Whenever I look at a new rifle the stock is one of the main features I hone in on. It doesn’t matter how powerful or the inherently accurate, if the stock is not right I’ll never wring the full potential from the gun. I’ll hold the rifle and look at it while getting the feel, place my face against the comb to get an idea of how the gun will hold when I have a scope mounted, I’ll grip the pistol grip to see if it fits comfortably and cradle it in my arms to see how it will carry. The basic elements of stock design relate to what material(s) the stock is fabricated from and how the individual components are formed. Almost all airgun stocks are made from wood or a synthetic polymer material, though some designs do incorporate portions of the action metal work or reservoir tank into the stock. The primary design objective is to provide enough flexibility that it can be shaped or modified to fit a range of shooters, which makes wood an obvious choice; it is relatively simple for a skilled craftsman or a machine to shape or reshape, it is very durable, the grain and patterns are often works of art unto themselves, it¹s warm and easy to grip, and the expense can range from minimal to very expensive depending on the shooters requirements. Very attractive raw material is available from many sources, and most would argue that wood and blue steel are a natural match for one another.
Composites made of fiberglass and other synthetic materials yield some advantages over traditional wood furniture. They offer far greater strength and structural stability than natural wood, and therefore can be more easily shaped with ergonomics dictating design. There are other advantages; synthetics are harder wearing and they do not absorb moisture. I used to say that on the downside the aesthetics are less appealing, but some guns such as the FX Monsoon are downright pretty, and the superb handeling of the Verminator made me drop this bias. Synthetics are difficult to modify and while these stocks are more rugged, if you do happen to damage on they can be difficult to repair.
Laminated stocks are made using several layers of laminated wood that are impregnated under pressure with chemically-cured resins. These stocks offer a compromise between the aesthetics of wood and the structural stability of the composites. And if different types or colors of laminates are used, very interesting and beautiful patterns can be obtained. But because of the resins used to bond the layers, these stocks tend to be very heavy and are therefore not my choice in a hunting rifle. I’ve got a laminated stock that Michael Chavka made for my Marauder, which is both a work of art and replaced the very blocky standard stock ….. but I don’t like carrying in the field because it is heavy….. plus I don’t want to scratch or ding it. Like I said, it is a work of art!
The shape of the stock is dictated by the type of gun, how it will be used, and the individual shooters preferences. There are many types to choose from; Sporters, thumbhole, bullpups, takedown, to name a few… however the primary requirement is that it fits the shooter. I like a stock that is light weight with a longish pull, a cheek piece that lifts my line of sight to allow consistent mount of the rifle with the selected optics, a fairly thin wrist and a rounded forearm. It does of course depend on the type of gun I am shooting; the stock of a spring-piston air rifle is limited in many ways by its function. When compared with a pre-charged pneumatic rifle stock, the stock on a spring piston rifle tends to be less well shaped and far less elegant as it must be engineered to manage the stress placed upon it as a part of the cocking process. But when all things are considered, the air rifle stock must be comfortable to mount if one hopes to achieve consistent accuracy, and it must be light enough to carry in the field. The forearm of an air rifle stock must be wide enough to accept the air chamber. Because of this functional requirement, the stocks of most airguns tend to be quite bulky. There are a couple guns now on the market which use the air reservoir as the forestock; such as the Daystate Wolverine Type B and the FX Royale, which are both aesthetically and ergonomically great examples of function and form in alignment!
The buttstock is the part of the stock which comes into direct contact with the shooters shoulder and the comb is the part of the buttstock that comes into contact with your face. The comb sits atop of the buttstock and has three primary configurations; raised, dropped or straight. The shape of the comb depends on what type of sighting system intended to be used on the rifle. If your rifle has open sights that are mounted on the front of the receiver where the barrel breaks, the comb will be dropped. This means that the top line of the comb falls away from the front to the rear. This allows the cheek to be placed against the comb and your eye will be in line with the open sights. If the rifle has a raised comb it was designed for use with a scope. A raised comb places the top edge of the comb moderately above the top of the receiver and places your line of sight more directly in line with the centre of the scope or sighting aperture. A cheekpiece helps improve shooter comfort. Generally speaking, the more generous the shape the more comfortable the rifle is to shoot. Cheekpieces on target and field target guns are sometimes completely detached from the buttstock and incorporate a built-in adjustment mechanism that allows the comb height to be adjusted to fit the individual shooter. However, on a hunting rifle I feel this is too much hardware adding additional complexity and weight to the stock. The shape of a buttstock really depends on the degree of pitch or angle of the buttplate. Most air rifles have negative pitch which means that the buttplate angles forward at the bottom of the buttplate and rearward at the heel of the buttplate. As you increase the amount of negative pitch the rifle feels as more muzzle heavy. Decrease the amount of pitch and the rifle feels heavier in the buttstock. Pitch angle helps to balance the rifle and makes it easier to hold steady.
The length of pull or LOP is measured from the forward face of the trigger to the end of the butt plate or butt pad. It should be measured to the point halfway between the heel (top) and the toe (bottom) of the butt plate. LOP is an important measurement on the stock because the length of the buttstock will greatly affect how well you can hold your rifle and how well you will shoot. If the LOP is too short you will pull your shots to the right. If the LOP is too long the rifle will tend to ride upward and outward during recoil which will usually make you shoot low and to the left (the opposite applies if you are a left-hand shooter). For the air gun shooter, correct LOP can be determined by placing the buttstock along your forearm. Slip your trigger finger onto the trigger and the rest of your fingers around the pistol grip or wrist just like you would do if you were shouldering the rifle. Look down and see if the face of the butt plate or butt pad rests against your biceps. If it touches the surface of your biceps then the LOP is very close to being correct. The amount of drop a stock has allows your head to fit the stock correctly. A stock needs some amount of angled drop along the top of the comb to allow the shooter to place his shooting eye directly in line with the scope. Since a scope will usually sit higher on top of the receiver than a set of open sights, the stock for scope sighted rifles should have less drop than a stock for a rifle equipped with open sights. The drop consists of two different measurements; drop at comb and at the heel. However you can get a good idea of the required drop by placing a straight edge on top of the receiver and making the measurements. This is the simple way to do it but you need to take into account how far the sights or scope will sit above this line so you can make the necessary changes in comb height to allow for correct head placement. Open sights typically require about a half inch drop at comb to be effective. Most scopes require about an inch and a half to two inches of drop to fit correctly. You can adjust the amount of drop with adjustable pads and slip on sleeves that permit you to change the comb height without making any permanent alterations to your stock.
One of the trends I see in stock design, along with the growing number of synthetic stocked guns, is the inclusion of adjustable furniture. I was shooting a couple of value priced guns over the weekend, the Hatsan BT65 and the Marauder Synthetic, and they both had adjustable stocks. There was a lot more latitude with the Hatsan which allowed the cheekpiece height, the length of pull, and the shoulder pad to each be fine-tuned for the shooters body habitus and preference.
I was in Japan on business last month which slowed my shooting down a bit, but this month I’ve got a 4-5 day block off and trying to decide where to hunt. Thinking about Arizona, Kansas, or S. Dakota for prairie dogs …… maybe Central Cali for some ground squirrels, we’ll see what cheap tickets I can find! We’re getting close to the opening of American Airgunner, I’ll post a link in case you don’t get Pursuit Channel or Sportsman Channel in a week or two.
Have fun shooting this summer, post a message and let’s see what success you’ve had on your warm weather varmint shoots!