OK, Folks: Here we go. I am not a highly opinionated or
stubbornly fixed in attitudes...I'm over 60 years old & have played around with guns & hunting since about 13 years old...I am still learning & am non-alsheimers afflicted.
Now, Mr. Rocky Gibbs of the Gibbs cartridge designs once said: "The primary purpose of bedding is not to force the barrel in any direction, but merely to cradle it very gently to prevent excessive vibrations."..."None of my rifles have shot as well with a full floating barrel as when they are gently supported at the foretip." Now I realize that free floating barrels with a bit of bedding at
the receiver is the vogue now...but I think its mostly a quick & dirty solution. The gunmakers love it, because its so easy & inexpensive. Here's the debate question: I bed all my rifles full barrel length, plus receiver section.
In other words, the entire barrel channel is glass bedded supported like a glass liner...also the receiver area. ALL my rifles have shot better this way than not. This means vs.
"free floating" barrel method. I don't know why this is not good. The most accurate rifle I ever had, had very precise inletting & barrel channel fit to perfection all in wood, no glass bedding. It had sporter weight barrel & had a witnessed 0.93 inch, 5 shot group at 300 yards at the range (me shooting). Why does the entire barrel channel lined with glass bedding not be as good? (I subsequently lined the said rifle with glass bedding; the entire barrel channel & it shot just as good, the same). Point is: I think from my experience that glassing in the entire barrel length is superior, than just the receiver & free floating the barrel. I throw this topic out, because in my experience (I've done before & after tests) the barrel bedding full length is better. Now, if I only made a couple tests...I would throw it out as unreliable...but not when it is 100% on very many rifles of different makes & styles (all bolt actions though). Comments welcome...
Thanks, Tom

Tom, I too glass bed full length.......from one end of the action to the end of the barrel channel except that I wrap the barrel in a layer of electrical tape before setting the barreled action in the bedding compound.

After curing.....a day or two....I remove the barreled action and remove the tape and the barrel is "free floating" but the amount of gap is so small that it's almost not visible. Usually have to scrape a small amount of glass from the channel anyway.

Many years ago I bedded (without acraglas...just hand inletted) a M-70 .225 Win in a piece of claro and I can assure you that the fit was horrible....it was among my first stockings ever......and I had a very lot to learn but for reasons I'll never understand it shot very well.....I don't even remember if the barrel was floating!!! I say this only to point out that if it works accept it and move on.....

Remington machines a "bump" in the tip of their wood stocks to apply upwards pressure on the barrels and they've had some marvelously accurate rifles right out of the box!!! I (and others I know) remove those things every time they come in for accurizing......and always improve the accuracy.

Savage rifles are notoriously accurate.....and the last one I saw was free floated.....are they all????

All I can say is that glass bedding the action and free floating the barrel works for me.

Good topic.....I hope to see lots of replys.

Post deleted by ASS_CLOWN

Tom,
As a carpenter and shipwright for much of my mis-spent youth I know how much wood moves with moisture content variation. It may be hard to gently cradle the barrel without altering point of impact due to humidity changes unless using sealed laminated or synthetic stocks. My personal choice is accuracy (hits where you aim) over precision (smallest group) for a hunting rifle so I lean toward full float. But may change my mind if there was a twenty dollar bet on smallest group.

ASS_CLOWN

Quote:

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The short (and safe answer for me) is YES there is logic to bedding. This is a forced vibrations problem, and as such can be logically solved. The difficulty lies in understanding the dynamic stiffnesses of barrel, receiver, and stock. Basically, you want to keep the barrel away from a natural frequency < !--color-->

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We're going to have conflict on this point sir.....It's my contention that we want the barrel free to vibrate unimpeded.......and to do so the same every time.

I'm listening again......

AC, what does it mean to keep the barrel away from a natural frequency? Is that something that you can determine somehow--I'm just clueless, and interested. I have read that a floated barrel shoots better groups and is less precise. Is that backwards? I have always been advised to make sure the action is solid as possible but the barrel floated--I guess the point of the thread is which is really 'best'?

