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center22
06-18-2015, 11:26 PM
Today, I had an opportunity to check out a professional bedding job on a buddy's RFBR rifle. I was surprised to see that the Devcon coating was only about 1/32nd in thickness on average. A nice smooth compound layer, but in one area I could see the wood grain peeking through. The XIII action bolts directly on top of the aluminum pillars too. Is this considered normal or good workmanship?

PS: When I do a bedding job on my personal rifles, my goal is to put in at least a 1/8" to 3/16" layer of bedding compound. Lately, I began covering over the aluminum pillars with Devcon, so that the action does not make direct contact with the pillars themselves. Would like to hear from those that do this work professionally, or have experience at it. Thanks in advance, ... John


Posted this on another website as well.

Doodaddy
06-19-2015, 10:32 AM
If you take into consideration that there is shrinkage in the material when drying, thicker applications will likely experience a larger degree of shrinkage impacting the bedding fit. I would think the thinnest, functional layer would be best.

Boyd Allen
06-19-2015, 02:53 PM
Generally, I believe that pillars should not be metal to metal with the action, and that thicker is better for bedding compound, as long as what is used is something that will not deform under heat and pressure. This is not to say that the difference would be noticeable in many situations where the total quality of the build, quality of load workup, and manner and equipment used to shoot may entirely mask any difference. Accuracy is a weakest link thing, and I find that it is very common to find that shooters are worrying about some relatively small factor, and ignoring several larger ones. BTW the proper way to check a bedding job is with a dial indicator and magnetic base. How does your friend's check out using this method?

Doug
06-19-2015, 04:37 PM
Boyd - Nice Post!
Not everyone has a Dial Indicator but old farts like me have an Accurate Torque Wrench.
A 'Shade Tree Way' to check beading is to is to torque both front & back action screws to maybe 10 or 15 lbs.
Now put your finger at the front of the forearm and barrel and slowly loosen and tighten the action screws.
If you feel it rock in the bedding then you probably have a problem!
Actually you do not need a torque wrench - Think - Sung, Tighten & Loosen the action screws & feel for rock or roll!
Doug

PS: I am sure a lot will disagree with me but I never let the pillars touch the action & that includes any bedding on top of the pillars.

center22
06-19-2015, 04:55 PM
[QUOTE=Boyd Allen;758932]Generally, I believe that pillars should not be metal to metal with the action, and that thicker is better for bedding compound, as long as what is used is something that will not deform under heat and pressure. This is not to say that the difference would be noticeable in many situations where the total quality of the build, quality of load workup, and manner and equipment used to shoot may entirely mask any difference. Accuracy is a weakest link thing, and I find that it is very common to find that shooters are worrying about some relatively small factor, and ignoring several larger ones. [B]BTW the proper way to check a bedding job is with a dial indicator and magnetic base. How does your friend's check out using this method?[B]QUOTE]

Boyd,

I do own a dial indicator with the magnetic base, which I use when setting up work on a lathe. Would you kindly explain the process - "How one checks the bedding using it". Thanks.

My friend purchased this rifle used and has had issues with un-explained flyers/flippers plus overall accuracy for a long time. Attempting to assist him in tracking down the problem(s). Thanks, ... John

Boyd Allen
06-19-2015, 05:50 PM
Attach the magnetic base to the bottom of the barrel just in front of the forend and position the indicator so that it's plunger is contacting (slightly preloaded) the bottom of the forarm tip, and its travel is at a right angle to the bore, then do what Doug described. You don't want .000 movement because that is an indicator that something is not free to move, but you do want .002 or less. I have done the fingertip method, but for fine work, I do not think that fingers are as sensitive as a dial indicator, when it comes to very small movement. If you can feel movement with your fingers, you definitely have an issue that needs looking into. I Prefer to grip the stock and action, through the middle of the action with one hand while tightening and loosening screws with the other. Of course this is done with the rifle resting on its butt , with the barrel vertical. If you have the barrel leaning back at the muzzle a little as you loosen the front screw the weight of the assembly will pull it back from the bedding, which is why I hold things with my hand to support it enough so that this will not happen. Play with this a little and you will develop the necessary technique.

