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  #16  
Old 05-04-2021, 09:38 AM
bchance1

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Quote:
Originally Posted by schutzen-jager View Post
bolt shims are known to definitely cause more problems + create serious safety concerns - it is a dubious and
spurious type of repair that was never recommended by factory or any knowledgeable + experienced gunsmiths with verifiable practical hands on experience - read sticky + many posts on here about shim usage - practical , safe , less time consuming+ efficient way to correct loose head space is set barrel back with procedure outlined here by many experience posters in years past on this forum -
Would it be a problem to use this as a cheap easy way to confirm the issue before undertaking a more permanent solution of setting back the barrel?
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  #17  
Old 05-04-2021, 10:30 AM
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priorities would be better directed to finding cause of problem before attempting any solutions - did you measure overall length of replacement pin compared to old one - did you clean any grime or carbon from firing pin channel that would obstruct pin protrusion ? - pin should protrude to at least even with shoulder at top of bolt face - FYI using methods for bolt lengthening recommended here can cause problems with feed + lifter timing if even slightly over done -
what do the indents on case rims look like ? - barrel set back is easier then bogus shim replacement repair - one of many barrel set back procedures that have appeared here on this forum over the years - try using search function - - if you can remove stock + two pins you can perform barrel set back , but why do it if it is not problem - have you tried using different brand + lot of ammo ? - quote from 2016 -
{{{ remove stock + bolt - drive out the two pins in front of receiver + remove barrel - clean barrel + receiver mating surfaces - apply two part epoxy to barrel stub , insert head space gauge in chamber ( a fired case from a good chamber can also be used if a gauge is not available ) install barrel + bolt , tap muzzle so it is firmly seated against bolt - let set over night - some on this forum use it as is , others redrill barrel shank + reinstall pins - i've done it both ways with no problems ] - just remember that in the future if you want to remove barrel you will need a little heat to break epoxy bond - there are several threads on here with pictures showing complete instructions - more precise + much more dependable than using bolt shims - + easier than it sounds - }}}
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  #18  
Old 05-04-2021, 10:43 AM
bchance1

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Quote:
Originally Posted by schutzen-jager View Post
priorities would be better directed to finding cause of problem before attempting any solutions - did you measure overall length of replacement pin compared to old one - did you clean any grime or carbon from firing pin channel that would obstruct pin protrusion ? - pin should protrude to at least even with shoulder at top of bolt face - FYI using methods for bolt lengthening recommended here can cause problems with feed + lifter timing if even slightly over done -
what do the indents on case rims look like ? - barrel set back is easier then bogus shim replacement repair - one of many barrel set back procedures that have appeared here on this forum over the years - try using search function - - if you can remove stock + two pins you can perform barrel set back , but why do it if it is not problem - have you tried using different brand + lot of ammo ? - quote from 2016 -
{{{ remove stock + bolt - drive out the two pins in front of receiver + remove barrel - clean barrel + receiver mating surfaces - apply two part epoxy to barrel stub , insert head space gauge in chamber ( a fired case from a good chamber can also be used if a gauge is not available ) install barrel + bolt , tap muzzle so it is firmly seated against bolt - let set over night - some on this forum use it as is , others redrill barrel shank + reinstall pins - i've done it both ways with no problems ] - just remember that in the future if you want to remove barrel you will need a little heat to break epoxy bond - there are several threads on here with pictures showing complete instructions - more precise + much more dependable than using bolt shims - + easier than it sounds - }}}
1)I will disassemble and measure the two pins. Do you happen to know a correct measurement for reference?
2) Firing pin channel is totally clean
3) I will check protrusion of firing pins. Anyone happen to have a working model measurement of protrusion that I can reference?
4)As I said on here if I didn't know one fired and one didn't I would say they were the same firing marks. if lighter its not by much at all.
5)as I have said on here I have tried different ammo and confirmed that ammo valid in different guns.
6) I have found threads that you quote that set back process. I have not been able to find any photo walkthroughs which is what I was referring to. So apparently my search-foo is not that great.
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  #19  
Old 05-04-2021, 12:08 PM
WalnutBill22
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I was having a similar problem as yours with an old M521-T (same action as yours), so I tried the bolt shim technique as described in one of the stickies above (by ultramag 44). It worked for me. I don't recall a single misfire since I did it, and accuracy improved somewhat as well. It was fairly quick and easy to do.
This may not be a factory suggested fix, and the barrel set-back technique may be better, but it's hard to argue with success.
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  #20  
Old 05-04-2021, 01:50 PM
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like other contributors here have found success with bolt shims over the years is usually short lived under regular + constant use - spend a few hours removing a stuck bolt do to a split or broken shim or have a accidental discharge on rapid bolt closing because of too thick shim + you will never use bolt shims again
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  #21  
Old 05-04-2021, 02:00 PM
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new pin length = 3.723 -
like i stated pin should protrude from un cocked bolt even with ridge on upper part of bolt face -
i have no pictures of barrel set back procedure but it is a simple process to follow by description - i can not find the old postings with pictures -
do the cases that fired in other rifles have a similar indent to the ones that are not firing in this one ?

