To glue or not to glue, Calfee

K

Kathy

Guest
My friends:

I built my first "centerfire" benchrest rifle almost 34 years ago.....

I owned a 40-X in 222 that had screwed together bedding......but I don't think I ever built a centerfire benchrest rifle that was not glued in...

At first we glued in the barrel, about 4 inches, starting about a half inch in front of the action face...

Then I went to sleeving, glued in...

Then to custome actions, glued in....

In other words, centerfire guns have been glued in forever it seems.....and still are...

Here's my thoughts about rimfire and a question......

I'm beginning to think we may be better off, in rimfire, maybe centerfire too, by screwing the bedding together instead of gluing......

I've been running some tests.....and have come up with some pretty outstanding conclusions......although, the school is still out on this subject....

One day we may find that gluing works best for rimfire too......maybe some of you have found gluing works best now...

My question: Should we be gluing our rimfires ?

Your friend, Bill Calfee
 
What would be the disadvantage? It seems that gluing would make the metal and the stock one unit and eliminate any possible movement, flex, etc. I don't think it's done a lot with rimfire, but that may simply mean that centerfire shooters focus more on the utility of the rifle than rimfire shooters do. I have an Anschutz 2013 that would probably benefit significantly from gluing, but Anschutz did not intend for it to be so. On the other hand, I have a couple of other rifles that seem fine with screwed together bedding. Still, what could be the disadvantage (we can assume proper workmanship)?
 
The only disadvantage

I can see is that we have been using the torque on the action screws for a long time to modify the down range performance of various ammunition. When you glue the stock in the actions screws may become only a decoration. Centerfire shooters have the option of load modification to modify performance and glue their actions to reduce the variable.
 
Bill,
I don't know which is best but I prefer to use screws on my rimfires. Just old fashioned I guess. I've never had a problem with getting them bedded correctly. My thoughts are that if it's done right it takes minimal torque to hold it together with 100% contact. No experience with glue-ins, but I think you still need to bed the action correctly before you glue it in.
Then again maybe a little tension pulling evenly down on the action into the stock helps kill vibration on an imperfect action? I don't know. But, I like the option of taking it out of the stock if need be, and the option of checking the bedding to see if the stock has warped between the screws and is putting tension in the middle, like sometimes happens.
 
I'm with Kent, I don't think there is any problem with a traditional bedding and using screws to hold the action in.

With gluing, i'm worried about the bond changing due to temp, solvents leaving into the glue, and the glue itself breaking down over time. Further, if there is a problem with a rifle, tradition methods of bedding allow for an easier inspection of the barreled action, when pulling it from the stock.

I also feel that there is a tiny bit of guessing when gluing in an action. You never can check the bedding one last time to see if it was done correctly.

I spoke with Alex Sitman over at Masterclass Stocks, and he seems to have excellent results with his standard pillar and bedding method, and I have followed his process for all the stocks I do.

I feel the only way to test this would be to take a proven rifle and try both methods for it, and see what happens.
 
Bill,
If you will pardon the intrusion, some time ago, I asked Lee Six the glue or screw question, and he said that he favored doing both, at the same time, a good pillar bedding job, glued in, with the screws torqued afterwards. I had never thought of that before, and thought that I would share the information, since it might be beneficial to your research. Lee and I were discussing centerfire, but why not rimfire too?
 
Glue vs. bolt....

What we are talking about here is a bolted joint - maybe the most common problem encountered in engineering. In spite of the fact it is on a benchrest rifle, on a Calfee thread, and I happen to shoot prone rather than benchrest, I'm still going to take a stab at it.

The stressed area of the glued joint is maybe 10 times the area of the action screw. The "length" (thickness) of the glue is roughly 1/1000 the bolt. If the glue line is thick then the length ratio of glue to bolt might be 1/100. The stiffness(modulus of elasticity) of the glue is approximately 1/15 the steel bolt.

It's movement between receiver and stock during recoil that is of interest. If a comparison is made between a normally glued joint and a finger tight action screw the glued joint would move about 1/1000 the bolted joint. If the glue line is thick, then the bolted joint would might still be only about 1/100 as stiff as the glued joint.

Now what happens when we tighten the action screws. Even if the glue line is thick the glued joint will move only about 1/10 what the bolted joint will. It will only be at very thick glue lines that the bolted joint might be stiffer. If the action screw could be made very short then bolted joints could be stiffer. Probably the biggest advantage of using both glue and screws is the ability to pull the glue line very thin.

Bolted joints must be tight and use short screws to maintain stiffness. This is why you must keep con rod bolts and head bolts and action screws tight. A scientific explanation for what is happening here - range stress and strain is lowered as we tighten a threaded fastener - it happens on rimfires, centerfires, everything. There is no need to make any distinction between types of guns or what they are used for.

I got to thinking after I posted this. Note we are talking STIFFNESS of receiver/stock attachment, not the STRENGTH!
 
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something else to consider

pacecil said:
Probably the biggest advantage of using both glue and screws is the ability to pull the glue line very thin.

