[GasLight]

Well, my next project is going to be building an action truing jig. I have some schedule 80 pipe, I built my rear spider out of this stuff, and it is nice to work with, and would be suitable for a truing jig. That said, I think an aluminum one might work just as well, and be lighter to work with. I was thinking I would just use a steady rest to mitigate some of the weight of the jig if I use the schedule 80.

Anyway, now to my question. Anyone give me dimensions of their aluminum truing jig? What length, interior and exterior diameters? What are your thoughts on using aluminum vs steel?

Thanks!

Dave

 

[bohem]

Re: Making an action truing jig.

Why are you worried about what it weighs?

I made mine from DOM Seamless tube 2" OD, 1/4" wall.

 

[Ferryman]

Re: Making an action truing jig.

I am making mine from 6061 4" O.D 2.5" I.D 0.75 Wall thickness.

8" OAL

Look at the one 300Sniper made, it is his one I am copying

 

[x ring accuracy]

Re: Making an action truing jig.

I used aluminum. Dimension wise, take a S.A. and a L.A. and compare the difference. You will make a series of holes for the front of the action and 2 sets at the back of your jig for SA and LA respectively. Not that hard. Won't give you the numbers as you need to do the math yourself. It is very basic. Sorry and flame suit on. And yes. 300's is a piece of artwork.

 

[GasLight]

Re: Making an action truing jig.

I appreciate the 'make him do it himself' approach. It is a good thing. I was most concerned about how thick the walls need to be more than the length. I am not sure I will make dual holes in the rear of the jig, as to me 1/4" won't make much difference, I will just make sure the placement of the bolts will allow me to protrude the action slightly more on a long action.

Mostly my question was to determine if I could find a piece of tube of some sort, or if I would need to make it out of a solid round.

Thanks!

Dave

 

[wnroscoe]

Re: Making an action truing jig.

Just make it so the set screws catch the front receiver ring, don’t even consider the rear receiver ring. Use your receiver dimensions to reverse engineer the fixture as shown.

 

[300sniper]

Re: Making an action truing jig.

if you look at speedymetals.com, you will see lots of different sizes of tube and materials. the one i am using now was made from 4" od, .75" wall 6061t6 aluminum tube about 7" long. the direct d1-4 mount truing jig i want to make will most likely use 4" od, .5" wall 1020 dom tube. in my mind, the weight isn't a bad thing.

 

[Glen Seekins]

Re: Making an action truing jig.

Mine is 4" OD 1.55 ID, full action length.

Be careful how large you make the ID. The more screw length sticking out (inside) the less ridged it will be.

 

[Hooper]

Re: Making an action truing jig.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wnroscoe</div><div class="ubbcode-body">Just make it so the set screws catch the front receiver ring, don’t even consider the rear receiver ring. Use your receiver dimensions to reverse engineer the fixture as shown.

</div></div>

I have a spider just like that for threading short pistol barrels. Do you find it time consuming to dail actions in on the short version like that? It takes me twice the time vs. threading a barrel through the spindle.

 

[Bryan27]

Re: Making an action truing jig.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wnroscoe</div><div class="ubbcode-body">Just make it so the set screws catch the front receiver ring, don&#146;t even consider the rear receiver ring. Use your receiver dimensions to reverse engineer the fixture as shown.

</div></div>

I had to take a second look at your set up, at first I thought your picture just happened to show a rear spider to hold the outboard end for doing barrel work due to its length. Most of the action truing jigs I've see appear to be full action length, or at least close to it. The second pic clarified it for me, the rear ring sticks into the hole of the chuck and everything is supported by and adjusted at the front ring. I like that it keeps the work closer to the chuck rather than having 8 inches of truing jig and action hanging out past the chuck, unsupported. It looks pretty close clearance on the I.D. with the shim and action in it, approximately how much adjustment do you have? Seems like the less adjustment you have the more rigid it'd be, as long as there's just enough to dial it in. As usual, I'm impressed with your work and can tell that some thought went into it.

 

[JimT]

Re: Making an action truing jig.

I'm going to shamelessly copy (as best I can) 300sniper's latest idea of combining the back plate and the jig to eliminate the chuck. I will have to wait until I get home to find out what size DOM tube to use, as I will be using it for M700's and M70's. The Winnies will require more room due to the receiver design.