In a Hunting rifle a consistant rifle is more important than a hyper-accurate rifle. With a full forearm bedded rifle unless it is incredibly stiff as soon as you put some sling or bipod pressure on it is going to change point of impact even if you manage to seal the wood to were moisture never changes POI. A free floated barrel in a wood stock has a more trustworthy point of impact. Sealing and careful selection of wood can help a lot but doesn't always end POI shift.
Give me a 1 MOA rifle that shoots to the exact same spot year round no matter what the humidity, temperature or sling pressure over a 1/4 MOA rifle that shifts POI when it rains......DJ

From a structural stiffness standpoint, I would think you want a symetrical system. Grounding only a portion of the cylindrical surface is not symmetric support. The barrel is free to move upward and not downward, and the lateral displacements are subjected to a different grounding stiffness also. Certainly, one could come up with a repeatable dynamic behavior, but why would you make a case for an unsymetric foundation? If stiffness is required, increase the barrel stiffness around the entire circumference.

I changed a 303 British SMLE from a wondering POS into a 300 yard bet winner by making the from stock piece float from the chamber forward. It wasn't pretty, but it worked for me. Because of its uglyness, getting someone to bet was not just easy, had to drive away those wanting part of the action.

I am not trying to say that free float is the way to go, more that consistency has more to do with it than other factors.

Action bedding gives a baseline consistency, barrel bedding and stock sealing help also.

JMHO of course.

Full length bedding can work pretty well and I have had some rifle which I bedded full length which were quite accurate. They were not as accurate however as properly bedded rifles with barrels which did not touch the stock. There have been some exceptions. Ruger #1's, for instance, have always worked better for me with contact. I once barreled a 270 (mauser action) and bedded it finto the wood with contact all the way up. The rifle shot very well and 3 shot groups under an inch were common. The point of impact and the level of precision varied from day to day however as did the point of impact and, to me, it would have been unacceptable although it would have always have hit a deer just fine.
Early on in the BR game gunsmiths used fully bedded rifles and occasionally shot some groups which were very small even by today's standards. It has to be noted that they seldom shot great aggregates though and a rifle which was hot one week was often a loser the next. In recent years I have seen a couple of rifles which tried some sort of forend bedding to try to tune out vibrations which were causing vertical stringing. They were semi-successful and occasionally won. For the most part though, all BR rifles are floated and the actions bedded (and usually glued in).
I wish all of my competitors at the "F" class matches would full length bed their rifles. That would certainly give me the sort of edge I need to be assured of winning! Years ago, most, if not all, long range rifles were fully bedded. A rifle built that way today wouldn't win squat!
Ultimately, if one likes his rifles full length bedded, he should do that. It will probably work out OK. It won't be the best way of doing it though.
By the way, I have always felt, if a rifle needed to be bedded on the forend to shoot well, the action bedding was imperfect and the barrel bedding was required to compensate for the shortcomings of a poor action bedding job. Regards, Bill.

I can confidently state that I have no direct knowledge that would resolve this issue. But, a couple of a second-hand ideas, from good sources:

Harold Vaughn, in his book, said that it is devilishly difficult to make a really rigid threaded joint, such as the one where barrel meets receiver. Putting upward pressure on the barrel pre-loads the joint, and tends to reduce fliers as the barrel heats. He also said that he found no benefit to accuracy from bedding.

My opinion is that bedding does offer the benefit of getting you closer to the same POI after you take the receiver out of the stock and put it back.

Tom,
I could not agree with you more. On any stock that I build, I bed the barrel first in wood and then I shoot it to see how it performs. If it shoots well, I remove a whisker of wood and essentially do as you said, bed the barrel channel. I use clear epoxy resin and also use it in the inletting to seal it well. I build hunting rifles and I am not trying to eke out every minute tiny bit of accuracy. It just isn't necessary in a hunting rifle.

It is important to use a good finish on the exterior to seal that as well. There are a lot of modern oil finishes that do that despite what you may see or read on here.

Maybe this is the appropriate part of the thread to make a few points...



1. It has always been my experience that the quality of the bedding, rather than the theory of bedding, is the most productive of both accuracy and consistency. In other words, well-done bedding works better than poorly done bedding, regardless of the approach used.



2. Whether the barrel is floated is NOT always the important question. Though the vast majority of Short-Range BR shooters DO float their barrels, there is a surprising number of Long-Range BR shooters who solidly bed the barrel in a "barrel-block" and float the ACTION, with equally good results.



3. There is logical and apparently sound theory behind each method of bedding, but I know of no definitive proof of any one theory being superior to another.