!
Click to expand...
I have 5 fiberglass stocks and a laminated wooden stock that are aluminum pillared, screwed and glued. I only use the pillars and screws as a safely net so the screws are just snug, about 15 in/lb. The glue does the holding and recoil transfer of forces.

I have an email I got from a friend about 2 hours ago, his "just glued" just came loose and the stock dropped to the floor causing a dent in the stock. He was just changing barrels and the glue joint came loose. The glued joint was from one of the foremost custom stock makers (not Leonard).

Carry a glued-only in the trunk of a dark colored car in a hot climate and it WILL come loose...eventually.

I have two Leonard stocks that are glued only but those are on Stolle Pandas where there is 3 large flat contact surfaces. Even these do not get carried in a car trunk!!.
 
Glue or not to Glue

I am not sure if this information is true, but i am not willing to take the risk to find out!
before flying last year i had spoke to a number of shooters about flying with a rifle. I was told to loosen the bolts from the stock as the air pressure would effect it and could damage the rifle if the bolts are on as normal. if this is the case if you glue the system then how would this effect flying with a rifle?

I am going to WBC in Milan in two weeks and will still be sticking to the format that i was told, but i wondered Bill what your thoughts are on this?

Cheers, AndyD UKBRTeam
 
steve b. said:
I'm with Kent, I don't think there is any problem with a traditional bedding and using screws to hold the action in.

With gluing, i'm worried about the bond changing due to temp, solvents leaving into the glue, and the glue itself breaking down over time. Further, if there is a problem with a rifle, tradition methods of bedding allow for an easier inspection of the barreled action, when pulling it from the stock.

I also feel that there is a tiny bit of guessing when gluing in an action. You never can check the bedding one last time to see if it was done correctly.

I spoke with Alex Sitman over at Masterclass Stocks, and he seems to have excellent results with his standard pillar and bedding method, and I have followed his process for all the stocks I do.

I feel the only way to test this would be to take a proven rifle and try both methods for it, and see what happens.
Click to expand...

Steve, these days with the adhesives available, these are non-events. It you don't have problems with a PPC shot durring a winter league, the .22 in summer is staying there.
Bill, I'll tell you what, I'm beginning to become more of a believer in a quality BR wood stock-glued, can't prove it but the two I've done I'd swear resonate less.
 
Tim,

I hear what you are saying, but I'm not convinced that glued in action in our conditions, (+110 degrees) is gonna stay put over time.

But, it's really somthing that needs to be tested.

I myself have moved away from fiberglass stocks as well, and maybe with a wood laminate stock it really is a non-issue. But I also feel that a good standard pillar and bedded rifle is just fine as well, and gives up nothing to a glue-in.

s.
 
Steve, go over to the CF section and check with any of those south west guys. Not only do they not seem to have any issues but you gotta realize most folks these days "run" their shots, especially at 200yds or longer which means those actions get freaking hot after a couple relays.... for me this has been somewhat of an experiment but especially in wood the glue when properly done probably eliminates sneaky stresses. By the way, does it look like SCN might be saved?
 
Tim,

This ain't my first rodeo, thanks. We are talking of rimfire and not centerfire. If a person can't pillar and bed a rifle in traditional methods and not have it stress free, then they are using glue to side step a technical inability.

I don't agree with you, and until someone tests the same barreled action in both setups, it's still up in the air. Like I said in my first post, I follow what I learned from Sitman.

And no, SCN is toast, like many of the other companies the owner has been involved with.
 
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My friends

My friends:

Been a long day......I just turned on my machine and looked to see if anyone had responded.......

Thank you my friends......some great observations......

Have any of you folks taken a rifle, bolted together, found how it shoots, then glued it in and seen if there is a difference?

Your friend, Bill Calfee
 
Quote: "Have any of you folks taken a rifle, bolted together, found how it shoots, then glued it in and seen if there is a difference?"

That's exactly what I'm askin as well.

To take a proven rifle and ammunition, and test out both methods. Not just a few groups, but multiple cards over a few days.

I have not seen or read about a focused test like this done yet.

s.
 
Kathy said:
My friends:

Been a long day......I just turned on my machine and looked to see if anyone had responded.......

Thank you my friends......some great observations......

Have any of you folks taken a rifle, bolted together, found how it shoots, then glued it in and seen if there is a difference?

Your friend, Bill Calfee
Click to expand...

Yes, twice. This is not an easy comparison if the rifle was good before, but so far it seems better on average.
Steve, the centerfire example was used to answer you question about glue resiliency in heat.... when properly done, there are not any.
 
I have glued a good calfee #11 sporter in last year . and yes the glue made a good gun better
 
Glued and screwed is the only smart choice...............any other method is lazy and is only for those who want to be sloppy also rans...........Don
 
Bill,

I might be able to answer your question.
My Hall was bolted in and it won the RBA nationals in 06, I glued and bolted it in for 07 and won again. Surprisingly it shot on the same tuner setting after it was glued-in. I feel it’s more consistent target to target glued-in and with this rifle it’s the way to go.

Andy,
If you think there is enough of problem for your bedding, what will it do to ammo???

I have heard of alloy stocks cracking on flights but the air pressure in the hold is the same as the cabin and we are all in more danger from baggage handlers than air pressure.

Peter
 
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