Win 52B Safety/Trigger Info - RimfireCentral.com Forums

Go Back   RimfireCentral.com Forums > > >

Notices

Join Team RFC to remove these ads.
Reply
 
Thread Tools Display Modes
  #1  
Old 06-28-2012, 09:19 PM
Scot Thompson

Join Date: 
Jul 2011
Location: 
Western North Carolina
Posts: 
171
TPC Rating: 
0% (0)
Win 52B Safety/Trigger Info



Log in to see fewer ads
Notes: [The public link to the photos is:
http://s1247.photobucket.com/albums/...ScotThompson1/

Essential to this discussion is the original patent. I have it in .pdf format, but I can't upload it.

Had to cut the trigger adjustment and make it a second posting. As well as the parts list off.]

The Winchester Model 52B has a common complaint about its safety. In my case, the safety’s thumb slide could hardly be forced into its engaged position. When it was engaged and the trigger pulled once, the rifle would fire without touching the trigger when the safety was disengaged. There are several manifestations of this problem: the safety is hard or even impossible to engage, the thumb slide may be bent from attempts to engage it; with the safety engaged and the trigger pulled, a slight click is heard and felt and when the safety is then disengaged, the gun fires without further pressure on the trigger; there are frequent fail-to-fires with this problem; the trigger pull-force is quite high, the trigger does not respond to adjustment as designed. The source of the problem is disguised because the rifle continues to fire. However, in my opinion, this problem will eventually result in a firing pin that will not be able to remain cocked.

Upon realizing my gun had a problem, I turned to the shooting community to find out what was wrong. I especially leaned on the RimFire Central group. I even wrote to known gunsmiths and took the gun to local help…all to no avail. It seemed the problem was known, but not the fix…or even the cause of the problem for that matter. From YouTube to the shooting forums, the message was, “this is an unfixable problem.” However, there were one or two comments that some had experienced this years ago and took it to their gunsmith and he fixed it. No word as to what they did, and I did my best to chase down those gunsmiths…but without success. Still, if it could be fixed….

I am not a gunsmith and have no training in gun repair, so please decide for yourself if anything thing I present or conclude has merit. If you act on any of the following conclusions, please do so for yourself.

[img]http://i1247.photobucket.com/albums/gg627/ScotThompson1/OldandNewFiringPinsASmall.jpg[img]

Okay, so let me give you the bottom line and the fix right now and the explanation later. The problem with the Win 52B that has the symptoms stated above is the firing pin is worn. The fix is to replace the firing pin. I replaced the main spring as well. I made the tools per the Sticky in the RFC Win 52 forum. (I made a belly tool modification to replicate the needed 3rd hand…picture later.) The main spring I bought from Barnes (barnesgunparts.com) – “Winchester 52 Match Firing Pin Spring”, no P/N, for $9.99 and the replacement firing pin I bought from Numrich (gunpartscorp.com), P/N 1158150 Winchester 52B Firing Pin for $47.50. That’s it! Understanding the problem takes some time, but the fix is quite easy. Be advised there are some other parts of the trigger assembly that may cause a similar problem and I’ll mention them later, but in the two cases I worked on, these parts fixed the problem. And, the trigger pull force was greatly reduced due to understanding how the trigger adjustment should be made.

