Locking shoulder worked its way out a little. Cause and problems?

Sumoj275 · February 09, 2005, 20:14

Tonight a friend stoped by with a FAL that he had been shooting today. We were looking it over and I noticed the locking shoulder was sticking out further than where I had seen them on my FALs. Upon a closer look you could see where it had moved out some because it had line from where the paint was and where the shoulder had been. We broke the rifle down and looked for a cracked receiver or anything else that was out of the ordinary but could not see anything. After looking it over he used a plastic mallet head and hammered it in flush with the receiver. Now, I know this is set deeper than it was before because of the paint line. He checked the headspace and it was where he had it originally.

Now, if anyone has any ideas why it worked itself out or any experiences like this please let me know so I can relay the message.

Thanks from Dave and me

critterflht · February 09, 2005, 21:35

Possibly the LS has been taken out and put back in the rifle a couple (or more) times in the past. Every time the LS is removed or put back in, the fit will get more loose. Or, maybe it didn't fit tightly enough in the receiver to begin with because of a poor machining job on the receiver. Either way, I've never figured out how a LS could work its way out of the receiver at a right angle to the forces applied to it by the bolt, but they can. I had the problem on one of my rifles and I staked it into the receiver. Cured the problem-

Lee

Bruce Allen · February 10, 2005, 03:02

There are 4 different guages of LS, from 0 (zero) to 3.

Each is larger in size than the previous, with "0" being .297", if I recall correctly.

Most all new receivers are milled to accomodate the 0 guage LS.

0 - .297
1 - .2982
2 - .2990
3 - .2998

When it is appropriate remove the LS and measure it for size and order the next larger guage in the same size and you will be back in business.

The engineers for FN foresaw this need apparently.

If you needed a 0 guage LS in a .262 size you would obtain a 1 guage in a .262 for a proper replacement.

416Rich · February 10, 2005, 12:03

My century arms l1a1 does the same thing.I checked the headspace and its okay.I think i will try some locktite.

Bruce Allen · February 10, 2005, 19:14

Properly done the LS are a friction fit.

I do not know how well locktite will hold, but I do know a properly fitting LS will never work it's way out.

Court in Fl · February 10, 2005, 20:44

I have come accress a few locking shoulders that where filed on and had a slight taper from one end to the other.
I wounder if this taper could make the locking shoulder move slighty.

Red locktite should fix it good.

Court in FL.

50 cal · February 11, 2005, 11:49

Adhesives probably won't hold in the LS area. To much lube to get in that area and soften the loctite.
Try staking it in if you can't get the correct gauged LS.

Stranger · February 11, 2005, 15:19

Peen it?

critterflht · February 11, 2005, 18:48

Grind a small notch in the front edge of the "foot" of the LS. Re-install in receiver. Using a prick punch and small hammer, stake material from the receiver adjacent to the notch over into the notch you ground into the LS-

This is what I did to mine when I found that oversized pin locking shoulders weren't very plentiful. Haven't had another problem-
Lee

**W.E.G.** · February 11, 2005, 23:22

If you need a custom-sized, fat-shaft locking shoulder, I'm pretty sure Ed Vanden Berg can furnish it.

critterflht · February 12, 2005, 09:28

I checked with Ed when I had my problem, he couldn't help me-
Lee

H. Nipps · February 12, 2005, 18:45

Hope you don't mind if I ask a question on this subject. When I pressed my locking shoulder in using a big vise, I noticed that it still stikes out just a touch . Is this acceptable? Or should I try to get it flush with the receiver? I fired it and it did not move. Should I just leave it. It's not out more than an Millimeter or so.

familyman357 · February 13, 2005, 00:13

H., is it a DSA receiver? They typically leave a little bit of locking shoulder foot protruding. It would be normal for a DSA upper.

H. Nipps · February 14, 2005, 09:14

Familyman357,
No Sir. It's an Imbel gear logo receiver. It appears to be firmly in place. No movement after a couple hundred rounds. But since I built it, I am concerned that I didn't go in far enough.

mtang45 · February 14, 2005, 09:47

My Imbel is the same way, the foot sticks out slightly and is not flush. The other side is flush and I could not drive the LS in any further, so I left it. Been working fine for a very long time.

Ghanziang · February 14, 2005, 14:13

On my IMBEL the LS is sticking out about 1 or 2mm, it has not moved, even after a few 100 rounds. So I am thinking it is doing well and happy.

