Click Here to receive an email update each time JMTPublishing.com publishes a new article.

Article Title: BENCH TOPICS: A NON-PERMANENT BEDDING TECHNIQUE (A 60 YEAR OLD IDEA AND PRACTICE PROVES ITS VALIDITY IN 2011)

Date Published: 03.07.2011

Author: Mark Trope

Author Email Address: txwordsmith@swbell.net

 

Figure 1.  Remington 513-T, rubber pad bedding has been installed.

 

What has been is what will be, and what has been done is what will be done, and there is nothing new under the sun. The Holy Bible, (English Standard Version), The Book of Ecclesiastes 1:9

 

These words ring true in almost every endeavor.  Ideas that some think are brand new, have usually been practiced, or at least conceived before.  This is also very true in the field of firearms. 

 

Recently, a simple device to enhance rifle accuracy has been placed on the market.  It looks a rubber donut with a couple of ridges on it!  The idea being, one places this device around the barrel, and vibration will be absorbed by the rubber donut.  Reduced barrel vibration is supposed to shrink the size of groups on a target.  

 

Of course the ring device requires no skills or tools to install.  The arm will not be modified, nor does it require any disassembly of the rifle to install.  The cost is of the ring is minimal.  So, even if it does little or nothing to enhance accuracy, there is nothing to loose (except a few dollars), and, who knows?  It may really work!   

Here’s the rub: this device is not new!  I recall an almost identical item being marketed & used in the 1970’s!   Some fellows said it helped, others saw little improvement.                                                                                                 

 

Even the stiffest barrel vibrates when a round is fired.  High-speed cameras have recorded the up & down, and left to right motions.  It’s astounding!  Now, recall we said some fellows saw an improvement in accuracy, while others saw little improvement?   The rubber ring concept, while sound, does tiptoe around a few important points.

 

Everything has a frequency.  Everything vibrates.  If a barrel isn’t concentric with the action, then the barrel will not vibrate in a repeatable pattern.  Then the bullet will not always exit the barrel when the muzzle is at the same point as the last round, hence, an enlarged group.  The same thing happens when the bore isn’t dead center in the barrel (it happens more then you want to know).   Often, a rifle isn’t properly bedded, the stock may have a crack, or the action screws are loose.  Any of those conditions will cause the action to shift within a stock.  If the action isn’t secure, or its mating surface with the stock fails to closely match, the vibration pattern simply won’t be repeatable!

 

Quite often, a fellow changes brands of ammunition, and even with the same bullet weight, the group is higher or lower on the target.  The usual accepted answer for this is a change in velocity.  However, the change in vibration will also cause group impact to change places!  

 

Ok, so this article is a test of the rubber donut ring, right?  Nope!  However, the use of rubber, vibration and making everything as consistent as possible are the themes of this article.

 

A discussion on a certain gun forum surrounded the different ways to bed a rifle.  Today, there are 2 accepted methods.  One is to epoxy bed the action and first inch or so of the barrel channel in the stock.   Epoxy bedding compound will produce a mirror image of the action.   Epoxy first came into use about the mid-1950s.   The epoxies of those days left much to be desired.  They were thin, and ran everywhere during application.  They were not impervious to gun oils or solvents, and often softened.  Some shrank after completely drying. But, as with most things, the compounds and resins steadily improved.                                                                                  

 

Today, we have epoxy gels that have the consistency of peanut butter.  They are much easier to use, maintain their size, and seem to resist oil and solvents well.  On the other hand, they smell awful until completely dry.  If one forgets to use release agent, the gun and stock are permanently joined!  Excess compound will have to cleaned-up immediately, or it will have to be sanded from the stock.  Usually, a novice will learn after doing 1 or 2 such jobs ways to work smarter and not harder! 

 

The second method is the pillar bedding system.  Pillars are epoxied into the stock at strategic locations.  They keep the action very slightly above the stock. Pillar bedding works quite well.  Of course one needs the correct size pillars (length, diameter and center hole size).  The stock must be drilled out to accommodate the pillars, and they must be correctly positioned to be effective. 

 

Then, during the discussion, a fellow brought up the rubber-pad bedding system used so successfully on the Winchester 52C during the 1950’s. That comment jogged my memory!   I ran to my library and looked in a book that mentioned this rubber-pad bedding system.  The Winchester 52C had 3 thin, rubber, rectangular pads the action rested on in the walnut stock. 

 

The pads served several purposes.  They absorbed vibration. Even though the pads were thin, they had a bit of give.  It was not a hard surface to hard surface contact as happens between steel and wood.  Consider your automobile or truck.  The engine & transmission mounts are steel plates with vulcanized rubber in between. They absorb vibration.  The pads in the Winchester 52C conformed to the exact shape of the action.  Even stampings or numbers in the bottom of the action will have a mirror image impressed into the pad.  The pads in the 52C acted as a type pf pillar.  They kept the action ever so slightly above the stock.

 

This discussion got me to thinking about a rifle I own.  I have a Remington 513-T that shoots fairly well for a rifle of its type, but I always felt it should group somewhat better then it did.  When I got the 513-T, it had an issue with misfires.  For the full story of the Remington 5-Teen series rifles, and fixing the misfire issue, see this article:

 

http://www.jmtpublishing.com/articles/2011/Those_Amazing_Teen_Years.asp

 

The shim inserted into the bolt corrected the headspace issue.  Rounds were now 100% sure-fire, and a slight increase in accuracy also resulted. The accuracy increase was due to all rounds now having complete ignition.  But, as I said before, I still felt the rifle should do better.                                                         

 

Figure 2.  Unertl barrel-mounted scope, some of these type scopes can weight up to 44oz!

