Broke my Crosman 1077

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JohnKSa

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I was going to try shooting the scaled AQT target I cooked up, but using a repeater to see if I could make the time limits. I only have one repeating airrifle and it's a Crosman 1077. It's not really my favorite air rifle but I got a good deal on it many years ago. I have hardly shot it since. Although it is a 12 shot repeater that can be fired simply by repeatedly pulling the trigger, the trigger isn't great and that makes shooting it less fun than it might sound.

I uncased the rifle and found that the CO2 cartridge was stuck in place. I didn't have it actually charged, but I had left it with a full cartridge in the gun so it could be charged by tightening down the screw.

In the process of messing around with the gun, I followed the procedure for unjamming a pellet and both tabs broke off the plastic barrel latch. So instead of shooting it, I took it apart. Learned some stuff that might be handy.

For reference.
https://support.crosman.com/hc/en-us/article_attachments/201669754/C1077-OM2.pdf

This worked for me and for the particular 1077 I have, but I have no idea of your mechanical aptitude nor of what specific variant of 1077 you have. So I can't guarantee it will work for you and your gun.

Removing a stuck CO2 cartridge.
  • Remove the three stock screws and lift the action out of the stock. There's a port on the underside of the tube that holds the CO2 cartridge and you can poke the cartridge out easily.

Replacing the barrel latch.
  • With the stock removed, place the action on its right side and remove the small screw at the front of the action that holds the plastic receiver to the barrel housing.
  • Turn the action on its left side.
  • Get a piece of soft wire (I used a pipe cleaner but a wire tie or something similar would work too) and loop it around the trigger and the trigger guard so that the trigger is held to the left and can't move to the right. This will keep the trigger assembly in place while you do the replacement--if you're careful and don't bang the gun around. You're not trying to secure the trigger against huge forces so don't go nuts with the wire. You just want to keep it from moving to the right. Don't pull it back and wire it in the "fired" position--I don't know what that would do because I didn't try it.
  • Remove the screws that hold the plastic receiver together as well as the small screw at the front of the action that holds the receiver to the barrel housing.
  • Gently lift the right half of the receiver upward away from the left half. Push down on the safety while lifting up on the receiver to keep the safety from pulling upward and to make it easier to separate the two halves. The wire should hold the trigger mechanism in place as long as you're careful.
  • With the right half of the receiver removed, you can carefully lift the barrel housing/CO2 tube/valve assembly up and away from the left half of the receiver. But before you do this, be careful to note how it all fits together.
  • The valve assembly fits snugly into the little space in front of the hammer. Pay attention to how it is oriented as you'll have to get it back exactly as it came out for everything to fit back together. Try not to disturb the hammer or the trigger mechanism. The valve assembly is held to the CO2 tube only with friction so don't wave it around. The brass tube joining the valve assembly to the CO2 tube is held in place on both ends only via friction from O-Rings at its insertion points. If it comes loose, you can simply push it back in--but you can keep it from coming loose if you are careful.
  • Pay attention to how the barrel latch/barrel fit into the receiver.
  • Pay attention to the barrel latch orientation. It can go on one of two ways but only one way will work. The "fin" on the bottom of the barrel latch is offset to the right side of the gun when installed properly and the ramped side of the "fin" goes forward.
  • The barrel latch will snap right off the barrel and the new barrel latch can be snapped into the groove on the barrel where the old one fit.
  • Making sure to get the barrel latch/barrel back where it goes and getting the valve assembly back into its little niche and properly oriented, reinstall the barrel/CO2/tube/valve assembly. Try not to disturb the hammer or the trigger mechanism. The wire should keep the trigger mechanism and hammer from coming out of the gun or moving out of position as long as you're careful.
  • Place the right half of the receiver back in place taking care to line up the safety in the process.
  • Replace the long screws holding the receiver together but don't tighten them. Leave them just a hair loose. Turn them backwards a little when first starting them to make sure you don't cross thread them into the plastic. They should turn easily when you have it right.
  • Install the small screw at the front of the receiver but leave it just a hair loose.
  • Turn the action over and install the small screw at the front of the receiver and you can tighten it down. Don't go nuts, it just needs to be snugly tight.
  • Turn the action back over and tighten down the small screw at the front of the receiver.
  • Tighten the long screws holding the receiver halves together but remember that they are only screwing into plastic. You can very easily strip them if you overtighten them.
  • Reinstall the stock and remove the wire on the trigger and you should be good to go.
 
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