How to stiffen a plastic rifle stock

On some of the OEM polymer stocks coming from manufacturers today, it doesn’t take long to figure out that flimsiness, or lack of stability in this area, quickly robs accuracy gains achieved through other rifle improvements.

Why would well known and respected rifle manufacturers sell their products with this type of stock? For the same reason car companies sell 4 wheel drive trucks with smaller street tires designed for the street instead of off road.

It allows them to keep the initial price competitive, they meet the needs of the majority of the market, and selling larger more aggressive tires to the buyer later creates an opportunity for an upsell after the initial sale of the truck.

Most serious shooters will just quickly change out a flimsy stock with an aftermarket variety like the Magpul X22. Doing so is almost like getting a good action glass bedding job while stiffening the stock and installing an adjustable cheek riser.

If you are like me and enjoy making what you have work at a low cost, you can strengthen your OEM stock, do your own glass bedding at the same time, and just install an aftermarket cheek riser. You can do this for about half the cost of a new aftermarket stock and in the end have a very workable set up.

What issues are caused by a flimsy stock?

Just the weight of the rifle sitting on a bipod or shooting bag can cause flex in different areas of the stock which will affect the harmonics and position of the barrel when aiming. This flex can occur anywhere in the stock where the polymer is not thick enough to overcome it but the fore end is usually where the maximum flex will be found and is the area where most of the shot error occurs..

With a really flimsy stock the flex can change from shot to shot depending on how consistent you basic shooting fundamentals are applied. In other words, a flimsy stock adds variability to the shooting process. To become proficient at long range or precision shooting, our job is to remove as much variability as possible.

A strong rigid stock will prevent errors that you may never know are happening. A flimsy stock could be the reason that one rifle you have won’t group as consistently as it should.

How to stiffen a polymer stock

You must determine where your stock needs to be stiffened that will yield the most stability. Typically this is the fore end but you can also remove the butt plate and put material there, or drill a hole into the pistol grip and fill that area as well.

Below is a picture of an OEM Savage stock where bedding compound has been used to fill some of the voids in the stock underneath the barrel. Once this stuff hardens it is rock hard and completely eliminates the ability to twist and flex the fore end of the stock if enough of the material can be applied. It also adds a small amount of weight to the front of the rifle which is always good with a long range rifle.

When doing this make sure you don’t let the bedding compound come in contact with the sling mounting screw or any other threaded items before they are completely coated with a good release agent well before the bedding compound is applied.

Before applying the release agent, liberal use of a good contractor’s grade masking tape will make the job cleaner and insure the bedding compound only goes where you want it. Also, only put enough bedding compound into the stock to accomplish stiffening but keeping the barrel free floated and not touching the stock or bedding compound in any place.

I have seen some glass bed both the action and the entire barrel. I have no idea why someone would do this as it completely destroys barrel harmonics in my opinion. The barrel should be free floated. While doing this you may as well go ahead and glass bed your action to prevent any movement within the stock and help optimize accuracy.

I have seen some glass bed both the action and the entire barrel. I have no idea why someone would do this as it completely destroys barrel harmonics in my opinion. The barrel should be free floated. While doing this you may as well go ahead and glass bed your action to prevent any movement within the stock and help optimize accuracy.

I recommend bedding the action and about an inch or so of the barrel. You may have to build a small dam with modeling clay to keep the material out of the trigger area, or any other are where bedding compound should be. See this article for more information on glass bedding

How can you tell if improvement was made to stiffness

The best way to determine if your work yielded any improvement is to shoot it at 50 yards. You should see groups that are tighter than what you had before the project.

There is no way to say how much tighter they should be because that all depends on how flimsy your stock was to begin with, but there should be at least a small amount of improvement. Remember, a small amount of improvement at 50 yards means more improvement at 200 and 300 yards.

Good luck and happy shooting.