There are a couple of other issues that your friend should consider. Action screws should not touch the insides of their stock holes (or even be close to them. Also, a friend was recently driven a bit crazy by what turned out to be a scope issue. The scope is a 36x Leupold that had just come back from service with a note that they had overhauled the objective assembly. Evidently their testing did not include the turret assembly. Has your friend tried another scope. This would be a common source of his sort of problem. Getting back to bedding, there should only be one surface that acts as a recoil "lug" in a rifle's bedding. If there is more than one, the most suitable one should be kept for that purpose, and the rest trimmed back so as not to make contact. Depending on how it was done, bedding can look very good and not be.

center22
06-19-2015, 08:56 PM
Attach the magnetic base to the bottom of the barrel just in front of the forend and position the indicator so that it's plunger is contacting (slightly preloaded) the bottom of the forarm tip, and its travel is at a right angle to the bore, then do what Doug described. You don't want .000 movement because that is an indicator that something is not free to move, but you do want .002 or less. I have done the fingertip method, but for fine work, I do not think that fingers are as sensitive as a dial indicator, when it comes to very small movement. If you can feel movement with your fingers, you definitely have an issue that needs looking into. I Prefer to grip the stock and action, through the middle of the action with one hand while tightening and loosening screws with the other. Of course this is done with the rifle resting on its butt , with the barrel vertical. If you have the barrel leaning back at the muzzle a little as you loosen the front screw the weight of the assembly will pull it back from the bedding, which is why I hold things with my hand to support it enough so that this will not happen. Play with this a little and you will develop the necessary technique.

There are a couple of other issues that your friend should consider. Action screws should not touch the insides of their stock holes (or even be close to them. Also, a friend was recently driven a bit crazy by what turned out to be a scope issue. The scope is a 36x Leupold that had just come back from service with a note that they had overhauled the objective assembly. Evidently their testing did not include the turret assembly. Has your friend tried another scope. This would be a common source of his sort of problem. Getting back to bedding, there should only be one surface that acts as a recoil "lug" in a rifle's bedding. If there is more than one, the most suitable one should be kept for that purpose, and the rest trimmed back so as not to make contact. Depending on how it was done, bedding can look very good and not be.


Boyd,

You provided more helpful information than I would ever have anticipated. I'm sure this info will be of benefit to many others. My friends scope is a 45X Leupold and I'll have him try another scope. Thanks again for all the valuable advice. John

Boyd Allen
06-19-2015, 09:58 PM
You are quite welcome. I am glad to have been of some assistance.

Pete Wass
06-19-2015, 10:54 PM
I have found this to be a problem area, generally, with custom made rifles. Why Smiths are so skimpy on threads is a mystery to me. I have found the lack of threads on, particularly the front action screw to be a significant problem over the years. I cut two or three extra with a die when I think there could be a problem. One must also be sure the screws aren't bottoming out in blind holes as well, another area of concern. As bedding shrinks, screw length can be a problem.

P

tim
06-19-2015, 11:14 PM
As bedding shrinks???? I suspect Devcon is likely the most widely used compound. The published shrinkage is .06% there Pete. I'll give you a case of ELEY if it's possible for you to measure how small that is on a 1/4X28 screw thread , or any other popular size.

Doug
06-20-2015, 01:47 PM
Look closely at the Action screws!
Make sure they are CENTERED in the Pillars with some clearance & Not close to bottoming out in blind holes.
If you do not know how to check then I will try to explain further?

One further thought is to check horizontal movement with your Dial Indicator!
Vertical I can live with .003 but horizontal should probably be less than 002 - think nil.