 

[300sniper]

Re: Making an action truing jig.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JimT</div><div class="ubbcode-body">I'm going to shamelessly copy (as best I can) 300sniper's latest idea of combining the back plate and the jig to eliminate the chuck. I will have to wait until I get home to find out what size DOM tube to use, as I will be using it for M700's and M70's. The Winnies will require more room due to the receiver design. </div></div>

lol, you'll probably get yours done before i get mine done. i'll still take credit for the idea though

 

[wnroscoe]

Re: Making an action truing jig.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hooper</div><div class="ubbcode-body"> Do you find it time consuming to dail actions in on the short version like that? </div></div>

Not at all, it's faster than you'd think.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bryan27</div><div class="ubbcode-body"> Most of the action truing jigs I've see appear to be full action length, or at least close to it. The second pic clarified it for me, the rear ring sticks into the hole of the chuck and everything is supported by and adjusted at the front ring. I like that it keeps the work closer to the chuck rather than having 8 inches of truing jig and action hanging out past the chuck, unsupported. It looks pretty close clearance on the I.D. with the shim and action in it, approximately how much adjustment do you have? Seems like the less adjustment you have the more rigid it'd be, as long as there's just enough to dial it in. As usual, I'm impressed with your work and can tell that some thought went into it. </div></div>

Full length truing fixtures made from aluminum will allow you to flex the receiver and make it hard to get the mandrel out...bad juju for great work. My fixture doesnt go into the spindle bore or chuck at all. It bottoms out on the chuck face and barely clears the jaws. I made it too tight at first and had to re-bore it slightly over sized. Works like a charm now and holds the receivers tight as new "P"

These pics will make it clearer

Dialing the fixture in first

 

[GasLight]

Re: Making an action truing jig.

Do you use the bushing in replace of brass tipped screws? Or is there another purpose for the bushing?

Thanks

 

[Glen Seekins]

Re: Making an action truing jig.

the way Rosco is doing it with the use of a collet around the receiver IS the way to go. then you dont have to worry about the screws digging into the receiver. The closer the hole is to the OD of your collet/receiver setup the closer you will start when dialing in the action.

Instead of using tubing, I would just get a chunk of round stock and use your lathe to bore the center hole.

http://www.mcmaster.com/#aluminum-round-stock/=6z2inl

 

[wnroscoe]

Re: Making an action truing jig.

The aluminum sleeve is used to keep from marring the receiver finish. It also helps to hold things "tight" No brass tipped screws either.

The fixture started out as a piece of round 2.5" steel stock. I turned it to just get a clean up pass and then drilled/bored to about 1.400"ish. The aluminum sleeve has an ID of 1.355" / 1.360" and an OD about .030" under the steel sleeve ID. No real secrets concerning the dimensions, just reverse engineer it based on the receiver OD

Another pic showing it all assembled

 

[Bryan27]

Re: Making an action truing jig.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wnroscoe</div><div class="ubbcode-body">
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bryan27</div><div class="ubbcode-body"> Most of the action truing jigs I've see appear to be full action length, or at least close to it. The second pic clarified it for me, the rear ring sticks into the hole of the chuck and everything is supported by and adjusted at the front ring. I like that it keeps the work closer to the chuck rather than having 8 inches of truing jig and action hanging out past the chuck, unsupported. It looks pretty close clearance on the I.D. with the shim and action in it, approximately how much adjustment do you have? Seems like the less adjustment you have the more rigid it'd be, as long as there's just enough to dial it in. As usual, I'm impressed with your work and can tell that some thought went into it. </div></div>

Full length truing fixtures made from aluminum will allow you to flex the receiver and make it hard to get the mandrel out...bad juju for great work. My fixture doesnt go into the spindle bore or chuck at all. It bottoms out on the chuck face and barely clears the jaws. I made it too tight at first and had to re-bore it slightly over sized. Works like a charm now and holds the receivers tight as new "P"

</div></div>

I didn't mean to imply that the fixture goes into the bore of the chuck or spindle, what I was getting at was that only the amount of action necessary is held in the jig and the rest of the action is behind the face of the chuck and out of the way. I like that the part of the action that is actually being worked on is closer to the chuck where it is going to be more supported rather than 8 inches from the chuck where physics is more likely to take it's toll on the work. Would that be correct?