To identify the problem, I researched the history of the Winchester Model 52 and quickly discovered that the Win 52 B model stands alone in its trigger assembly. There is a familiar book, “The Winchester Model 52 – Perfection in Design” written by Herbert G. Houze that is a terrific and interesting resource on the Win 52. But it did not shed any light on the problem with the Win 52 B. I turned to the U.S. Patent Office to research the patent for the Win 52 itself and there, as a public record, are the patents for the Win 52. Of specific interest was a reference for the Win 52B. A Winchester employee by the name of A.F. Laudensack filed a patent 2,069,887 for “Sear Mechanism for Firearms” on July 31, 1937. This is the patent for the trigger and sear for the Win 52 B. It does not contain references to the safety, but as will become apparent, the problem does not lie with the safety. I found that when the safety does not engage properly, it is an indication that something else has worn. The entire patent is attached [at least I want to attach it!] to this document and I use the part reference numbers on the patent to describe the problem and also how to adjust the trigger. I also compiled a cross reference of each part named in the patent with its number referenced in the patent. Please note that the numbering scheme used by Houze does not correlate to that used by Laudensack. The patent is the source of the design and clearly describes the functioning of the bolt, firing pin, the sear and all its parts, and the trigger and very detailed drawings are included.
I want to give thanks and appreciation to an accomplished gunsmith, benchrest shooter, and a fine gentleman by the name of Dan Stone of Round Lake, IL. Dan is a long standing member, and director, of the Illinois State Rifle Association and he is a member of RimFire Central. Dan gave me unlimited advice, guidance and suggestions in the pursuit of the solution to this problem as we chased down many ideas and burned up the e-mail electrons before pinning down the actual cause. Dan is an amateur gunsmith by avocation, but he is very knowledgeable. Dan Stone is willing to repair Win 52Bs with this problem; if you need help with your gun, google Dan Stone of Round Lake, IL. I would also like to thank another person by the name of Bruce Lutz. Bruce lives in Colorado and is a member of RFC as well as a committed rimfire benchrest shooter. Bruce has a Win 52B very close to mine in S/N and it exhibited the same problems as mine did. We used Bruce’s rifle to be the unaltered, zero-reference as we explored potential solutions with my rifle. After my rifle was fixed, Bruce then made the same repairs and adjustments to his rifle…with the same success! And by the way, we both now have Win 52Bs with trigger pulls around 1 lb-8 oz and our safeties work as designed.

THE WINCHESTER 52B TRIGGER
Here are pictures of the Win 52 B trigger still mounted on the receiver. Note the Trigger #54 and the Sear #46 are contained in a Trigger Bracket #70 – reference the patent for the numbering.

Figure 1 Left Side of Trigger Assembly

Figure 2 Right Side of Trigger Assembly
On the Win 52B, there is a Trigger Adjusting Screw #77 that is accessible through an access hole when the bolt is removed from the receiver. It is seen as the spring/screw assembly angled of the rear of the trigger. The purpose of this screw is to fine tune the trigger pull weight. In fact, this is not the primary trigger adjustment at all, that being the function of a part called the Inclined Adjusting Screw #57. The Screw #57 is not seen in the above photos, but it controls the overlap of the sear and trigger Shoulders #55 and #56 and that is what regulates the force necessary to release the firing pin. The #77 Screw is just a fine tuning device. I’ll discuss setting the trigger in more depth later.

Figure 3 Adjustment screws for Win 52B Trigger
THE WINCHESTER 52B SAFETY
This problem more often than not shows up as a malfunctioning safety. How did this safety come about? Both the U.S. patents and Houze’s book shed some light. In 1934, Winchester apparently determined to improve on the Speed Lock, the original lock design for the Win 52 and 52A. Captain Albert F. Laudensack was deeply engaged in the Win 52 project and he created a new lock (and safety) design for the Win 52. This Type B was destined to replace the Type A. [Refer to the patent for the parts numbering I reference as follows. The insert within square brackets are my comments.] Quoting from Houze, “In contrast [to an alternative design created by Russell Wiles that was not implemented], Laudensack’s design closely resembled that of the Speed Lock and, therefore, only required minor structural alterations in the Model 52’s receiver to allow its usage. In form the new lock mechanism differed from its predecessor in four respects: the trigger spring [#78] was mounted on an adjustable set screw [#77] secured in place by a flange projecting from the rear face of the trigger housing [the Trigger Bracket #70], the sear [#46] was fitted with a spring-loaded plunger [#60] to insure disengagement from either the firing pin or safety (when released), the adjustment screw [the Inclined Adjusting Screw #57] for setting the amount of platform available on the trigger-sear support ledge [this is the overlap of the Trigger-engaging Shoulder #55 with the Sear-engaging Shoulder #56] was mounted internally so it could only be turned when the action was dismounted, and most noticeable, a sliding safety was installed in place of Burton’s original rotating wing catch.” Houze further states, “In addition to ease of manipulation, this safety’s mechanics also were a marked improvement over those employed earlier. Instead of locking the firing pin head in the cocked position, Laudensack’s safety disengaged the sear from the trigger. This was accomplished by a sliding plate connected to the safety lever [the thumb lever]. When the firing pin was cocked, rearward pressure on the lever caused the plate to similarly mover rearward. As it did, the plate slid alongside the sear and a slot cut in the plate’s side engaged a pin projecting out from the sear itself. Further pressure on the lever resulted in the pin enter the plate cut, forcing the sear upward slightly as the pin rode within the channel. When the safety was fully applied, the slide plate prevented any movement of the sear, thereby locking the firing pin and bolt in place. The singular advantage of this safety’s design was that it positively locked the firing pin while at the same time releasing the trigger from all contact with the sear.”

