Disassembly of the Swiss K31 Rifle and Bolt
First off, get familiar with the parts of the bolt that you will be dealing with.
1. Cocking Piece - the tab on the left of the cocking piece is referred to as the Cocking Piece Sear.
2. Firing Pin Spring
3. Firing Pin
4. Locking Sleeve (the curved cut-out is referred to as the Cam Follower Pin Slot)
5. Attachment Lug
6. Cylinder
7. Extractor Groove
8. Extractor
9. Bolt Plug
10. Bolt Handle/ Cam Follower
Before dissassembly it is important to check for and remove all cartridges by inspecting the magazine and chamber.
Bolt Disassembly
1. Grasp the bolt in the left hand; place the cocking sear between the two slots on the bolt plug.
2. Remove the cam follower pin from the helical slot in the locking sleeve; them remove the cam follower by pushing forward through the slot in the bolt plug.
3. Grasp the locking lugs with the thumb and the middle finger.
4. Hold the cylinder with the index finger next to the extractor.
5. Separate the firing mechanism from the locking sleeve and cylinder.
6. Separate the cylinder from the locking sleeve.
7. Remove the 3mm extractor with a screwdriver by pushing it forward (Avoid removing the extractor if possible as removal make break or weaken the spring).**You will have to lift the edge of the extractor first so that it clears the bolt face**
8. Retain the firing pin spring by placing the cocking piece sear in the firing slot in the bolt plug.
9. Compress the firing pin spring and remove the firing pin, the firing pin spring and the bolt plug. **Watch out! The spring has some tension***
1. Replace the extractor.
2. Slide the locking sleeve with the lugs in front over the cylinder.
3. Replace the cocking piece and slide it into the firing groove in the bolt plug.
4. Replace the firing pin spring over the cocking piece and compress it and hold.
5. Replace the firing pin, release the spring.
6. Pull and turn the cocking piece so that the rear rests between two slots in the bolt plug.
7. With the cylinder/locking sleeve assembly in the left hand, hold the locking lugs with the thumb and middle finger. Align the ejector slots in the locking sleeve and the cylinder and hold them aligned with the tip of the index finger.
This shows the ejector slots lined up. (Sorry for the bad pic)
8. Slide the sleeve/cylinder assembly into the firing mechanism assembly until it bottoms, with the cam follower plate in the bolt plug turned to the left. Turn the sleeve/cylinder assembly a quarter turn until the sear pocket of the helical slot in the locking sleeve aligns with the cam follower plate slot in the bolt plug.
9. Replace the cam follower plate by inserting the rear end of the plate in the cam follower plate slot in the bolt plug; Slide the cam follower plate back until it bottoms and turn the bolt to the left until the cam follower pin can slide into the pocket on the aft end of the helical slot in the locking sleeve.
10. Place the Cocking Piece Sear in the safety slot in the bolt plug.
The bolt is now ready to be inserted back into the rifle.
Stock Removal
Make sure magazine has been removed.
1. Completely unscrew and remove the forward barrel band.
2. Unscrew 2-3 turns on the rear barrel band (sling loop) - *never remove completely.
3. Slide the barrel band forward and remove.
4. Remove the hand guard.
5. Remove the two screws in the magazine plate.
6. Remove the barrel from the stock by grasping it from the muzzle.
1. Place the barrel in the stock receiver first.
2. Replace the magazine plate.
3. Loosely tighten the magazine plate screws.
4. Final tighten the forward screw first and then the aft screw.
5. Replace the hand guard by ensuring that the metal tab engages the slot in the rear sight housing.
