Rimfire troubleshooting decision tree

Rifle-specific details:
The short answer
Check the cheap, likely causes first: ammo, magazine, dirt, and screw torque. Change one variable at a time. Rifle-specific known problems and fixes are on the known issues page.

Safety: unload the rifle, remove the magazine and check the chamber before inspecting anything. After a misfire, keep the muzzle pointed safely downrange for at least 30 seconds before opening the action.

These are general rimfire diagnostic steps (conf: med). Rifle-specific claims with sources are on the linked pages.

Tikka T1x

Won't feed / nose-dives
  1. Is the magazine fully seated and clean? Try a second mag.
  2. Is the round seated in the mag with the rim at the back? .22 LR rims can stack (rimlock).
  3. Does it feed by hand with a different ammo brand? Some bullet shapes feed worse.
  4. Dirty or burred feed ramp/chamber mouth: clean it, then inspect.

Still stuck? See known T1x issues and the gunsmithing specs. Parts: magazines and more.

Won't extract
  1. Is the chamber fouled? Clean it with a chamber brush; dirty chambers grip cases.
  2. Is the extractor claw chipped, or is its spring weak? Inspect it with the bolt out.
  3. Is it only with one ammo lot? Tight-chamber rifles can stick on some brands.

Still stuck? See known T1x issues and the gunsmithing specs. Parts: bolt and more.

Weak or no ejection
  1. Work the bolt briskly. Rimfire bolt guns need a firm pull to eject.
  2. Is the ejector bent or gummed up?
  3. Does a clean extractor help? Ejection depends on the extractor holding the case.

Still stuck? See known T1x issues and the gunsmithing specs. Parts: bolt and more.

Light strikes / misfires
  1. Rotate the dud 90° and re-fire (wait 30+ s with the muzzle downrange first). If it fires, suspect ammo or rim priming.
  2. Many duds in one box: change ammo first.
  3. Duds across brands: the firing-pin channel is dirty, the spring is weak, or the firing pin is worn or chipped. Clean, then inspect.
  4. Was the trigger or bolt recently modified? Check the striker spring and cocking.

Still stuck? See known T1x issues and the gunsmithing specs. Parts: bolt and more.

Accuracy fell off
  1. Check action-screw torque and scope/rail/ring torque first. Most problems are here.
  2. Same ammo lot? Change one variable at a time; test at 50 yd.
  3. Is the bore over-cleaned or freshly cleaned? Fire fouling shots.
  4. Is the barrel or stock touching? Check free-float clearance and bedding.
  5. Is the crown damaged? Inspect the muzzle and thread protector seating.

Still stuck? See known T1x issues and the gunsmithing specs. Parts: accuracy and more.

Bolt is stiff, sticks or won't close
  1. Is there debris or dried lube on the bolt body or cocking cam? Clean and lightly lube.
  2. Is a case rim or brass shaving in the chamber or the bolt face?
  3. Is the scope or rail rubbing the bolt handle? Check clearance with the scope mounted.
  4. Is there an aftermarket handle or shroud? Recheck its installation.

Still stuck? See known T1x issues and the gunsmithing specs. Parts: bolt and more.

CZ 457

Won't feed / nose-dives
  1. Is the magazine fully seated and clean? Try a second mag.
  2. Is the round seated in the mag with the rim at the back? .22 LR rims can stack (rimlock).
  3. Does it feed by hand with a different ammo brand? Some bullet shapes feed worse.
  4. Dirty or burred feed ramp/chamber mouth: clean it, then inspect.

Still stuck? See known 457 issues and the gunsmithing specs. Parts: magazines and more.

Won't extract
  1. Is the chamber fouled? Clean it with a chamber brush; dirty chambers grip cases.
  2. Is the extractor claw chipped, or is its spring weak? Inspect it with the bolt out.
  3. Is it only with one ammo lot? Tight-chamber rifles can stick on some brands.

Still stuck? See known 457 issues and the gunsmithing specs. Parts: bolt and more.

Weak or no ejection
  1. Work the bolt briskly. Rimfire bolt guns need a firm pull to eject.
  2. Is the ejector bent or gummed up?
  3. Does a clean extractor help? Ejection depends on the extractor holding the case.

Still stuck? See known 457 issues and the gunsmithing specs. Parts: bolt and more.

Light strikes / misfires
  1. Rotate the dud 90° and re-fire (wait 30+ s with the muzzle downrange first). If it fires, suspect ammo or rim priming.
  2. Many duds in one box: change ammo first.
  3. Duds across brands: the firing-pin channel is dirty, the spring is weak, or the firing pin is worn or chipped. Clean, then inspect.
  4. Was the trigger or bolt recently modified? Check the striker spring and cocking.

Still stuck? See known 457 issues and the gunsmithing specs. Parts: bolt and more.

Accuracy fell off
  1. Check action-screw torque and scope/rail/ring torque first. Most problems are here.
  2. Same ammo lot? Change one variable at a time; test at 50 yd.
  3. Is the bore over-cleaned or freshly cleaned? Fire fouling shots.
  4. Is the barrel or stock touching? Check free-float clearance and bedding.
  5. Is the crown damaged? Inspect the muzzle and thread protector seating.

Still stuck? See known 457 issues and the gunsmithing specs. Parts: accuracy and more.

Bolt is stiff, sticks or won't close
  1. Is there debris or dried lube on the bolt body or cocking cam? Clean and lightly lube.
  2. Is a case rim or brass shaving in the chamber or the bolt face?
  3. Is the scope or rail rubbing the bolt handle? Check clearance with the scope mounted.
  4. Is there an aftermarket handle or shroud? Recheck its installation.

Still stuck? See known 457 issues and the gunsmithing specs. Parts: bolt and more.

Fixes and parts