 

[wnroscoe]

Re: Making an action truing jig.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Bryan27</div><div class="ubbcode-body">Would that be correct? </div></div>

Yep, you nailed it.

 

[wnroscoe]

Re: Making an action truing jig.

This is where I got the idea. This guy is a true craftsman, wish the original idea was mine.

http://www.bryantcustom.com/articles/true.htm

 

[x ring accuracy]

Re: Making an action truing jig.

I think your question may be answered this way. Schedule 40 or 60 pipe....40 works, 60 is better (thicker). I may be late on this reply, sorry.

 

[BlackOps Tech]

Re: Making an action truing jig.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wnroscoe</div><div class="ubbcode-body">This is where I got the idea. This guy is a true craftsman, wish the original idea was mine.

http://www.bryantcustom.com/articles/true.htm </div></div>

I made one of these about a year ago and quickly decided that it's definitely the way to go. After using it a few times, I made a few tweaks that made it much better. I re-designed the "collet" that holds the receiver and changed the type of screws I was using. It allowed for much smoother indicating and I can dial in a receiver in about six minutes....I sent the design to PT&G and Dave will be making them soon.

 

[GasLight]

Re: Making an action truing jig.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Skunkworks</div><div class="ubbcode-body">

I made one of these about a year ago and quickly decided that it's definitely the way to go. After using it a few times, I made a few tweaks that made it much better. I re-designed the "collet" that holds the receiver and changed the type of screws I was using. It allowed for much smoother indicating and I can dial in a receiver in about six minutes....I sent the design to PT&G and Dave will be making them soon.</div></div>

That is cool. I was already thinking about a diffent collet design myself, perhaps this will be the same idea as yours. Guess I will have to see.

Any hints as to what the new type of screw is that works better?

Also, it looks as though William uses a different collet design than shown on Bryant's page.

 

[Field]

Re: Making an action truing jig.

I have one from Pacific tool that I use for Winchesters but built one like Wnroscoe for Remingtons and like it much better.

 

[BlackOps Tech]

Re: Making an action truing jig.

Basically anything that won't grab or dig into the collet material. I think everyone that has made one has made it a little different. I use the Gre-Tan for Winchesters, but there is no better way to hold/blueprint a round receiver that is easily tweaked.

 

[300sniper]

Re: Making an action truing jig.

something i have thought about but not implemented yet was a ball and socket type pad at the end of each adjustment screw, kind of like the swivel end on a c-clamp. this idea was more for my spider chuck and rear spider for barrels but it could probably also be used for a truing jig. i was thinking about making the ball on one side and a vee on the side that sits against the barrel.

right now, i have been using a copper plumbing cap with two hardened flat washers inside at the end of each adjustment screw. i greased them all up to hold them in place. the flat washers and grease act like a bearing to keep the adjustment screws from digging into the copper cap and also keep the copper cap from trying to turn when adjusting.

 

[C Snyder]

Re: Making an action truing jig.

I made mine from a 4" OD pipe with 3/4" wall thickness. Permanently mounted to a D-cam and it works great. Plus it is universal I can do any action or barrel that will fit in the spider. I will be making some extra nut with brass protectors that swivel like what 300sniper was saying. Less chance to mar the action or barrel. Currently made the brass caps out of old 7mm win mag brass.
Here are the pics

 

[2Shots]

Re: Making an action truing jig.

I know this is an old thread, it was brought to my attention a week or so ago when discussing action truing jigs with a friend of mine. The Roscoe (or ever is taking credit) design is an awesome jig, has anybody made any changes in the design recently. I have steel stock in the lathe as we speak and have bored to the 1.40 range and am ready to finalize the steel ID and start on the aluminum collet. Is the wall thickness of the aluminum collet in the .100" range? And I assume the .030" clearance from collet to steel is enough to allow movement?

 

[jonaddis84]

Re: Making an action truing jig.

I just made one...

Outer Steel-
OD 2.5 cleaned up
ID 1.602

Alum sleeve
OD 1.571
ID 1.365

I used 5/16-24 set screws. Only thing I did to try to improve is put 1/4" chrome balls under the set screws to take away the friction and hopefully make for smoother adjustments. Not sure how much it helped, and they are a pain in the ass since you have to keep the sleeve inside to keep them from falling out.

I didnt even slit the aluminum, with a tight enough fit around the action I dont really see the need to slit it.