Personally, I have owned rifles of outstanding accuracy and reliability, and others that were real dogs, with all of the following types of bedding:



A. No expoxy at all, barrel also bedded

B. No expoxy at all, barrel free-floated

C. No epoxy at all, barrel floated except for pressure at or just behind the forend tip

D. Epoxy bedded at action, with barrel channel full length epoxied.

E. Epoxy bedded at action, with barrel full-length floated

F. Epoxy bedded at action with barrel free-floated except for epoxy pressure point(s) at or just behind the forend tip

G. Barrel epoxy-bedded into a barrel-block, which was in turn epoxy-bedded into the forend, with the rest of the barrel and all of the action free-floated.

H. Action & barrel bedded in strips of foam rubber which in turn, were inletted into the stock.



Those experiences leave me to fall back on the configuration and the quality of workmanship of the entire rifle as the most important variable. I have developed a healthy suspicion of any (EVERY) approach that claims to be exclusively THE right one.



I suspect that if there was any method that was clearly THE best, it would by now be in common use by everyone.



Best wishes to all,



Alberta Canuck

In this discussion/topic...I agree with Grandview...as to
vibrations, etc. when I started on full bedding stocks...
a point was made that full barrel bedding, basically glued in with Acraglass or equivelent made a sporting weight barrel basically stiffer..attaching it as part of the stock,
surely there would be some dampening..with the barrel extending past the stock with most vibration...like if you shoot a rifle with the barrel only 14 inches, say a Lone Eagle type...and the barrel quite heavy...also benchrest
rifles with heavy barrels...much less barrel vibration &
quite a big difference in accuracy. My contention is a
similar, but not identical happening occurs if you stiffen the barrel with full bedding..it works for me. I'm only being pragmatic in this discussion...I don't have a vibration engineer type to list graphs, etc. But heck, what works, works.

Thanks for inputs!

Best Regards, Tom

I've bedded a boat load of rifles over the years and they still never fail to confound me every once in a while. First, I'm a firm believer in two point bedding for factory rifles. The tang area and the recoil lug, and the first few inches of the barrel, with the remaining barrel floated. This has produced some outstanding groups and consistency. Compare that to the new Ruger synthetic stocks that are in the same class as Ramline, and have all kinds of pressure points on the action. To look at them they look like there's no way they could shoot accurately. But, I have two that shoot extremely well as long as you don't put any pressure on the bottom by way of the sling swivel. On one of them I free floated the barrel and it shot even better without the worry of the sling affecting it. Those plastic stocks, don't fit all that well and I can't believe they don't flex to match the contour of the action, but they work.
Also, I've taken the standard Rugers with walnut stocks and they've shot amazingly well with the factory pressure point on some, and others needed to be floated.
All this is to say that a rifle, any rifle, is a book unto itself and the search for it's top accuracy cannot be placed in any one method, but is a search for the best method.
Since most of my rifles are hunting guns, I don't like bedded barrels, as this tends to change the point of impact with weather conditions unless the stock is super stable, which isn't the norm.
So, it's experiment, experiment, experiment, or accept the accuracy as-is for hunting, which is normally good enough for the shooting we do. I'm a perfectionist so I tinker with my rifles until they shoot really well.

Vapodog: Thanks for reply...Savage bolt rifles are quite
accurate, true...however, I took a Savage 112 I
think...the varmint model anyway, glass bedded
fully, taking away the free floating feature...
is was in .22-250...and "fire lapped" the barrel
too. I won't tell you how good the accuracy was
because it was simply incredible...and many won't
believe it...before there were 1/2 inch groups...
it went much smaller after my "accurizing"!
But if someone asked me the most accurate standard
factory rifle...I'd have to say "Savage" without
any qualms whatsoever...maybe I should ask them?!
But my 'method' did improve on the Savage too!