G.

H. Nipps · February 15, 2005, 09:08

Thanks. I feel better now that I know other Imbel owners have outies too.

February 09, 2005, 20:14	#1
Sumoj275 Registered FALaholic #: 3417 Join Date: Jun 2001 Location: OKLAHOMA Posts: 1,454	Locking shoulder worked its way out a little. Cause and problems? Tonight a friend stoped by with a FAL that he had been shooting today. We were looking it over and I noticed the locking shoulder was sticking out further than where I had seen them on my FALs. Upon a closer look you could see where it had moved out some because it had line from where the paint was and where the shoulder had been. We broke the rifle down and looked for a cracked receiver or anything else that was out of the ordinary but could not see anything. After looking it over he used a plastic mallet head and hammered it in flush with the receiver. Now, I know this is set deeper than it was before because of the paint line. He checked the headspace and it was where he had it originally. Now, if anyone has any ideas why it worked itself out or any experiences like this please let me know so I can relay the message. Thanks from Dave and me

February 09, 2005, 21:35	#2
critterflht Registered Bronze Contributor FALaholic #: 6701 Join Date: Jun 2002 Location: NC Posts: 647	Possibly the LS has been taken out and put back in the rifle a couple (or more) times in the past. Every time the LS is removed or put back in, the fit will get more loose. Or, maybe it didn't fit tightly enough in the receiver to begin with because of a poor machining job on the receiver. Either way, I've never figured out how a LS could work its way out of the receiver at a right angle to the forces applied to it by the bolt, but they can. I had the problem on one of my rifles and I staked it into the receiver. Cured the problem- Lee __________________ Remember, it takes 42 muscles to produce a frown, but only 4 muscles to pull a trigger. The truth ALWAYS offends someone... SHORTEST FAIRY TALE EVER: Once upon a time a guy asked a girl: "Will you marry me?", She said "No", and the guy lived happily ever after.

February 10, 2005, 03:02	#3
Bruce Allen Registered FALaholic #: 186 Join Date: Jul 2000 Location: SC Posts: 4,934	There are 4 different guages of LS, from 0 (zero) to 3. Each is larger in size than the previous, with "0" being .297", if I recall correctly. Most all new receivers are milled to accomodate the 0 guage LS. 0 - .297 1 - .2982 2 - .2990 3 - .2998 When it is appropriate remove the LS and measure it for size and order the next larger guage in the same size and you will be back in business. The engineers for FN foresaw this need apparently. If you needed a 0 guage LS in a .262 size you would obtain a 1 guage in a .262 for a proper replacement. __________________ You cannot post 'Thou Shalt Not Steal,' 'Thou Shalt Not Commit Adultery,' and 'Thou Shall Not Lie' in a building full of lawyers, judges and politicians. It creates a hostile work environment. Last edited by Bruce Allen; February 10, 2005 at 10:18.

February 10, 2005, 12:03	#4
416Rich Registered FALaholic #: 11832 Join Date: Sep 2003 Location: Las Vegas Posts: 194	My century arms l1a1 does the same thing.I checked the headspace and its okay.I think i will try some locktite. __________________ More is More

February 10, 2005, 19:14	#5
Bruce Allen Registered FALaholic #: 186 Join Date: Jul 2000 Location: SC Posts: 4,934	Properly done the LS are a friction fit. I do not know how well locktite will hold, but I do know a properly fitting LS will never work it's way out. __________________ You cannot post 'Thou Shalt Not Steal,' 'Thou Shalt Not Commit Adultery,' and 'Thou Shall Not Lie' in a building full of lawyers, judges and politicians. It creates a hostile work environment.

February 10, 2005, 20:44	#6
Court in Fl Curio & Relic FALaholic #: 5046 Join Date: Dec 2001 Location: South Florida Posts: 3,150	I have come accress a few locking shoulders that where filed on and had a slight taper from one end to the other. I wounder if this taper could make the locking shoulder move slighty. Red locktite should fix it good. Court in FL.

February 11, 2005, 11:49	#7
50 cal Registered FALaholic #: 135 Join Date: Jul 2000 Location: Knoxville, Tn Posts: 515	Adhesives probably won't hold in the LS area. To much lube to get in that area and soften the loctite. Try staking it in if you can't get the correct gauged LS. __________________ 50 BMG, when it absolutely, positively has to be destroyed right now!