 

[2Shots]

Re: Making an action truing jig.

Sounds pretty close to what dimensions I was considering. .005 clearance per side on the collet to action and slightly over .030 total on the collet to steel. I'll think about the steel ball thing, may have to drill out the screws and stake them in. Thanks for the info.

 

[LRI]

Re: Making an action truing jig.

Thoughts:

A variety of multi jaw chucks can be bought for reasonable rates these days.

What if a different approach was considered? A basic rule in machining is to try and avoid extending a part more than 2.5x its diameter unsupported. It is what it is; a fact.

SO what if a guy were to make a baseplate that allows a chuck to articulate at the spindle nose slightly (so that the receiver bore can be aligned tangent to the spindle) while still providing for an independent jaw arrangement that would allow for the receiver bore to become concentric to the spindle axis?

One step further:

Next aquire a set of jaw blanks and contour (bore) them to the receiver od so that complete captivation is achieved for 360* instead of point contact by a handful of set screws.

In the case of a receiver like a winny it be simple enough to have the geometry cut with a wire edm.

The idea being uber solid work holding with maximum part captivation and nothing hanging out in space. It would require a large spindle bore ID though which could be problematic for some machines.

Just a thought.

Good luck on your project op!

C.

 

[2Shots]

Re: Making an action truing jig.

I think I'll stick with this collet concept first, I for sure don't have the machining skills to build your articulating device! Thanks for the help guys.

 

[SSC]

Re: Making an action truing jig.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wnroscoe</div><div class="ubbcode-body">

</div></div>

Mine is very similar to Roscoe's. I'm just not a fan of hanging a giant jig unsupported.

 

[E. Bryant]

Re: Making an action truing jig.

How about one more thought for consideration - is there a substantial increase in rifle performance that is gained by adjusting the the action's axis to that of the lathe axis? Or is it acceptable to simply clamp the action's OD in a 4-jaw (maybe even using custom "soft jaws" with the appropriate bore ID), indicate the bore raceway at only a single point, accept the slight angular deviation, and gain rigidity and ease of setup?

I ask because I haven't seen huge angular deviations between the bolt raceway and the action ID during my (very) limited experience in truing R700 actions - maybe a couple thou over an inch length of the indicating rod. That sounds like a lot to those that are indicating to within a ten-thou, but I have to imagine that much of that precision is lost to part deflection during the machining process.

Anyways, please don't take this as criticism of methods that have been advocated by those with considerably more experience, or as advocacy of sloppy set-up practices. Just looking for some discussion on the matter...

 

[SSC]

Re: Making an action truing jig.

If you are building rifles for yourself, sure I think you can get away with doing less. I know that my customers come to me instead of the other local guys because I take the time and effort to go the extra steps.

 

[jonaddis84]

Re: Making an action truing jig.

Chad,

I understand the need for rigidity in setup, but speaking of action truing where we are talking about removing a few thousandth max of material are you really gaining anything? I mean the threads are the only part you are removing any substantial material, and you're doing it in .002 max increments anyway.

I know always have the best setup you can, but this seems like splitting hairs for no reason. It's also not just supported by tiny set screws, rather a collet basically.

 

[STR]

Re: Making an action truing jig.

Rigidity and machining go hand in hand if you are to have accurate quality cuts. There are different levels of rigidity depending on the job at had. Cutting .002 or less per cut on any surface of a piece of work that is less than 1.5 inches in diameter doesn't require that it be clamped down like the out put shaft on a cruise ship. Eight bolts, and 8 inches away from the chuck will work more than fine. That has been proven for years. That said, I'm always open to new/proven ideas that work, so I tried Williams idea for my self. It is now the one I use all the time. It is small enough that I can use it on my Heavy 10 instead of the heavier Colchester 13x40. It is also easier for me to reach alignment faster than the long jig you all have seen in my video. That long heavy jig is not ideal for the smaller lathe. Thank you William for the idea.