Doug
06-20-2015, 03:17 PM
John - This might be a stupid question but did you do the old Dollar Bill test??

mwezell
06-20-2015, 04:16 PM
Pete, take the bet on the case of ammo, as assuming 1/4 inch thick bedding a shrinkage of .6 % would be 1.5 thou. You can measure that with a simple Chinese built dial caliper.
Dave

That's wrong. The shrink rate is .06%, or .0006" per inch. So a .100" thick layer will shrink by .00006" That's 6/100,000th shrinkage. I want a set of THOSE calipers.:D

Even still, a uniform thickness is what I like to see, so I mill to that approximate , but uniform depth.

tim
06-20-2015, 06:18 PM
Pete, take the bet on the case of ammo, as assuming 1/4 inch thick bedding a shrinkage of .6 % would be 1.5 thou. You can measure that with a simple Chinese built dial caliper.
Dave

I will, however, throw in a free 6th grade math class for you.

tim
06-20-2015, 06:23 PM
That's wrong. The shrink rate is .06%, or .0006" per inch. So a .100" thick layer will shrink by .00006" That's 6/100,000th shrinkage. I want a set of THOSE calipers.:D

Even still, a uniform thickness is what I like to see, so I mill to that approximate , but uniform depth.

So, as a pro, what do you figure, that's a screw head that goes from, say 12 o'oclock to about 12.01?
Hardly what I'd call a change in holding ability.

Boyd Allen
06-20-2015, 09:25 PM
On the dollar bill test, it has been obsolete for decades. A reliable barrel float, for accuracy work, requires much more room than that.

center22
06-21-2015, 08:42 AM
On the dollar bill test, it has been obsolete for decades. A reliable barrel float, for accuracy work, requires much more room than that.

Agreed ... recently pillar bedded my X3L barreled action into a Lidgard Zebrawood stock. When tested, I can easily slide five one dollar bills (when held together) between the barrel and stock channel. Brent does very nice work.

Haven't had an opportunity to test the bedding in my friends rifle, but hope to do so by Wednesday. Will update. John

Doodaddy
06-21-2015, 10:17 AM
On the dollar bill test, it has been obsolete for decades. A reliable barrel float, for accuracy work, requires much more room than that.

Why is that? Heat?

mwezell
06-21-2015, 11:32 AM
Why is that? Heat?

Particularly with wood...it moves. Also, as we know, the barrel moves when fired, as do scopes. Ever seen a scope very close to a barrel? I've shown customers the mark on top of the barrel left by the scope and barrel coming into contact with each other, and still be able to slide a $ bill between the two, freely. The look on their face is one of enlightenment. The mark looks like a small wear mark. That has to be hard on optics but also tells us that stuff moves when a 60,000psi explosion happens in there.:eek:

Obviously, the person claiming on another site that the muzzle can only move about a half thou has never seen this and it raises question to his claim.

Boyd Allen
06-21-2015, 12:08 PM
If I am floating a wood stock, and want to preserve the appearance of some degree of fit, I use what amounts to the thickness of a matchbook cover on on the sides, with more underneath, and pay close attention to the gap being of consistent width along its length and on both sides. I also try my best to keep the top edges of the barrel channel sharp. For pure target work, I like quite a bit more room, particularly if the action is glued in, where clearance to move the largest probable shank diameter and length forward in the stock as the barrel is removed is required.

Doodaddy
06-21-2015, 12:39 PM
Particularly with wood...it moves. Also, as we know, the barrel moves when fired, as do scopes. Ever seen a scope very close to a barrel? I've shown customers the mark on top of the barrel left by the scope and barrel coming into contact with each other, and still be able to slide a $ bill between the two, freely. The look on their face is one of enlightenment. The mark looks like a small wear mark. That has to be hard on optics but also tells us that stuff moves when a 60,000psi explosion happens in there.:eek:

Obviously, the person claiming on another site that the muzzle can only move about a half thou has never seen this and it raises question to his claim.

