Shimming the 5-Teen Bolt
The Remington 5-Teen rimfire series (510, 511,512, 513, 513-T and 521-T) rifles, are some of the best rimfire rifles ever produced.
Part of headspace on this rifle series is derived from the tubular sleeve the bolt handle is attached to. Remington calls this assembly the "Cocking Cam". The cocking cam is the thinnest part of the bolt assembly, and it's under mainspring pressure. When the bolt handle is raised and lowered, the front of the cocking cam tube is rubbing against a shoulder on the back side of the forward section of the bolt (the part of the bolt which actually pushes the cartridge into the chamber).
After many thousands of rounds, the front of the Cocking Cam tube may wear. As the cocking cam tube wears, the forward section of the bolt gradually moves backwards, increasing headspace a like amount. Soon, firing pin energy, normally reserved for indenting the brass cartridge case rim, is being expended to drive the cartridge case forward into the chamber more then the original specifications call for. Though it may not seem like an excessive distance, it really does matter! The end result is weak ignition, and degraded accuracy. A shooter will not be aware of a problem until the front of the cocking cam wears so much cartridges begin to misfire. What we need to do is get the forward section of the bolt closer to the chamber when the bolt handle is turned all the way down.
The cure is easy, and achieved at home with few tools and a minimum expenditure of funds.
Tools:
3/32 punch or a thin nail
12mm Deep Socket
Vice (vice is optional, but highly recommended)
Eye protection
Supplies:
Cleaning Rags
Spray Disk-Brake Cleaner
Gun Oil
Shim Set, Kyosho-96646
http://www.ebay.com/sch/i.html?_from=R40&_sacat=0&LH_BIN=1&_nkw=kyosho+96646&_sop=15
Make sure the rifle is unloaded. Remove the magazine. Remove the bolt by holding the trigger all the way back and sliding the bolt completely out.
Pad the vice jaws with cardboard, leather, aluminum, lead, etc. Gently clamp the front part of the bolt in the vice.
Wear eye protection. Don't allow any person or a pet to stand behind you for the next step.
Put a piece of thick cloth on the bolt sleeve and push the 12mm deep socket against the Bolt Sleeve. The Bolt Sleeve is under spring pressure.
Push until a 3/32 punch (or long nail) can push out the retaining pin. S-l-o-w-l-y relax pressure on the socket.
The Bolt Sleeve, Mainspring and Safety Indicator will be released from the bolt.
The remaining parts are not under pressure.
Note: these parts wil now slide out.
Lift out the Mainspring Plunger.
Lift out the Firing Pin Cam.
Slide off the Cocking Cam.
Clean all parts with spray disk-brake cleaner.
1- each. 0.1mm (.004 thousands) shim should be all that is needed to cure the vast majority of 5-teens. Slide one onto the front of the bolt.
Slide the Cocking Cam forward until it and the shim are against the front part of the bolt. Lightly oil the front part of the bolt.
Reassemble the remaining parts in reverse order.
Insure the reassembled bolt looks like this. Note: the shim can be seen between the cocking cam and the front part of the bolt.
The Remington 5-Teen rimfire series (510, 511,512, 513, 513-T and 521-T) rifles, are some of the best rimfire rifles ever produced.
Part of headspace on this rifle series is derived from the tubular sleeve the bolt handle is attached to. Remington calls this assembly the "Cocking Cam". The cocking cam is the thinnest part of the bolt assembly, and it's under mainspring pressure. When the bolt handle is raised and lowered, the front of the cocking cam tube is rubbing against a shoulder on the back side of the forward section of the bolt (the part of the bolt which actually pushes the cartridge into the chamber).
After many thousands of rounds, the front of the Cocking Cam tube may wear. As the cocking cam tube wears, the forward section of the bolt gradually moves backwards, increasing headspace a like amount. Soon, firing pin energy, normally reserved for indenting the brass cartridge case rim, is being expended to drive the cartridge case forward into the chamber more then the original specifications call for. Though it may not seem like an excessive distance, it really does matter! The end result is weak ignition, and degraded accuracy. A shooter will not be aware of a problem until the front of the cocking cam wears so much cartridges begin to misfire. What we need to do is get the forward section of the bolt closer to the chamber when the bolt handle is turned all the way down.
The cure is easy, and achieved at home with few tools and a minimum expenditure of funds.
Tools:
3/32 punch or a thin nail
12mm Deep Socket
Vice (vice is optional, but highly recommended)
Eye protection
Supplies:
Cleaning Rags
Spray Disk-Brake Cleaner
Gun Oil
Shim Set, Kyosho-96646
http://www.ebay.com/sch/i.html?_from=R40&_sacat=0&LH_BIN=1&_nkw=kyosho+96646&_sop=15
Make sure the rifle is unloaded. Remove the magazine. Remove the bolt by holding the trigger all the way back and sliding the bolt completely out.
Pad the vice jaws with cardboard, leather, aluminum, lead, etc. Gently clamp the front part of the bolt in the vice.
Wear eye protection. Don't allow any person or a pet to stand behind you for the next step.
Put a piece of thick cloth on the bolt sleeve and push the 12mm deep socket against the Bolt Sleeve. The Bolt Sleeve is under spring pressure.
Push until a 3/32 punch (or long nail) can push out the retaining pin. S-l-o-w-l-y relax pressure on the socket.
The Bolt Sleeve, Mainspring and Safety Indicator will be released from the bolt.
The remaining parts are not under pressure.
Note: these parts wil now slide out.
Lift out the Mainspring Plunger.
Lift out the Firing Pin Cam.
Slide off the Cocking Cam.
Clean all parts with spray disk-brake cleaner.
1- each. 0.1mm (.004 thousands) shim should be all that is needed to cure the vast majority of 5-teens. Slide one onto the front of the bolt.
Slide the Cocking Cam forward until it and the shim are against the front part of the bolt. Lightly oil the front part of the bolt.
Reassemble the remaining parts in reverse order.
Insure the reassembled bolt looks like this. Note: the shim can be seen between the cocking cam and the front part of the bolt.