February 11, 2005, 15:19	#8
Stranger Registered FALaholic #: 3555 Join Date: Jul 2001 Location: Oklahoma Posts: 9,498	Peen it? __________________ If you are not part of the solution, you are part of the precipitate.

February 11, 2005, 18:48	#9
critterflht Registered Bronze Contributor FALaholic #: 6701 Join Date: Jun 2002 Location: NC Posts: 647	Grind a small notch in the front edge of the "foot" of the LS. Re-install in receiver. Using a prick punch and small hammer, stake material from the receiver adjacent to the notch over into the notch you ground into the LS- This is what I did to mine when I found that oversized pin locking shoulders weren't very plentiful. Haven't had another problem- Lee __________________ Remember, it takes 42 muscles to produce a frown, but only 4 muscles to pull a trigger. The truth ALWAYS offends someone... SHORTEST FAIRY TALE EVER: Once upon a time a guy asked a girl: "Will you marry me?", She said "No", and the guy lived happily ever after.

February 11, 2005, 23:22	#10
W.E.G. Administrator Silver Contributor FALaholic #: 1211 Join Date: Oct 2000 Location: Virginia Posts: 31,055	If you need a custom-sized, fat-shaft locking shoulder, I'm pretty sure Ed Vanden Berg can furnish it. __________________ . . . Ask me about the Mason-Dixon FAL Collectors Association.

February 12, 2005, 09:28	#11
critterflht Registered Bronze Contributor FALaholic #: 6701 Join Date: Jun 2002 Location: NC Posts: 647	I checked with Ed when I had my problem, he couldn't help me- Lee __________________ Remember, it takes 42 muscles to produce a frown, but only 4 muscles to pull a trigger. The truth ALWAYS offends someone... SHORTEST FAIRY TALE EVER: Once upon a time a guy asked a girl: "Will you marry me?", She said "No", and the guy lived happily ever after.

February 12, 2005, 18:45	#12
H. Nipps Registered FALaholic #: 12078 Join Date: Oct 2003 Location: Peoples Republik of Kalifornia Posts: 146	Hope you don't mind if I ask a question on this subject. When I pressed my locking shoulder in using a big vise, I noticed that it still stikes out just a touch . Is this acceptable? Or should I try to get it flush with the receiver? I fired it and it did not move. Should I just leave it. It's not out more than an Millimeter or so.

February 13, 2005, 00:13	#13
familyman357 Registered FALaholic #: 11502 Join Date: Aug 2003 Location: Northwest Ohio Posts: 804	H., is it a DSA receiver? They typically leave a little bit of locking shoulder foot protruding. It would be normal for a DSA upper.

February 14, 2005, 09:14	#14
H. Nipps Registered FALaholic #: 12078 Join Date: Oct 2003 Location: Peoples Republik of Kalifornia Posts: 146	Familyman357, No Sir. It's an Imbel gear logo receiver. It appears to be firmly in place. No movement after a couple hundred rounds. But since I built it, I am concerned that I didn't go in far enough.

February 14, 2005, 09:47	#15
mtang45 Registered FALaholic #: 13104 Join Date: Jan 2004 Location: Kansas City, MO Posts: 1,317	My Imbel is the same way, the foot sticks out slightly and is not flush. The other side is flush and I could not drive the LS in any further, so I left it. Been working fine for a very long time. __________________ "[L]et us solemnly remember the sacrifices of all those who fought so valiantly, on the seas, in the air, and on foreign shores, to preserve our heritage of freedom, and let us re-consecrate ourselves to the task of promoting an enduring peace so that their efforts shall not have been in vain." -Dwight D. Eisenhower It is worth remembering these timeless words John Stuart Mill: "War is an ugly thing, but not the ugliest of things: the decayed and degraded state of moral and patriotic feeling which thinks nothing worth a war, is worse." Lex et Libertas — Semper Vigilo, Paratus, et Fidelis!

February 14, 2005, 14:13	#16
Ghanziang Registered FALaholic #: 11019 Join Date: Jun 2003 Location: The Woodlands, TX Posts: 64	On my IMBEL the LS is sticking out about 1 or 2mm, it has not moved, even after a few 100 rounds. So I am thinking it is doing well and happy. G.

February 15, 2005, 09:08	#17
H. Nipps Registered FALaholic #: 12078 Join Date: Oct 2003 Location: Peoples Republik of Kalifornia Posts: 146	Thanks. I feel better now that I know other Imbel owners have outies too.

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