Glass bed your bolt action for super accuracy ?

With a decent but not perfect stock to action fit, accuracy acceptable to most people is what most new factory produced rifles come with out of the box. For the manufacturers, the cost of producing rifles with a perfect fit between the action and the rifle can’t be justified by the current market or price they can charge and still sell rifles.

Although all of the top rifle manufacturers understand that quality is the key to selling rifles, the question of “how much quality to sell rifles”. That old balance of cost vs revenue is the driver of our free enterprise an after all, there is no rifle producing company out there that is not in business to make as much profit as possible.

The level of accuracy produced seems to be quite acceptable to the general shooting population as thousands of new rifles are sold each day in the US. Then there are the demanding shooters who must have precision at the highest level but don’t want to mortgage the house to acquire all of the rifles we need……or want.

For these reasons, it is necessary for shooting enthusiasts…like us….to do a little extra to a factory produced rifle if superior accuracy is the goal. Glass bedding the action to insure that perfect fit, and no movement during the shot or from shot to shot, is in my opinion, the first step.

Most every factory made bolt action rifle’s accuracy can benefit from having the stock bedded to perfectly match the action to eliminate movement during the firing process.

What is glass bedding ?

Any movement of the action during recoil or the firing process robs accuracy or consistency of hot placement. The goal is to have perfect match between the action and the are of the stock it sits in to eliminate movement.

Glass bedding compound is poured into the traditional rifle stock with barreled action removed to form a perfect match between the stock and action.

Normally a stock, whether wooden or polymer is deepened enough to accept the bedding compound. Then the action is reinserted and kept firmly in position until the compound is dried. Modeling clay and other materials are used to ensure bedding compound doesn’t get into undesired places. Once dryed, this new mold prevents movement of the stock and barreled action in relation to each other.

The picture above shows a very good and clean glass bedding job on a wooden stock. The black material you see is glass bedding which doesn’t swell or contract with changes in humidity. This new glass bed will ensure very little if any change in position of the action over time.

Why glass bed a stock?

If the action is able to move around in the stock during the firing process, even a tiny little fraction of an inch, you are not getting, and never will get, the most consistent performance from that rifle. After all consistency from shot to shot and day to day is the ultimate definition of accuracy.

Glass bedding your stock to hold the action perfectly still is like putting your rifle into a vice to shoot it. If you have ever had a rifle that shoots consistently for a few shots and then the zero seems to change, or a rifle that sprays bullets around the target in a shotgun pattern, a moving action or loose fit to the stock could be the cause.

This s not to say that glass bedding will solve all problems with consistency but it is the best place to start.

What is the difference in glass bedding and pillar bedding

Pillar bedding is just the insertion of metal cylinders that fix the distance between the action and stock into the glass bedding compound before it dries. These pillars are just compliments of the bedding job. Here are a few types from Amazon but if you decide to use these make sure they work with your rifle and stock.

Some rifles come with metal pillars already designed into the stock. An example is the Remington 700. See the bar in front of the action screw in the photo below.

Glass bedding around these pillars is an excellent way to prevent movement in any direction. As mentioned earlier, a pillar is an enhancement to glass bedding.

The more irregularities that are designed into the action the more point the action has to lock to to prevent movement.

How to glass bed your stock

The object of the process is to give the action a place to rest with a perfect fit which doesn’t allow it to move, even when under recoil. It is not necessary to bed the entire action. All you really need to do is bed areas that will allow the stock to lock to the action better with the appropriate torque on action screws.

Here is the bedding compound I found to work best. It is specifically made for bedding rifles but can be used on other projects.

If you have a pillar designed into your action or any kind of indention or protrusion on your action (see the photo above), this is always a good place to bed but don’t bed any further past the action on the barrel than about 3/4 of an inch. You want the action locked solid to the stock, but the barrel should be free to do it’s normal whipping action or harmonics in order to preserve accuracy. A good bedding job may require removal of a small amount of stock material to allow enough bedding compound to be put into the desired area.

This is easily accomplished with a small wood chisel. Leave the area where wood is removed slightly rough enough to allow the bedding material to have a surface it can really bond to.

A rough surface is better than a smooth one. Just don’t leave any loose wood or polymer in the area. Too much of this will allow the dried compound to come out.