I've personally never liked the aesthetics of seeing a barrel channel large enough to encompass two barrels like I see on many benchrest rifles. I always chalked it up to them wanting absolute clearance no matter what barrel they swap to and that made plenty sense to me. I suppose it could be easy peace of mind with the barrel floating since there would be no question that a quarter inch of space is sufficient. :p

My bench rifle looks to have about thirty thousandths of an inch clearance between the channel and the barrel. Is that enough in your experience?

I'm not shocked about the scope movement. I've never had one so close to the barrel though.

mwezell
06-21-2015, 01:24 PM
I've personally never liked the aesthetics of seeing a barrel channel large enough to encompass two barrels like I see on many benchrest rifles. I always chalked it up to them wanting absolute clearance no matter what barrel they swap to and that made plenty sense to me. I suppose it could be easy peace of mind with the barrel floating since there would be no question that a quarter inch of space is sufficient. :p

My bench rifle looks to have about thirty thousandths of an inch clearance between the channel and the barrel. Is that enough in your experience?

I'm not shocked about the scope movement. I've never had one so close to the barrel though.

I like to use a nice, consistent .030" on hunting rifles, but on BR guns, I don't mind there being more. On fiberglass stocks that I know I'm going to paint, I use heat shrink tubing on the barrel and bed it into fiberglass in the barrel channel to achieve the consistent gap...when that size gap is what I'm after. It cures fast, works and sands easily and does the job nicely. Wood is more tedious unless done on a cnc mill to follow the contour of the barrel. Some people feel the extra space aids cooling. I'm sure it does to some degree but I'm not sure its a substantial enough amount to be significant.

Some people also judge the craftsmanship by the wood to metal fit along the barrel channel. As Boyd has mentioned, that theory is out dated if your primary goal is how it shoots. IMO, it's harder to maintain an even, small gap than to make it seem seamless, as the top edge is what matters most where it meets the metal. It could be just about anything below the stock line, where it's hidden.

To each their own, but I much prefer the stock never touch the barrel. Exactly how much gap that takes is dependent upon the barrel and stock, but .030 is what I consider to be a safe amount without looking bad.

Here's a pic of a hunting stock with .030. It'll look better when I finish the barrel, as it's still in the white. The gap will be less apparent when the metal is dark.
16287

Doug
06-21-2015, 03:57 PM
Your original question was does "Thickness Matter"
NOPE - Only Quality!!


Today, I had an opportunity to check out a professional bedding job on a buddy's RFBR rifle. I was surprised to see that the Devcon coating was only about 1/32nd in thickness on average. A nice smooth compound layer, but in one area I could see the wood grain peeking through. The XIII action bolts directly on top of the aluminum pillars too. Is this considered normal or good workmanship?

PS: When I do a bedding job on my personal rifles, my goal is to put in at least a 1/8" to 3/16" layer of bedding compound. Lately, I began covering over the aluminum pillars with Devcon, so that the action does not make direct contact with the pillars themselves. Would like to hear from those that do this work professionally, or have experience at it. Thanks in advance, ... John


Posted this on another website as well.

center22
06-22-2015, 01:08 PM
Your original question was does "Thickness Matter"
NOPE - Only Quality!!

If that is so, ... What is your interpretation of "Only Quality"?

Doug
06-22-2015, 03:57 PM
I use the Duck Test!
If it looks like a duck, swims like a duck, and quacks like a duck, then it probably is a duck!

Maybe Read the Above posts to see if you have a Duck

Pete Wass
06-22-2015, 06:34 PM
As bedding shrinks???? I suspect Devcon is likely the most widely used compound. The published shrinkage is .06% there Pete. I'll give you a case of ELEY if it's possible for you to measure how small that is on a 1/4X28 screw thread , or any other popular size.

How do you know all Smith's use the same compound to bed with? I have had one rifle glued in come loose because the bedding shrunk and seen two or three others over the years do the same. I have personally had two rifles that came to me from Smiths with two or three threads on the front Action screw, both of which eventually did not hold the action fast to the bedding and became teasers, accuracy wise. I believe what I experience, not what someone writes in a paper. Wouldn't hurt nothing for Smiths to put 7 or 8 threads on an action screw, would it?