if head space is excessive most of the time the rimfire case head where it meets case body or in center it will appear bulged or swollen -
the only models of this type that i have encountered wiht excess head space were GI used 513's + 521's with bolts replaced during rebuilds or put together parts guns from surplus barreled actions -

Last edited by schutzen-jager; 05-04-2021 at 02:09 PM. Reason: spelling
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  #22  
Old 05-04-2021, 04:08 PM
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The rim thickness of a 22 rimfire case is from .037 to .042"s. Head space should be from .044 to .049". Ideally head space would be .044" which would give a space of .002". But you need to find head space gauges for a 22LR and see where you are at. If your bolt closes on the No-Go gauge then you have too much headspace. Using shim stock you can determine how much excess headspace you have by adding shims until you can't close the bolt. This is done in thousands of an inch.

Stainless steel shims can be made from shim stock that can be bought from an automotive store. This will take hand work and some needle filing. They would go between the bolt handle body and the forward bolt section. They would look like a washer.

With the correct headspace you should have .065" of firing pin sticking out of the bolt face. If you do not have .065 sticking out of the bolt face your problem is the firing pin is too short. Then you have to get a longer pin OR have the firing pin put in a lathe and take off a few thousands of an inch to make it correct. BUT you should check and see if there is a reason for the short firing pin. The pins are peened into the firing pin body. It is probably just a simple touch up with a small file to take down the portion of the peening that is sticking up and keeping your firing pin from protruding out enough.

Now some will say the generally used method of headspacing that I outlined say it is dangerous, but no one has said why. They will advocate that you need to set the barrel back and recut your chamber and extractor notches. That is fine on a threaded barrel but on a pinned barrel like the 512 it is not practical or even advised. It just shows that they don't understand how the 512 is made.
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  #23  
Old 05-04-2021, 04:21 PM
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FYI

factory tolerances on many head space gauges vary by more then .002 - specs on firing pin protrusion varies with manufacturers , models , bolt , + sometimes chamber designs + extractor cuts - one set of measurements can never apply to all applications -
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  #24  
Old 05-04-2021, 05:36 PM
WalnutBill22
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Quote:
Originally Posted by jpickar View Post
The rim thickness of a 22 rimfire case is from .037 to .042"s. Head space should be from .044 to .049". Ideally head space would be .044" which would give a space of .002". But you need to find head space gauges for a 22LR and see where you are at. If your bolt closes on the No-Go gauge then you have too much headspace. Using shim stock you can determine how much excess headspace you have by adding shims until you can't close the bolt. This is done in thousands of an inch.

Stainless steel shims can be made from shim stock that can be bought from an automotive store. This will take hand work and some needle filing. They would go between the bolt handle body and the forward bolt section. They would look like a washer.

With the correct headspace you should have .065" of firing pin sticking out of the bolt face. If you do not have .065 sticking out of the bolt face your problem is the firing pin is too short. Then you have to get a longer pin OR have the firing pin put in a lathe and take off a few thousands of an inch to make it correct. BUT you should check and see if there is a reason for the short firing pin. The pins are peened into the firing pin body. It is probably just a simple touch up with a small file to take down the portion of the peening that is sticking up and keeping your firing pin from protruding out enough.

Now some will say the generally used method of headspacing that I outlined say it is dangerous, but no one has said why. They will advocate that you need to set the barrel back and recut your chamber and extractor notches. That is fine on a threaded barrel but on a pinned barrel like the 512 it is not practical or even advised. It just shows that they don't understand how the 512 is made.
I just used the Kyosho shims (available on ebay and maybe Amazon) exactly as Ultramag illustrated in the stickie. No fitting or filing required at all. Trial and error will tell you how many (if any) you need. I believe mine only required one of the 0.2mm shims. Schuetzen may be right about long-term or high volume shooting, since I haven't shot mine a great deal after the shim treatment, but I have heard mostly success stories from a variety of bolt action rifles, including the Ruger 77/22 and a few others.
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  #25  
Old 05-04-2021, 07:31 PM
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For a cheap, easy, safe test try forcing the closed bolt forward while firing shots. Hold rifle normally and use right thumb to push forward with some force on bolt handle. This should reduce headspace and improve your 75% success rate. If it does then worry about shims or barrel set back.