 

 

 

 

Figure 3.  Unertl barrel-mounted scope on a Winchester 52C.

 

Figure 4.  My Remington 513-T (1964 production) has dovetail grooves for an action-mounted scope, as well as D&T’ed holes for barrel blocks.

 

The 5-Teen series rifles only have one screw to secure the action to the walnut stock.  The 513-T has a long, (27“) thick, bull barrel.   My rifle was made in 1964, so its receiver is grooved for an action-mounted scope.  But, the barrel is also D&T’ed to accept blocks to mount a long, target-type scope (Note.1).  Remington didn’t even begin to groove receivers until the mid 1950’s.  Prior to that one had to use a barrel-mounted scope (Note.2).  Some of those scopes can add up to 44 oz to the barrel (Note.3).  As one can see, an awful lot is being asked of that one, single screw!! 

 

Having less then 2 screws to secure the barreled action to the stock introduces the chance for bedding problems to arise.  I decided to pull the barreled action out of the wood to see what the bedding area of the stock looked like.  Usually, unless there is 100% contact, then areas of movement will show up in the wood as either shiny spots, or black spots. 

 

Figure 5.  Remington 513-T only has one action retaining screw.  Note uneven shiny spot around screw hole.

 

 

Figure 6.  Remington 513-T action is not bearing evenly in the rear area.  Note dark line to the right of the trigger slot.

 

Sure enough, the evidence was in front of me the moment the inletted area of the stock was exposed.  A shiny area where the action-retaining bolt goes through.   There was a black area at the back of the action where the action was shifting ever so slightly.  That shift would cause the muzzle to be at slightly different places as bullets exited the barrel. 

 

The design of the inletting in a stock for a 5-teen is not conducive to pillar bedding.   I could have easily epoxy bedded the action into the stock.  However, I kept thinking about the rubber pads first used 60 years ago in the Winchester 52C”s.  The accuracy of those rifles was, and still is the stuff shooting legends are made of! 

 

Figure 7.  The rubber insulator ring from a bicycle wheel will serve as our bedding pad material.

 

I wondered if I could make rubber-bedding pads, and install them between the action and stock of the 513-T.  Of course the first order of business was finding suitable material to make the pads.   After a bit of consideration, I thought the rubber insulator ring or inner tubes from bicycle wheels or bicycle inner tube material might work.  A local bicycle shop bequeathed me examples of both.  They discard used ones every day.  The insulator ring is like a large, wide, flat rubber band that goes around the rim to protect the inner tube.  The insulator ring seemed to hold the most promise for this project.                                                                                                         

 

Because I would be drawing lines on the insulator ring with a pen, I washed it well in hot, soapy water to remove any dirt or dust that was on it.   

 

Figure 8.  Measuring the length of the inletting.

 

The next step was to remove the barreled action from the stock.  Now I could take careful measurements with a tape measure and transfer those measurements to the piece of insulator ring that would become my bedding pads. 

 

Figure 9.  This piece of material is all we need to make the bedding pads.

Figure 10.  Full length of pad before cutting & trimming.

 

Figure 11.  A fired .22 case makes hole for action screw.

Figure 12.  Lines are laid out on pad for trimming.

 

Figure 13.  Front pad installed in stock.

Figure 14.  Rear pad cut and trimmed to size.

 

Figure 15.  Rear pad installed in stock.

 

Figure 16.  Front & rear pads installed in stock.

 

I simply cut and trimmed the pads to shape and size.  I found a fired (I did say fired right?) .22 case made a perfect punch to make the hole for the action screw in the pad.   After the pads were placed in the stock, the barreled action was carefully inserted, and the action retaining screw tightened.   Now all that remained was to see if this worked.  That means range time!  Bullya!

 

Figure 17.  Set up at the range.

 

As usual for this time of year, the wind was running hard at the range I shoot at.  But I felt I should be able to tell if this project met the goal of improved grouping.

 

Figure 18.  A typical 5-shot, 50-yard group prior to pad installation.

 

Figure 19.  Another 5-shot, 50-yard group prior to pad installation.

 

 

Figure 20.  A 5-shot, 50-yard group after bedding pad installation.

 

 

 

 Figure 21.  Another 5-shot, 50-yard group after bedding pad installation. The wind got me on that last shot!

 

It worked!  Seems there really is nothing new under the sun!  A return to 1950’s technology proved it’s still as valid in 2011 as it was 60 years ago.  If you have a rifle that seems a bit dodgy about grouping, and you’ve exhausted all other possibilities, consider this simple, inexpensive technique.  Hey, you never know! 

 

ARTICLE NOTES FOR: BENCH TOPICS: A NON-PERMANENT BEDDING TECHNIQUE (A 60 YEAR OLD IDEA AND PRACTICE PROVES ITS VALIDITY IN 2011)

NOTE.1

 

Remington began to groove receivers for action-mounted scopes in the mid 1950’s.  Prior to that one I had to use a barrel-mounted scope.  However, Remington continued to D&T (drill & tap) the barrels for the blocks to mount a long, target-type scope during the entire run of these rifles, which ended in 1969. It wasn’t until the early 70’s that action-mounted scopes of true match quality came available.

 

NOTE.2

 

The Remington 513-T was not only set up to take scopes 2 ways, it was factory supplied with a precision micrometer rear peep sight (a Redfield 75), The Redfield 75 was on a quick-detachable thumbscrew, so one could switch from iron sights to scope quickly.                                            

 

A Redfield globe front sight is dovetailed on the front of the barrel.  A set of different post and globe inserts was supplied for the globe sight.

 

NOTE.3

 

All of the long, target-type scopes are now out of production.  They are some of the best optics ever produced.  They carry hefty prices on auction sites.

 

 

Copyright and Disclaimer Info