Figure 4 Win 52B Safety in Off Position

Figure 5 Win 52B Safety Engaged

Figure 6 Thumb Safety and Sliding Plate

Figure 7 Win 52B Safety - Slot Captures and Lifts Sear
Whew! That is a mouthful! But it contains all the critical ingredients necessary to understand the functioning of the Win 52B safety. Let me pick it apart: The Win 52B trigger has an adjustable set screw accessible when the bolt is removed. This is the #77 screw that puts forward pressure on the rear of the trigger itself. Important, but in my opinion this is not the key element to trigger adjustment. That “spring-loaded plunger” referred to in the above paragraph is the little ball bearing looking device visible just inside the receiver when the bolt is removed. It fits up into the detent in the underside of the bolt. It is referred to as the Sear-Activating Plunger #60 in the patent. Its purpose is to put downward pressure on the rear of the sear when the bolt is rotated into cocked position, causing it to rotate.

Figure 8 Bolt Removed to Show Sear-Activating Plunger
In effect, the rear of the Sear #46 moves downward when the bolt is cocked. This is important because the downward motion of the rear of the sear is what brings the two shoulders (#55 and #56) together – bear with me a minute longer. When the safety’s thumb lever is moved rearward, it also slides a plate that has a slot in towards the rear. This slot captures a pin [there is no number for this pin on the patent but if you look just to the forward of the #63 spring in Figure 3 of the patent, it is visible] and the slot actually lifts the sear by engaging that fixed pin thereby disengaging the two shoulders #55 and #56 and simultaneously securing the sear so that it cannot move upward or downward until the safety is disengaged. See the above Figures 4, 5, 6, and 7. Why is this important? Well, with the two shoulders #55 and #56 not in contact with each other, pulling the trigger (Shoulder #56) should have no impact on releasing the sear because it is not touching the sear (Shoulder #56) when the safety is properly engaged. At the same time, because the safety firmly captures and lifts the sear, it forces the Sear Nose #45 upward into the firing pin thereby increasing the overlap of the Rear Face #44 of the Sear Nose with the Forward Facing Cocking Shoulder #43 of the firing pin. This dual function of separating the trigger from the sear while increasing the platform overlap of the sear nose with the firing pin is what Houze means when he stated, “The singular advantage of this safety’s design was that it positively locked the firing pin while at the same time releasing the trigger from all contact with the sear.”

Figure 9 Win 52B Trigger/Sear Assembly, Bolt with Firing Pin

Figure 10 Win 52B Sear with Fixed Pin

Figure 11 With Bolt Cocked, Firing Pin Has Slipped Past the Sear Nose, Forcing the Sear's Pin to drop below the Safety Slot. This is Why the Safety Becomes Difficult to Engage, It Can No Longer Engage the Pin and Lift the Sear As it Was Designed to Do.

