One of the latest selling features for the air and CO2 pistols is the so-called COMPENSATOR If you want to be right on top of things, better rush right out and grab one. Before you do, however, better try to understand exactly what they do and don’t do because some do...and some don’t.

There are two distinct jobs that compensators are supposed to do. The first function is to stop the fast moving turbulent gasses that follow the pellet out of the muzzle from upsetting the pellet in flight. We know that the escaping gasses at the muzzle are traveling faster than the pellet in its first few inches of flight. These gasses overtake the pellet and tend to tip the very light skirt of the pellet. This, of course, can cause a wobble of the pellet in flight and result in inaccuracies. This principle is well known to high power rifle shooters who take great pains in getting exactly the correct crowning of the muzzle of their rifle. Accurate crowning tends to disburse the gasses mort uniformly. The lighter the bullet, the more pronounced it is. Because of the very slow speed and lightness of the match grade pellet tipping can be very pronounced. In this regard the “compensator” [a poor name for it] collects the fast moving gasses and diverts them away from the pellet.

The second job that the comp. Is supposed to do is to stop the upward muzzle jump of the pistol. This upward deflection of the muzzle is caused by recoil. By deflecting the gasses upward the comp. Is supposed to stop or reduce the muzzle jump. It COMPENSATES for the muzzle jump and theoretically the muzzle remains motionless during firing. The system of drilling holes in the barrel of a rapid-fire pistol has been used effectively for years to reduce muzzle jump. The number, size and placement of the holes behind the muzzle determines the amount of COMPENSATION. Some are even adjustable.

Lets look at some of the compensators that are on the market to-day; Figure “A” represents a standard barrel without any fittings. By adding the first type of comp. {figure “B”] the pellet passes through an open slot in the comp, and then passes through a close –fitting opening. The gas pressure building up behind the pellet cannot follow the pellet through the small opening and are directed upward through the slot in the comp body. This comp effectively satisfies our first situation by diverting the gasses away from the pellet but it does not properly satisfy our second problem. It diverts the gasses upward and stops some muzzle jump BUT ONLY AFTER THE PELLET HAS LEFT THE BARREL. The upward movement of the barrel caused by recoil starts to take place long before the pellet leaves the barrel. If the compensator is to have any effect on the barrel movement at all, it must control the barrel before the pellet exits, otherwise the damage to the pellet has already been done. This compensator will reduce barrel movement after the pellet leaves and so it may feel better to the shooter but remember it is not really doing the pellet any good. Another fault with this design is that it can still tip the pellet because the gasses are all escaping in one direction.

Compensator “C” does a very good job of deflecting the gasses outward in all directions equally. It has four ports around the barrel and gasses are deflected uniformly. It does not make any claims to stop muzzle jump. Muzzle jump is controlled by drilled holes in the barrel…the only way the job can be done. This way muzzle movement is dampened BEFORE the pellet exits. No No No…..don’t try to drill holes in your old barrel. It is technically impossible to drill holes without getting a burr on the inside of the bore. The factory drill these holes by laser…..a very expensive process and that’s why we don’t see many of the factories doing it. Pellet velocity is reduced by a few feet per second but accuracy is not compromised.

It is virtually impossible to test the actual effect that these new goodies have on your pistol. A pistol clamped in a vice will react much differently than one that is hand-held. Pardini say that they have tested compensators extensively and they can prove that they do no good, therefore they don’t make them. Walther’s system on the LPM1 was excellent but they abandoned it in their new models. The best and only drilled barrel system available right now is the Steyr LP10.