Pete

tim
06-22-2015, 09:07 PM
How do you know all Smith's use the same compound to bed with? I have had one rifle glued in come loose because the bedding shrunk and seen two or three others over the years do the same. I have personally had two rifles that came to me from Smiths with two or three threads on the front Action screw, both of which eventually did not hold the action fast to the bedding and became teasers, accuracy wise. I believe what I experience, not what someone writes in a paper. Wouldn't hurt nothing for Smiths to put 7 or 8 threads on an action screw, would it?

Pete

Welllll, long story short, how the hell do you know why those glue in's failed? Could have been improperly
catalyzed compound, old compound, or more likely guns the have gone through a lot temperature change.
That said, most modern compounds have similar shrink rates, rarely more than 1%.
2 or 3 threads are less than ideal but that action ain't goin anywhere unless they used silly putty.

Pete Wass
06-23-2015, 07:51 AM
Welllll, long story short, how the hell do you know why those glue in's failed? Could have been improperly
catalyzed compound, old compound, or more likely guns the have gone through a lot temperature change.
That said, most modern compounds have similar shrink rates, rarely more than 1%.
2 or 3 threads are less than ideal but that action ain't goin anywhere unless they used silly putty.

if the screw threads bottom out before they are able to fasten the action to the bedding - - well, I guess you could see that, eh? In the case of the shrinkage, if a rifle performs well initially, then , over time does not and it is found that the front action screw is thread binding, couldn't one assume that it is the shrinkage of the bedding that caused the problem? As I've said, I've seen this happen more than once and with other people's rifles as well as my own.

Pete

Pete Wass
06-23-2015, 07:59 AM
Agreed ... recently pillar bedded my X3L barreled action into a Lidgard Zebrawood stock. When tested, I can easily slide five one dollar bills (when held together) between the barrel and stock channel. Brent does very nice work.

Haven't had an opportunity to test the bedding in my friends rifle, but hope to do so by Wednesday. Will update. John



:D

Pete

center22
06-23-2015, 09:13 AM
:D

Pete

Hello Pete,

I only had "five" one dollar bills in my wallet, for testing. This hobby has kept me extremely poor. LOL

Hope you and your significant other are doing well. Right now, it's "hot as hell" in south Florida ... and I've lived here for 51 years! Can't wait for weather that resembles winter. :rolleyes:

All the best, ... John

tim
06-23-2015, 04:04 PM
if the screw threads bottom out before they are able to fasten the action to the bedding - - well, I guess you could see that, eh? In the case of the shrinkage, if a rifle performs well initially, then , over time does not and it is found that the front action screw is thread binding, couldn't one assume that it is the shrinkage of the bedding that caused the problem? As I've said, I've seen this happen more than once and with other people's rifles as well as my own.

Pete

Pete,
You're the guy that can fit and chamber a rimfire barrel. You, i assume can also use a dremel tool and cut 1-2 threads off a screw. This really ain't complicated.
Me, that's why I use a guy like Tom Meredith. Been doing it almost 40 years. Great bedding, perfect screws every time.:confused:

Pete Wass
06-24-2015, 08:03 PM
Pete,
You're the guy that can fit and chamber a rimfire barrel. You, i assume can also use a dremel tool and cut 1-2 threads off a screw. This really ain't complicated.
Me, that's why I use a guy like Tom Meredith. Been doing it almost 40 years. Great bedding, perfect screws every time.:confused:

I agree with you, His work is superb. I have fit an cut several barrels Tim, all have worked so far. I have also lapped a couple of bad ones that now shoot pretty well also. Some think it can't be done but guess what - - -

Pete

center22
06-25-2015, 01:48 PM
Update:

In the early morning hours, before our club practice match yesterday, I had an opportunity to set up a dial indicator on my friends rifle in an attempt to check the bedding quality. I was instructed to hold the rifle upright, during the testing procedure, but I had difficulty with the large magnetic base sliding downward and not holding well on the S.S. barrel. So I altered my testing procedure somewhat, by setting the rifle upside down in my wooden homemade cleaning cradle. With the front of the stock resting on each side of the yoke, at an upward angle, with the barrel suspended freely below. I then affixed the magnetic base to the barrel just forward of the stock. The dial indicator was adjusted to contact the center of the stock, about an inch back and the needle set to zero.