Figure 12 Win 52B Firing Pin and Mainspring
So, if that is what is supposed to happen when the safety is engaged, what is actually taking place when the Win 52B safety problem arises? It is first important to understand that the Win 52B safety is designed such that it cannot be engaged unless the firing pin is cocked. Close and rotate the bolt while holding the trigger, or simply pull the trigger to release the firing pin and try to engage the safety. It cannot be done because when the firing pin is in its released position (fired position) the top of the Sear Nose #45 is rubbing against the bottom of the firing pin – look at the differences between patent Figures #3 and #5 where the Sear Nose #45 is in relation to the Firing Pin #30.
When the Win 52B safety problem manifests itself the Sear Nose #45 has slipped past the Forward Facing Cocking Shoulder #43 of the firing pin; i.e., the Rear Face #44 of the sear nose fails to catch its mating shoulder (face) of the firing pin. The Firing Pin #30 moves very slightly forward relative to the Sear Nose #45 until the firing pin becomes wedged between the sear nose and the chamber the firing pin resides in. See the photo below depicting the wear of the Face #44 of the firing pin. Once the firing pin is wedged against the top of the sear nose, the Sear #46 is no longer in the correct position to allow the safety plate slot to engage the fixed pin on the side of the sear. Rather, the fixed pin on the side of the sear is too low to be captured by the safety’s sliding plate slot. This is why the safety becomes difficult to engage. It can no longer engage the pin and lift the sear as it was designed to do because the sear is now firmly wedged against the bottom of the firing pin.

Figure 13 Forward Face #44 - edge is worn and Sear Nose misses this face and rides up on the firing pin, wedging it
When the firing pin slips past the sear nose, the firing pin is being held partially cocked – depending on how much wear has taken place, the sear is not properly captured and lifted by the safety, and the Sear Shoulder #55 remains forcefully engaged with the Trigger Shoulder #56. If you pull the trigger under this condition, the #55 and #56 shoulders disengage (you can hear and feel a small click) yet the gun will not fire because the sear nose remains wedged against the firing pin. If your wear is such that the safety’s sliding plate slot is still able to actually capture the fixed pin on the side of the sear, when you release the safety (probably hard to engage and hard to release), the firing pin will instantly be released because there is nothing to prevent the sear nose from moving downward away from the firing pin. This is not a safe condition. And, with enough wear of the bottom of the firing pin caused by the much harder sear nose, eventually, the firing pin will slide so far forward as to let the sear nose go up into the Longitudinal Clearance Slot #36. When this happens, the firing pin will no longer be able to be cocked and the gun will not fire at all. I.e., this problem will eventually disable the rifle.
The Remedy for the Win 52B Safety
As I stated in the beginning, the remedy to the Win 52B difficult-to-engage safety and associated misfires, fail-to-fires, drop fires, etc. is the worn interface between the firing pin and the sear’s nose. The Sear is made of vey high carbon steel and the firing pin is much softer so most of the wear occurs on the firing pin. Replace the firing pin and the sear nose will catch the firing pin as designed and then the safety will function and the misfires should stop. And you’ll be finally able to adjust your trigger properly. You might want to replace the main spring as well, but if you are mostly firing, then the spring is probably okay. In my gun, someone had replaced the main spring with a longer spring. I believe this was an attempt to correct the misfires; but it is exactly the wrong thing to do as it will cause even faster wear of the Forward Facing Cocking Shoulder #43 of the firing pin. The main spring is cheap and available. Replacing it is a no brainer.
I started tackling this problem by investigating the trigger assembly. I am glad I did, but the truth is, this is a bolt problem and probably you won’t even have to take the action out of the wood to fix the gun! If you have the tools (see RFC sticky: 52 Bolt Disassembly Tool) and a new firing pin and main spring, and know what you are doing, this fix can be made in about an hour or two. Just dismantle the bolt per the RFC sticky and clean your parts, lubricate properly, test fit the new parts (I had to slightly ream the Firing Spring Chamber #31 to get the spring to seat), and re-install everything. The sticky is quite clear, but make sure to read the secondary reference within the sticky as those tools are easier to make for the novice. You’ll need a good vice and the first time you compress the main spring, it takes a surprising amount of force. Just lube it and compress it several times before you actually try to remove the Pin #34 (remember, I am using Laudensack’s numbering, not Houze’s). I made my spring compressing tool out of a punch and cut the slot in the end with a Dremel cutoff wheel. The other end of this punch I fitted into a ¼” hole drilled into a piece of scrap wood. Because the spring has to be compressed and then the Pin #34 driven out of the Firing Pin #30, you need two hands to hold the little punch and hammer out the pin. You need a third hand to compress the spring and a fourth to catch the pin. Use a bucket to catch the pin. I used my stomach to compress the spring and that is why I fitted a board to the push side of the spring compressing tool. See my pictures below.

