SMK XS 501 Co2 Air Rifle IMPORTANT Additional INFORMATION by Terry.
The 501 is not a toy and can cause serious injury or death if handled incorrectly.
This is a single shot bolt-action rifle powered by one or two 12-gram Co2 bottles. If you only want to shoot a few pellets then you can use one Co2 bottle rather than two. Just put a used one in first. The first gas bottle goes in nose first and the rounded back facing forward, and the second one goes in with the rounded end in so the capsules are back to back.
Tightening the front cap will pierce the front capsule while the firing of the gun will pierce the first capsule you put in. Make sure that the front screw under the round cap is unscrewed or it may leak at the front. This screw is to release any residual pressure that may be left in the reservoir. Make sure there is no pressure left in the reservoir before you attempt to unscrew the front cap, or it will fly out of your hands. I have supplied quite a few of these to air gunners who have done this.
Make sure the gun is not loaded before you handle it, and there is nothing in the barrel.
Shooters and spectators should wear protective goggles.
Never let the gun point at anyone or anything else you don’t want to shoot.
Hold the air rifle in one hand, then pull the bolt back smartly to cock the gun which should make a click when the sear is engaged. They have an automatic safety but make sure that the safety is on. The safety shows an S when the gun is safe (but never trust them) and it shows a F for Fire. With the bolt is at the back you can put a pellet in the groove facing forward. The flared skirt is at the back. It helps to point the gun downward to help the pellet drop into the barrel. Placing a pellet in the breech while holding the gun Horizontally and pushing the bolt forward is not as accurate as the pellet drags across the bottom of the channel. This can cause a slight damage to the underside that can reduce the accuracy. Guns that have a magazine can have similar problems.
When you are on target then push the safety off and the gun is ready to fire. If you take the safety off but decide not to shoot then you can put the safety on again by pushing until it shows the S.
When the gas is low and you want to put new bottles in then fire the gun empty until there is no pressure left, as only a little pressure will force the front cap out of your hands and you may damage something or lose it. There is a small screw at the front under the front domed plastic cap. This can be screwed in which will push the valve open to release the gas.
The power of the standard gun in .22 is around 9.5 ft lbs to 10.5 ft lbs. My tuning kit will bring them closer to the legal limit. They don't normally have trouble getting close to the legal limit of 12 ft lbs in .22 calibre.
The .177 version will be about 8 to 9.5 as they are not as efficient.
The gun is capable of being bulk filled with Co2. If you use the bulk fill method then make sure that the liquid is going into the gun rather than just the gas, which is at the top of a cylinder. Co2 is in liquid form in the bottle so it will depend on the bottle as to whether you have to hold it upside down or upright to fill. Some bottles have a syphon tube that goes down to the bottom of the bottle to pick up the liquid while others may not have that. If yours does not have the siphon tube then it would have to be Held upside down to fill the gun with the liquid.
To change the release valve seal then it is easier with a simple tool, I have put a photo below. I have put them on this site so it is easier to fit the seal on the brass carrier.