 

[jonaddis84]

Re: Making an action truing jig.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: STR</div><div class="ubbcode-body">Rigidity and machining go hand in hand if you are to have accurate quality cuts. There are different levels of rigidity depending on the job at had. Cutting .002 or less per cut on any surface of a piece of work that is less than 1.5 inches in diameter doesn't require that it be clamped down like the out put shaft on a cruise ship. Eight bolts, and 8 inches away from the chuck will work more than fine. That has been proven for years. That said, I'm always open to new/proven ideas that work, so I tried Williams idea for my self. It is now the one I use all the time. It is small enough that I can use it on my Heavy 10 instead of the heavier Colchester 13x40. It is also easier for me to reach alignment faster than the long jig you all have seen in my video. That long heavy jig is not ideal for the smaller lathe. Thank you William for the idea. </div></div>

I agree, I made the switch after hanging out at SAC for a day, its much easier to use than the long ones.

 

[STR]

Re: Making an action truing jig.

I agree, I made the switch after hanging out at SAC for a day, its much easier to use than the long ones.


Wow, SAC for a day!! He would have had to call the cops to get me to leave.

 

[LRI]

Re: Making an action truing jig.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jonaddis84</div><div class="ubbcode-body">Chad,

I understand the need for rigidity in setup, but speaking of action truing where we are talking about removing a few thousandth max of material are you really gaining anything? I mean the threads are the only part you are removing any substantial material, and you're doing it in .002 max increments anyway.

I know always have the best setup you can, but this seems like splitting hairs for no reason. It's also not just supported by tiny set screws, rather a collet basically. </div></div>


There's a reason flagship companies use robust, rock solid equipment. It was made very evident to me when I used to work for them.

My fixture at close to 200lbs.

My surface finishes: I encourage you to decide for yourself if its worth it. For me it is and our clients sure seem to like it as well. Precision gunmaking is about splitting hairs. Just like racers laboring for hours to wring out another 10hp from an engine.

 

[Boogaloo]

Re: Making an action truing jig.

Ultra nice work there sir. Thank you for sharing!

 

[jonaddis84]

Re: Making an action truing jig.

In old pussy fixture hanging +10" from the spindle bearing, and on a lathe that probably weighs 1/20th of your mill...

I should also point out this was probably only the 3rd or 4th action Id ever trued at the time.

 

[boltstop101]

Re: Making an action truing jig.

Hi I have found nerdgun.blogspot.com very useful I have learned allot there . Hope you find this information useful as-well.


http://nerdgun.blogspot.com/2011/08/making-universal-blueprinting-jig.html

 

[csdilligaf]

Re: Making an action truing jig.

Chad, I think I might try trueing on my Haas mill. How hard is it to get it indicated true that way? Are you shimming the indexer or is it on some kind of tilting plate?
Also to catch the thread does your cadcam have a feature for that?

 

[jrm850]

Re: Making an action truing jig.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: csdilligaf</div><div class="ubbcode-body"> Chad, I think I might try trueing on my Haas mill. How hard is it to get it indicated true that way? Are you shimming the indexer or is it on some kind of tilting plate?
Also to catch the thread does your cadcam have a feature for that? </div></div>

I'm interested in how he indexes the threads also! I was thinking about turning an extended tennon to screw into the existing threads and indexing externally so I could get a good visual. Thinking about it is as far as i've gone.

 

[LRI]

Re: Making an action truing jig.

While I always encourage folks to push new ideas and I try to be helpful, I'm not in the business of running a school.

This trade is as competitive as any. Certain things need to stay in my house and this is one I'd rather not share.

Good luck.

C.

 

[csdilligaf]

Re: Making an action truing jig.

Understood, that makes sense, I forgot that you do it for a living.

 

[jonaddis84]

Made a slight modification to mine today when I had to remake the collet (don't ask)...

The idea came by accident when I was turning the aluminum for the collet and had that little step left. Basically those are 8-32 screws and I took a 3/16 endmill to the collet. This way the collet stays with the fixture but still has full range of movement.



Galaxy S3 on tapatalk

 

[Killswitch Engage]

I still like this fixture and I'm with Jon. We aren't removing much material. This has been as rigid as I need for what I do. If I were trying to do a group buy on action truing i would say it wouldn't be conducive to it but I'm not.

 

[300sniper]

Made a slight modification to mine today when I had to remake the collet (don't ask)...

The idea came by accident when I was turning the aluminum for the collet and had that little step left. Basically those are 8-32 screws and I took a 3/16 endmill to the collet. This way the collet stays with the fixture but still has full range of movement.

View attachment 15034

Galaxy S3 on tapatalk

Great idea.

 

[BigJW]

This is one I want to tag for future reference.