Rimfire Central Firearm Forum banner

How To: Shim the 5-Teen Bolt

20K views 21 replies 10 participants last post by  schutzen-jager 
#1 · (Edited)
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.
 
See less See more
13
#2 ·
Hi Guys,

Here it is! How to install a shim in the bolt of a 5-teen, it's been re-written with pics.

Thanks for all your support by constantly referring to my article which was on the former JMTPublishing site. It's the support from you guys which makes the effort worthwhile. :t

Brad will make this post into a sticky.

Best Regards, Mark (ultramag44) :)
 
#5 · (Edited)
Question about the measurements

Mark.... In the article, you stated:
"I measured fired cartridge cases from properly functioning rifles. They averaged .027 thousands rim remaining after firing pin crush. Fired cartridge cases from my 513-T measured .032 thousands rim remaining after firing pin crush. My 'wand' has revealed all!"

The average was .027. What was the smallest dimension, if you remember or recorded? as low as .025? Thanks in advance! Tomon
 
#6 ·
More reference points

I just finished installing a shim in my 513T. I used a slide clamp rather than a vise, but the instructions made it a walk in the park! Also, whereas Ultramag didn't have access to headspace gauges, I bought them years ago to do this exact same thing to our Army loaned Club rifles. For future reference, my GO gauge rim measures .041 inches, and the NO-GO is slightly over .044 to my eyes. I may have to break out the digital calipers, as trying to read between lines on my old Mitutoyos is getting harder.
 
#10 · (Edited)
I just finished installing a shim in my 513T. I used a slide clamp rather than a vise, but the instructions made it a walk in the park! Also, whereas Ultramag didn't have access to headspace gauges, I bought them years ago to do this exact same thing to our Army loaned Club rifles. For future reference, my GO gauge rim measures .041 inches, and the NO-GO is slightly over .044 to my eyes. I may have to break out the digital calipers, as trying to read between lines on my old Mitutoyos is getting harder.
I took the rifle to the range yesterday to try different ammo, as the CCI Standard shot WORSE after the shim install. I had most of a brick of old Federal Gold Medal Match on the shelf, so I broke that out for the test. As soon as I can get the darned picture to upload here, I'll post it.



.
 
#11 ·
I have an old H&R 865 Plainsman that had a big headspace issue, and solved it thanks to this sticky. It took .040" worth of shims. The H&R uses a boss on the bolt handle to cam the bolt into place, using the handle as the locking lug. The receiver was worn from years of camming into place.
 
#12 · (Edited)
'ol shooter,

I'm glad it worked for your H&R! Some of the older guns have relatively soft receivers. As the engagement surfaces wear, the bolt sets back. The shim reestablishes the correct headspace.

Regards, ultramag44
 
#21 ·
....still would not recommend using shims at all -
Calfee did a couple of really good articles on rimfire headspace and ignition a few years back. He explained why adding shims to a bolt is a bad idea. Especially on an older bolt where the mating surfaces have already been worn in together. He also did a test with his Win 52 where he increased the headspace incrementally and there was no loss of accuracy until the headspace was so far are out that he started getting misfires from overly light strikes.

I have a 513T from 1946 and the headspace is a little on the sloppy side. I actually thought about shimming the bolt long before I ever heard of people doing it and a few years before I read Calfee's articles. My 513T shoots fantastic as is and I'm glad now that I never shimmed the bolt. It doesn't need it
 
#22 ·
PWnolan is 100% correct about shimming - over 6 decades of owning, researching, repairing, building, + rebuilding 5 teens i can only recall 2 or three that need headspace correction - they were all from amateur barrel replacement or built from parts - if locking lugs on bolt + matching receiver surfaces show no signs of wear headspace should be corrected by repositioning barrel - shims cause more problems than they correct, especially with regular usage -
 
Top