Figure 14 Belly Tool and Copper Spacer - Side View

Figure 15 Belly Tool and Copper Spacer Front View

Figure 16 Belly Tool and Copper Spacer Top View
When cleaning and lubricating the bolt, get it real clean with solvent. I used auto painters cleaning solvent and soaked in for several hours. I used compressed air to blow out the shell extractors and dry the entire dismantled bolt. I then flushed the bolt and all the parts, including the firing pin, with Naptha (lighter fluid). This leaves a slight film that is perfect for lubing and protecting the firing pin and the main spring. Do not get oil or grease on the firing pin, I wiped the bolt with gun oil to protect the metal and wiped it off to just leave a slight film. The extractors need to be lubricated with gun oil at their pivot points. The sliding and rotating parts of the bolt need a moly grease…very slight amount. Do not get lubricant on any part of the sear, trigger or firing pin that have shoulders that slip apart to function…just use the lighter fluid.
Reply With Quote
  #2  
Old 06-29-2012, 09:06 AM
z06
US Navy Veteran NRA Member - Click Here To Join!

Join Date: 
Dec 2010
Location: 
montana
Posts: 
279
TPC Rating: 
100% (1)
Hi Scot,

Thanks for taking the time to share this information! I've made a copy and it's in my "52" notebook.

Gary
Reply With Quote
  #3  
Old 06-29-2012, 11:30 AM
Savagenut's Avatar
Savagenut

Join Date: 
May 2008
Location: 
Belleville , Illinois
Posts: 
1,569
TPC Rating: 
0% (0)
Great info ; thank you !! This should be a Sticky !
Reply With Quote
Sponsored Links
Advertisement
 
  #4  
Old 06-29-2012, 01:30 PM
Dollar Bill
US Army Disabled American Veteran NRA Member - Click Here To Join!

Join Date: 
Apr 2010
Location: 
Huntsville, Alabama
Posts: 
1,115
TPC Rating: 
100% (1)
Quote:
Originally Posted by savagenut View Post
Great info ; thank you !! This should be a Sticky !
Agreed!

I have a 52B enroute, should be here today. Your research and this post are an asset to the community. Thanks!
Reply With Quote
  #5  
Old 06-29-2012, 05:41 PM
z06
US Navy Veteran NRA Member - Click Here To Join!

Join Date: 
Dec 2010
Location: 
montana
Posts: 
279
TPC Rating: 
100% (1)
Dollar Bill

Quote:
Originally Posted by Dollar Bill View Post
Agreed!

I have a 52B enroute, should be here today. Your research and this post are an asset to the community. Thanks!
I just did some trading and acquired a B. I've got it all cleaned up etc. and hope to to some shooting with it this weekend. Put a Vaver on the rear and a Redfield 63 on the front. I'm hoping to do as well as Brer Rabbit with his new C

Last edited by z06; 07-03-2012 at 09:22 AM.
Reply With Quote
  #6  
Old 06-30-2012, 08:51 AM
Scot Thompson

Join Date: 
Jul 2011
Location: 
Western North Carolina
Posts: 
171
TPC Rating: 
0% (0)
Hi shooters, thanks for the comments.

I really need to get the patent uploaded somehow. It has marvelous drawings and a good description. Does anyone know how to uploaded a .pdf file?

Bill, I use both a scope and iron sights. I took a -20MOA EWG mount and cut the rear 1/2" off so it clears the original Marble-Goss iron sight and that allow me to mount a scope or put the M-G sight back on. Alignment seems to stay right on. Surprisingly, it shoots an inch at 100 yds, 1/2" at 50 yds, and single holes at 25 yds..with either scope or the irons! The difference is the wind, when scoped I manage the wind better. My scopes are Vortex Crossfires, one is a 4X12-40 AO, and the other is an 8X32-50 AO. I'll put a pic in the online album. Scot
Reply With Quote
  #7  
Old 06-30-2012, 09:23 AM
Scot Thompson

Join Date: 
Jul 2011
Location: 
Western North Carolina
Posts: 
171
TPC Rating: 
0% (0)
I have the whole article, complete with the pics in .pdf format. And the patent as well. Assuming i don't get overwhelmed, if you PM me with you email address, I'll send you the files. These are much tidier than saving the posts. Scot
Reply With Quote
  #8  
Old 06-30-2012, 01:31 PM
mgb8345's Avatar
mgb8345
US Army Veteran NRA Member - Click Here To Join!