I have s used the Kyosho shims on a couple of 511's with no problems. That said, they have not had a lot of rounds through them yet.
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  #26  
Old 05-05-2021, 06:07 AM
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shims

definitely - a short term jury rig type of repair l - like walnut bill + hushcaboom stated the ones they have shims in have seen little use - the 3 + broken split ones i have encountered were in DCM + CMP rifles that were used extensively by boy scout camps , 4h , + junior rifle clubs - remember that by using those shims you are putting rotational , forward , + backward thrust on what is basically a thin piece of foil not designed for that purpose - if indeed the OP's problem is loose head space setting barrel back for a lasting safe repair makes much more sense then any shim when reliability + safety are a concern of the user - the more components in any mechanisms just provide more opportunities for failures + break downs then less , simpler , + more substantial better constructed parts + proven repairs -

Last edited by schutzen-jager; 05-05-2021 at 06:25 AM. Reason: addendum
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  #27  
Old 05-05-2021, 11:38 AM
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Quote:
Originally Posted by jpickar View Post
The rim thickness of a 22 rimfire case is from .037 to .042"s. Head space should be from .044 to .049". Ideally head space would be .044" which would give a space of .002". But you need to find head space gauges for a 22LR and see where you are at. If your bolt closes on the No-Go gauge then you have too much headspace. Using shim stock you can determine how much excess headspace you have by adding shims until you can't close the bolt. This is done in thousands of an inch.

Stainless steel shims can be made from shim stock that can be bought from an automotive store. This will take hand work and some needle filing. They would go between the bolt handle body and the forward bolt section. They would look like a washer.

With the correct headspace you should have .065" of firing pin sticking out of the bolt face. If you do not have .065 sticking out of the bolt face your problem is the firing pin is too short. Then you have to get a longer pin OR have the firing pin put in a lathe and take off a few thousands of an inch to make it correct. BUT you should check and see if there is a reason for the short firing pin. The pins are peened into the firing pin body. It is probably just a simple touch up with a small file to take down the portion of the peening that is sticking up and keeping your firing pin from protruding out enough.

Now some will say the generally used method of headspacing that I outlined say it is dangerous, but no one has said why. They will advocate that you need to set the barrel back and recut your chamber and extractor notches. That is fine on a threaded barrel but on a pinned barrel like the 512 it is not practical or even advised. It just shows that they don't understand how the 512 is made.
can you publish a creditable source for your figures ? -
using a case rim gauge + a digital mic. just checked for calibration at Rutgers university lab i just measured rim thickness on 9 different age + manufacturers unfired cases in groups of 6 same lot samples - smallest rim thickness was .018 + largest was .025 - average of .022 -
check firing pin protrusion on bolts of 12 different 510 thru 521 bolts - ranged from .036 to .043 with average of .039 -
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  #28  
Old 05-05-2021, 01:09 PM
jpickar

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Quote:
Originally Posted by schutzen-jager View Post
can you publish a creditable source for your figures ? -
using a case rim gauge + a digital mic. just checked for calibration at Rutgers university lab i just measured rim thickness on 9 different age + manufacturers unfired cases in groups of 6 same lot samples - smallest rim thickness was .018 + largest was .025 - average of .022 -
check firing pin protrusion on bolts of 12 different 510 thru 521 bolts - ranged from .036 to .043 with average of .039 -
Google it dude!

Last edited by jpickar; 05-05-2021 at 01:59 PM.
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  #29  
Old 05-05-2021, 01:23 PM
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jpicker what you say must be tue because you saw it in internet

Quote:
Originally Posted by jpickar View Post
Google it dude!
my findings are base on actual readings based on calibrated instruments + decades of hands on experience + not hearsay + uneducated dubious opinions -

been called a lot of things on this forum over the years , but never before a troll !!!

this published data coincides very closely to my measurements -
http://bulletin.accurateshooter.com/...-length-gauge/

Last edited by schutzen-jager; 05-05-2021 at 01:56 PM. Reason: addendum
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  #30  
Old 05-05-2021, 03:15 PM
williwm
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From the site linked the chart shown has nothing to do with rim thickness. The figures shown are the base of the rims to the ogives measurements, not rim thickness. Looking at the Federal champion and reading rim thickness as .008” to .014” is not correct

The article is advertising two different tools.
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