I then had my friend use his screwdriver style torque wrench to loosen the rear screw and re-torque it again to his normal setting, which was about 25 inch pounds. The needle hardly moved and when re-torqued it remained at zero. Things were different with the front action screw. I asked him to loosen it gradually until it moved around .015" and had him stop. At that point, I asked him to re-torque the front screw to 25 inch pounds and the dial indicator returned to zero as well. With this preliminary test, the bedding quality appeared good to us, but I'm not certain this test alone was valid. Because wood has a tendency to move (shrink or swell) with heat and humidity, and my friends rifle had been stored in an air conditioned environment over night.

Recommended he return his 45X Competition scope back to Leupold to have it thoroughly checked out. He told me that when he first got the scope, he did attempt to adjust the turret knobs to zero them out. Unlike older Leupold scopes that have three small set screws to perform this procedure, the Competition models are much more challenging and problematic in this area.

To see if my friends problems could be related to poor shooting skills (LOL) I suggested that he shoot my most accurate rifle in the match that day. He agreed to the offer, and was shooting my Rocky River Barn rifle. With ten unlimited shooters competing, my friend placed 2nd in the aggregate, kicking my butt by 10 points (3rd place) and a bunch of X's in the USBR match. So, ... we therefore have proven two things, it is not his poor shooting skills, nor his rest setup, that are causing flyers/flippers and poor accuracy with his rifle. In the mean time, he is going to put a 36X Sightron scope on his rifle. John

Boyd Allen
06-25-2015, 02:14 PM
Revised because I skimmed your post too quickly and did not pick up that it was your rifle and not his that he shot so well with.

You seen to have let the tail wag the dog when attempting to test his rifle's bedding. If you need to, tape the base to the barrel to make it more secure than the magnet alone. Basically you did not do the test properly. One of my someday projects will be to make a clamp setup that resembles a low torque rifle vise, to clamp the indicator stand rod and top to a barrel.

Pete Wass
06-25-2015, 03:38 PM
Update:

In the early morning hours, before our club practice match yesterday, I had an opportunity to set up a dial indicator on my friends rifle in an attempt to check the bedding quality. I was instructed to hold the rifle upright, during the testing procedure, but I had difficulty with the large magnetic base sliding downward and not holding well on the S.S. barrel. So I altered my testing procedure somewhat, by setting the rifle upside down in my wooden homemade cleaning cradle. With the front of the stock resting on each side of the yoke, at an upward angle, with the barrel suspended freely below. I then affixed the magnetic base to the barrel just forward of the stock. The dial indicator was adjusted to contact the center of the stock, about an inch back and the needle set to zero.

I then had my friend use his screwdriver style torque wrench to loosen the rear screw and re-torque it again to his normal setting, which was about 25 inch pounds. The needle hardly moved and when re-torqued it remained at zero. Things were different with the front action screw. I asked him to loosen it gradually until it moved around .015" and had him stop. At that point, I asked him to re-torque the front screw to 25 inch pounds and the dial indicator returned to zero as well. With this preliminary test, the bedding quality appeared good to us, but I'm not certain this test alone was valid. Because wood has a tendency to move (shrink or swell) with heat and humidity, and my friends rifle had been stored in an air conditioned environment over night.

Recommended he return his 45X Competition scope back to Leupold to have it thoroughly checked out. He told me that when he first got the scope, he did attempt to adjust the turret knobs to zero them out. Unlike older Leupold scopes that have three small set screws to perform this procedure, the Competition models are much more challenging and problematic in this area.