Join Date: 
Mar 2009
Location: 
Tucson, AZ
Posts: 
2,341
TPC Rating: 
100% (57)
Send a message via Yahoo to mgb8345
PM sent - Thanks very much Scott. Bob
Reply With Quote
  #9  
Old 08-01-2012, 10:56 AM
JWA's Avatar
JWA

Join Date: 
Jan 2010
Location: 
32,000 ft+
Posts: 
5,240
TPC Rating: 
100% (4)
Here are the patent images for Scot's very informative article. They are downloadable from this RFC thread by right clicking on the image and following the menu instructions.

Regards,















Reply With Quote
  #10  
Old 02-10-2013, 09:33 AM
Scot Thompson

Join Date: 
Jul 2011
Location: 
Western North Carolina
Posts: 
171
TPC Rating: 
0% (0)
For WPShooter

Here is one of the posts on the 52B trigger and safety. Scot
Reply With Quote
  #11  
Old 02-10-2013, 11:46 AM
2mene22s's Avatar
2mene22s

Join Date: 
Apr 2009
Location: 
Somewheres in Texas
Posts: 
6,782
TPC Rating: 
100% (23)
This needs to be a sticky !!
Reply With Quote
  #12  
Old 02-10-2013, 01:11 PM
JWA's Avatar
JWA

Join Date: 
Jan 2010
Location: 
32,000 ft+
Posts: 
5,240
TPC Rating: 
100% (4)
Quote:
Originally Posted by 2mene22s View Post
This needs to be a sticky !!
I agree, PM jGEE and let him know. He hasn't been on for several days but he can take care of it.

Regards,
Reply With Quote
  #13  
Old 11-03-2013, 12:20 PM
cruisor

Join Date: 
Apr 2008
Posts: 
2
TPC Rating: 
0% (0)
Win 52B Safety/Trigger Info

Hello Scot,

I just purchased a 52B and am going to pick it up this Wednesday. The owner stated that the safety didn't work so this information is very timely. Would you please send me the .pdf files for your solution to the problem. Please email to

cruisor @ msn.com

Thanks for your efforts to resolve this problem. I can see it would have taken a great deal of time to find and then fix it. Adding the photo's made it so much easier to understand the fix.

Thanks again,

Lee Whiteley
Reply With Quote
  #14  
Old 11-05-2013, 07:36 AM
Scot Thompson

Join Date: 
Jul 2011
Location: 
Western North Carolina
Posts: 
171
TPC Rating: 
0% (0)
Lee, I'll send out the files later today. The is another aspect of the B safety not discussed in my files. That is if the safety slides rearward easily, but will not remain in the "on" position...but functions if you hold it there. There are a probably several causes of this, but one is an improper relationship between the fixed pin on the sear and the Safety Slot that moves rearward to capture, and lift, that fixed pin. Winchester used shim washers to adjust that relationship. The shim washers went between the trigger housing and the rear attachment point of the trigger housing to the receiver. I.e., it fits under the rear mounting screw. So far it has been observed between 1 and 3 washers of 0.010" thickness each. Just enough to provide sufficient resistance to the thumb safety so it clicks into the "on" position. I had one that had a 0.008" washer. I increased it to 0.016" and then it functioned fine.
Reply With Quote
  #15  
Old 11-06-2013, 10:26 PM
BobSc
US Army Veteran

Join Date: 
Dec 2012
Location: 
Oregon
Posts: 
979
TPC Rating: 
100% (1)
Scot, could I also get a copy of the files? I have a B that also has this problem occasionally and I would like to know the fix.

Thanks,
Bob
[email protected]
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off




All times are GMT -5. The time now is 11:13 PM.

Privacy Policy

DMCA Notice

Powered by vBulletin
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
Search Engine Optimisation provided by DragonByte SEO (Lite) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
Copyright ©2000-2018 RimfireCentral.com
x