Best regards, Tom

Re. Bajabills reply regarding symetrical bedding...in a sporting weight rifle for hunting purposes...perhaps a
bull barrel stiffness should be more accurate...but I don't want the weight involved...so just bed the barrel channel.
I think it achieves more stiffness...enough to improve the
accuracy. I also agree with some replies that free floating works OK,,,BUT, I have taken free floating rifles &
full length glass bedded them,,,removing the free floating & accuracy had improved, so why that then? Like Shakespere
said...more things in heaven & earth that are dreamt of in your philosophy...I believe more in results & pragmatism than theories...if I get good accuracy from my method,,,I'm happy with it. But, I'll tell you I had the bench rest boys muttering to themselves when I pulled in my 300 yard target with my 'accurized' .25-06 & a 0.93 inch five shot group at not 100, but 300 Yards at the Cody Shooting Complex, not with any heavy rifle, but a sporter .25-06. A Mark X Mauser & Douglas Premiumn Barrel, 24 inch. And, of course, my fully bedded glassed in barrel! Maybe an accident? Don't think so, its worked well for me on most any rifles I've applied it to...maybe not as good as said
example...but always has been an improvement.
I'm glad to hear some supporters replying! Thanks, Tom

Hi: Reply to Bobby. I've found I have had no problems with wood stocks moving about once I have the exterior pretty much sealed in with a good stock finish, and the
receiver section...then the glass bedding of the barrel channel full length effectively seals that too. So the wood stock just doesn't move about. I would think with a precise wood fit in the barrel channel as good as it may be, and the wood fully cured...there is more chance for the wood to move about than if it is sealed by glass bedding.
Where is the mositure going to get in if sealed?
I once had an exhibition grade Myrtlewood stock made for a cutom FN Supreme Mauser...the gunsmith insisted the wood be completely sealed in by Roberts Wood Products so the wood couldn't move at all. It was sealed & never moved at all.
So, its to say that glassing in the barrel channel does a sealing job...Tom

One thought on my comment about symmetry

Im backpeddling perhaps. If it were symmetric within reason (infinitesimally it would not be however) then we could have primary and secondary mode shapes that were drastically different. Such as one where the barrel moves up and down, and another where the barrel moves left and right.

Removing symmetry could cause the first few mode shapes to be very similar to each other with regard to where the end of the muzzle is pointing compared to the undeformed axis of the barrel. For example, even though this is a study of instability and not vibration, stand a ruler on end, push straight down, it will buckle and bow to one direction or the opposite. THe difference in these 2 mode shapes is drastic, yet they are mathmatically close and you have no control over which direction it wants to bow. Now, hold your finger in the midspan of the ruler, preventing lateral deflection in that direction, you force the mode shape of the buckle. The next higher order mode shape is an S curve with the midspan not moving, but these 2 shapes are mathmatically very different.

Anyway, my mind must be idle for me to dive into this!!

Baja Bill: I appreciate your input, and understand (I think!) what you are saying...I guess I should just say what I've tried over the years...I used to bed so barrel would be free floating..the typical recommendation. Then I heard somewhere, full bedding of barrel channel is better.
So I then carefully took my tests...all else being equal if I full length bedded in the same rifle I got improvements.
So, its a pragmatic approach...does it work? Yes. Why? I
don't know. But consider..if you have a very precise bedding throughout the entire rifle..that's usually considered optimum...meaning in a wood stock. So, what if you improve the precision of the bedding by glassing it in to a formed 'plastic' with nary any tolerance variation?
Isn't that by syllogism, even better...? Like one poster replied, "works for me"...and basically, I wanted to get
some input on this topic...other opinions...it sure is easier for me to bed & free float the barrel! Thanks for your input...you have a good point to make. Tom

The one time I tried a fully bedded Bolt action rifle was with a BRNO 600 30/06 I had. For whatever reason, I decided to bed this full length in glass. It came out nice and when I shot 5 shots from a cold barrel it shot very well (sub moa) If I kept on shooting, it still shot well. If however, I let the rifle cool down halfway (like the time it took to walk up and change the 100 yd target) the first shot would hit about 4 inches high. The next three would walk down to the original point of impact and the rifle would then group well again. If it was allowed to cool completely (say a half hour or so)it would group at the proper point of impact and shoot round groups. So under normal hunting conditions it probably would have worked well enough and this quirk would have caused no problem. I consider any accuracy quirk to be unacceptable though, so I floated it and enjoyed the improved consistency.
As I said before, I would love to see all my competitors at the range full length bed their rifles. It would give me the sort of edge I need to win!Regards, Bill.

look at these movies

http://www.varmintal.com/amode.htm

he isnt addressing bedding, but they are interesting, at least to structure geeks like me. Also, I question how much support a wood or plastic stock is going to provide to a steel bar. I think the fact that many styles have been successfully incorporated lends me to believe there is little benefit of one or the other, should one fail in a particular rifle, it may just be by chance.

Also, dont let me lead you to believe I have alot of experience with bedding rifles.