To see if my friends problems could be related to poor shooting skills (LOL) I suggested that he shoot my most accurate rifle in the match that day. He agreed to the offer, and was shooting my Rocky River Barn rifle. With ten unlimited shooters competing, my friend placed 2nd in the aggregate, kicking my butt by 10 points (3rd place) and a bunch of X's in the USBR match. So, ... we therefore have proven two things, it is not his poor shooting skills, nor his rest setup, that are causing flyers/flippers and poor accuracy with his rifle. In the mean time, he is going to put a 36X Sightron scope on his rifle. John

Uneven bedding? If the bedding is flat, why would the barrel rise .015"?. I have seen a fair number of Leup Comps that had to go back. I guess for the difference in cost between them and a March they are a pretty good value but I would as soon have a Weaver 36 X I guess. They seem to be able to handle Rimfire guns OK. 30 Cal HBR and VFS rifles will tear them up. I have a Brackney frozen Leup Comp 40X and I trust it. It has crosshairs only, which I don't like much.

Pete

Boyd Allen
06-25-2015, 03:42 PM
Note my revision to my previous post.

Pete Wass
06-25-2015, 03:46 PM
Hello Pete,

I only had "five" one dollar bills in my wallet, for testing. This hobby has kept me extremely poor. LOL

Hope you and your significant other are doing well. Right now, it's "hot as hell" in south Florida ... and I've lived here for 51 years! Can't wait for weather that resembles winter. :rolleyes:

All the best, ... John

The Spousal Alternative is doing OK. A couple of minor skeletal related issues since we got back but otherwise fine and dandy. We are having an interesting Spring/Summer here in Maine, so far. Gets up to 80 or so during the day and back to the low 60's in the evening. I am finding I much prefer 70 to 75 in the evening and don't mind 90 any more during the day :). I'd prolly do ok down by you, eh?


Best wishes,

Pete

Doug
06-25-2015, 03:50 PM
I tried using a magnet to hold my dial indicator to the barrel & indicate off the stock with not much luck!
The solution was to clamp the Dial indicator to the stock & indicate off the barrel if that makes sense?
I put my rifle in the rest like I would shoot it!!
Next I took a 4 inch 2X4 and drilled a 1 1/8 hole and split it down the center.
I clamped this over the stock at the forearm so the barrel free floated under.
Next I clamped my dial indicator to this block & indicated on the barrel just in front of the forearm!

PS I have two simple blocks - one 7/8 for my sporters and 1 1/8 for my heavy guns.
Also the gunsmith who told me about this test measured with the rifle vertical.
For many reasons after testing I felt this was invalid.

Boyd Allen
06-25-2015, 04:15 PM
I am not sure that you guys get what is being tested for, and why it should be done in the vertical position.

Pete Wass
06-25-2015, 04:54 PM
The bedding should be flat front to rear and rear to front? It would seem to me that ..015" of compression over the rear pillar is excessive, of course a little bit back there would be exaggerated on the other end but .015" ?

Pete

center22
06-25-2015, 05:11 PM
I am not sure that you guys get what is being tested for, and why it should be done in the vertical position.

Somewhere in my workshop, I have a much smaller and lighter attachment for a dial indicator than the massive one I tried using. Problem is, ... I have to find it! :(

center22
06-25-2015, 05:40 PM
The bedding should be flat front to rear and rear to front? It would seem to me that ..015" of compression over the rear pillar is excessive, of course a little bit back there would be exaggerated on the other end but .015" ?

Pete

I can now relate to why the "action bedding" must be tested in a vertical position only, with the rifle butt being supported on a sturdy surface. The rear tang screw and pillar, are "IMHO" the weakest point in the action and bedding. All three of my 10X actions use "three action screws" and pillars. I drill and tap for a third action screw (1/4X28 TPI) @ 1.750" back from the front screw, on center. This may be considered overkill by many, but it has worked well for me. I only wish they came tapped this way from the factory.