Use modeling clay to build a dam if necessary to contain the liquified bedding compound so it doesn’t get to threaded, trigger areas, or anywhere else it doesn’t need to be. Also, use a liberal amount of a release agent.
Don’t glass bed any area on the stock that won’t allow the stock to be picked straight up once the compound is dried. Even the smallest hook or “L” shaped angle can prevent removal of the action in the future.

Once you have the bedding compound in the right areas and only enough that it won’t ooze out over the sides when then action is placed back into the stock, apply a liberal amount of release agent to ensure easy removal once the compound hardens.

Insert the barreled action back into the stock. Replace and torque your action screws….semi tight but not completely. Clean up any ooze immediately. Once this stuff hardens it is there pretty much forever. Leave the rifle like this for 24 hours or until you are sure the bedding compound is dry and begun to cure.

If you are not comfortable doing this yourself, or are not competent with your hands and tools, I would suggest paying a gunsmith to do the work. Especially if this is your first time to glass bed a rifle, the job will be cleaner and more functional letting a pro handle it.

How much does a glass bedding job cost?

If you do it yourself and use the components recomended above, it will cost around $20 max.

A gunsmith will do this process for you and the price is usually very low. I had a Remington 700 pillar bedded only for around $50. This cost was worth it to me not to have to clean up the mess that results when you do it yourself.

Gunsmith prices will vary by rifle and the amount of bedding prep work that is needed. If you really want to do this yourself you can. There are many videos on youtube showing and explaining the process. The best one I have seen was posted by Cavedweller where he accomplished outstanding results with a Savage A17 project. It shows how easy it is to do and how much accuracy improvement you can get with a good bedding job. Check it out below.

What improvements in performance will I see?

Most polymer stocks with a great fit already between the action and the stock may not benefit a great deal from glass bedding. On all stocks the more contact you have with the action the better. You want to see contact out to about 3/4 inches on the barrel after the action. From that point forward the barrel should be free floated away from the stock.

I bedded a Remington 700 in .2506 caliber. My group size went from slightly over one inch at 100 to 1/2 to 3/4 of an inch consistently. This rifle is in one of the older wooden Remington stocks.

The image above is not my exact image but the improvement was very similar. This image came from Hill Country Rifles I recently glass bedded the Savage FVSR 93R17 you see below and yes I did it myself and it turned out pretty well. This rifle was already shooting sub MOA. I didn’t see a great deal of improvement by doing the bedding but there really wasn’t a lot of room for improvement.

It was already in a polymer stock with Savages plastic stock lug along with the anchor posts from the action firmly attaching the action to the stock with not a lot of movement. I will say that the stock on the FVSR below leaves a lot to be desired from the factory. In the fore grip area it is was very flimsy.

While doing the bedding job I also added more bedding compound inside this area. This seemed to have the most impact by minimizing flex when on a bipod. For more information on how to stiffen a polymer rifle stock, click here.

With any bedding job, you should expect tighter groups which goes without saying. In addition, you should see less change in zero from range trip to range trip. Especially if you bedded a wood stock. I know there are arguments for laminated woodstocks and how they resist change due to elements, but I have polymer stocks on all guns that I shoot routinely.

Is bedding the only option?

No, if you know you won’t be satisfied with the stock you have, even after bedding, there are many types of after market stocks and chassis available. Most after market stocks and chassis come with an engineered solution to insure the best contact and fit between stock and action. This eliminates the need for bedding.

This means you just bolt up your rifle to the specified torques and go shooting. There are endless choices out there from a couple hundred dollars to thousands of dollars. This choice isn’t right for everyone on their rimfire rifles. I don’t like spending more money on a stock than I have in my entire rifle and optic, but if you have the money and don’t mind paying more for per square inch of accuracy gained, have at it.

What else improves accuracy?

For more ideas on improving the accuracy of your rimfire, check out the articles below.

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Conclusion

Anchoring actions into stocks through the process of glass bedding has been a practice used to improve accuracy for years. It is still the one of the necessary tasks to bring the accuracy out of traditional bolt action rifles with wooden stocks. Don’t hesitate to use this tool. It can never make accuracy worse, only better.

Resources Hill Country Rifles