MIKECAMERON
06-26-2015, 10:41 AM
The bedding should be flat front to rear and rear to front? It would seem to me that ..015" of compression over the rear pillar is excessive, of course a little bit back there would be exaggerated on the other end but .015" ?

Pete

Pete go back and reread the mans post the rifle was UPSIDEDOWN in his cradle with the barrel hanging free under, why would the barrel,magnetic indicator base, and action NOT move, and .015 isn't that much with all the weight of the barrel and action and indicator.When he loosened the rear bolt it didn't move which is what should happen but when he loosened the front it moved as it should have. It really wasn't a good way to do the test(no disrespect John), the test is properly done with the gun right side up.
MC

center22
06-26-2015, 06:15 PM
I located my smaller dial indicator, which has the ability to clamp to the barrel. I tested one of my rifles (XIII/Stith/Mullerworks) with it and the front screw showed .0035" of movement when loosened. The middle screw had movement of .001" as did the rear action screw. When each screw was snugged up, the indicator dial returned to zero.

On my newer rifle (X3L/Lidgard/Mullerworks) there was NO noticeable movement at all on the dial indicator, when loosening and tightening each screw. This may be due to the fact that the Zebra wood stock is very hard/dense. Only a guess.

Tomorrow morning we have another USBR match at the club. Will try the new dial indicator setup on my friends rifle. But now he wants to keep shooting my rifle. LOL John

Pete Wass
06-27-2015, 08:39 AM
I can now relate to why the "action bedding" must be tested in a vertical position only, with the rifle butt being supported on a sturdy surface. The rear tang screw and pillar, are "IMHO" the weakest point in the action and bedding. All three of my 10X actions use "three action screws" and pillars. I drill and tap for a third action screw (1/4X28 TPI) @ 1.750" back from the front screw, on center. This may be considered overkill by many, but it has worked well for me. I only wish they came tapped this way from the factory.

Some of the custom actions over the years do or did come with three action screw holes but, as I recall, the center screw tended to upset the vertical plane of the bedding alignment when tightened.

I don't think the .22 Rimfire rifles require a whole lot in the area of bedding, not like high recoiling CF rifles do. I have seen too many .22 rifles, factory Anschutz' and the like, with no bedding shoot pretty dern well. It's one of those check off things to make sure everything has been covered. Sort of like all the fuss over being able to bend a Turbo action by pushing down on the rear tang. If the action is screwed down to good bedding or even a flat surface, how ya gonn bend it? A lot of this stuff gets blown out of proportion is all but it ain't good to bend actions with un-even bedding. Makes them bolts hard to open and close, eh? :p

Pete

Doug
06-27-2015, 08:45 AM
John
From your pictures It looks like you are indicating on the front end measuring horizontal movement & not vertical???
You need to indicate on the top or bottom of the stock for a valid check.
With that being said any horizontal movement would indicate a problem.

Pete Wass
06-27-2015, 09:50 AM
a gap under the rear of the action, if they tighten the front action screw, if there they have a bow in their bedding. could probably check it with feeler gauges or ya five dollar bill.

Pete

center22
06-28-2015, 11:39 AM
John
From your pictures It looks like you are indicating on the front end measuring horizontal movement & not vertical???
You need to indicate on the top or bottom of the stock for a valid check.
With that being said any horizontal movement would indicate a problem.

Doug,

The indicator fixture I'm using in the photos has a traverse bar about five inches long. One side of the bar was centered under the stock, about 1/2" back from the front edge. The other end of the bar pushes upward on the indicator pin (beveled head) to produce a reading on the dial. If I get a chance I will take a close up photo of the fixture and post it here.

Didn't have an opportunity to test my friends rifle with the new indicator setup. He again took 2nd place (eight unlimited competitors) in our club USBR match with my better rifle. His 45X scope was shipped back to Leupold.

John