barrel installation ( torque crush shoulder pounds tight )

[Nwfal]

I have read on this board that quite a few recievers need to be relieved in certain areas. Mostly the barrel shoulder. i have done 2 imbels and 1 entreprise and i never had this problem. I use a reciever wrench and a cheater bar and they have presented no problems.Could it be that the 1 1/16 open wrench method is the problem? The lack of avalible torque to crush the barrel face a little bit to get it in the final position? just courious. Thanks

[ September 10, 2001: Message edited by: gary.jeter ]

[TideWater 41009]

Nwfal; I quietly groan every time I read a post about a builder who automatically assumes he has to (or is directed to by some well-meaning individual) to start filing away at the barrel shoulder in order to get the barrel and receiver to time correctly. If you use a barrel vise (not a modified open end wrench) and a receiver wrench (not just clamp down on the receiver in a padded bench vise), and follow the directions given, you should very rarely, if ever, need to relieve a barrel shoulder when using an in-spec receiver.

You can buy a barrel vise and receiver wrench from various sources, or you can make your own using the free plans shown on the GunThings.com web site.

Refinishing Guy.

[Uncle Buck]

I have never seen a StG barrel that needed any cutting on the torque surface to time properly in an Imbel receiver. All this filing seems to come about from having an inadequate tool.

[Aif-work]

I just assembled my Entre'prise Receiver & STG-58 kit 2 weeks ago using a vice and a 1 1/16th wrench. NO PROBLEMS! nothing went wrong everything timed/indexed perfectly. No binding or sloppiness on internals, NO warping. http://www.fnfal.com/forums/biggrin.gif
Needless to say I'm a happy camper after assembling my FIRST FAL!

Aif

------------------
I don't suffer from INSANITY,,,
I ENJOY IT!

[WJ-Polish Guy]

Originally posted by RefinishGuy/GunThings.com:
Nwfal; I quietly groan every time I read a post about a builder who automatically assumes he has to (or is directed to by some well-meaning individual) to start filing away at the barrel shoulder in order to get the barrel and receiver to time correctly. If you use a barrel vise (not a modified open end wrench) and a receiver wrench (not just clamp down on the receiver in a padded bench vise), and follow the directions given, you should very rarely, if ever, need to relieve a barrel shoulder when using an in-spec receiver.

You can buy a barrel vise and receiver wrench from various sources, or you can make your own using the free plans shown on the GunThings.com web site.

Refinishing Guy.

Welcome Refinish Guy! ... I guess you must be Brazilian.... If I remember correctly Brazilians used to overtorqe barrels with some hydraulic monsters and now some smiths do not want replace barrels on those FALs or charge extra to turn/relive barrels...

[Nwfal]

Gentleamn,

I did not not say that the 1 1/16 wrench method is wrong . you can do it whichever way you like. I am just stating the proper way is with a reciver wrench. M1 and M98 are put together that way. I think the problem is more with out of spec recievers then anything else. I use a 3/4 inch torque wrench for the final part of timing to make sure it is torqued correctly. There is no need to be smart a** about others opinion. This type of remarks have ruined many a internet board. Thanks and have a great day.

[Brad/ GunThings.com]

The original Australian L1A1 technical manual we sell states "...the required assembly torque limits of 120 to 181 lbs...." In other words, it's very tight.
Gunplumber mentions 10:30 - 11:00. To backup Uncle Buck, Stg barrels (an obviously high quality barrel) and Imbels (an obviously high quality receiver) usually time at 10:30 - 11:00. Coincidence? I think not. Keyword above is "in-spec". The better the parts are, the less jacking around.




[This message has been edited by Brad/ GunThings.com (edited February 20, 2001).]

[jgs]

Agree with Brad that most of the Steyr/Imbel combos I've seen come out just about right. But for those that don't, has anyone considered following, not the factory crank-em-out method, but the custom bolt-rifle gunsmith method of 'lapping' in the fit? This makes the barrel shoulder/ receiver face a perfect fit AND reduces unnecessary strains and stresses on the barrel and receiver that are not conducive to accuracy - especially when heated up during a long string. A lot more time and work - meaning you probably wouldn't want to pay for a 'smiths time to do this - but if you're building your own at home....Maybe this is too much for just a beater/shooter but if you're gonna put a $100 mount and an umpty-dollar scope on one and want to squeeze ALL the potential accuracy out of it, this seems like an idea that might have merit. I'm going to try it on my next kit (already ordered!) if the fit isn't perfect.... Anybody else done it this way? Competition shooters?

[juanni]

The right tools defiantly make the job easier. I built a receiver wrench that looks like a Brownells model on steroids. It instills fear in most receivers and my lower back. However, I do not think barrels have to be torqued that high. My concern is getting uneven contact between the receiver face and a filed barrel shoulder. Blueprinted bolt action receivers are trued on a lathe in relation to their boltway axis across the face, lugs, internal barrel threads etc. I doubt this treatment on a Fal without a lot of other improvements in the barrel, sights, bolt/carrier slop, and ignition system would produce any significant gain in accuracy. I have checked the face of the receiver for squareness on a couple of Imbels and found no cause for my concern.

[Ape]

An approx. 15 deg final rotational draw was standard when assembling a M-14 battle rifle.
If your fal barrel hand tightens before the accepted notch to triangle position, it looks like about a 30 deg final draw and would probably take well over a 100 ftlbs to align. The two barrels I have installed on new Imbels have hand tightened to this position. At what point do you start to stretch/fatigue/gall threads? Even starting at the previously described accepted position the angle appears to be around 20 deg. Am I missing something or does this rifle require more draw/torque?

[This message has been edited by Ape (edited February 20, 2001).]

[Wadman]

So far, my experiences with barrelling two receivers has run contrary to most of the reponses on this thread. Two Steyr barrels on two Imbel receivers have both timed well short of the prescribed 11:00 (or even 10:30). Both barrels hand tightened to 9:30 or 10:00 and required material off the barrel shoulder. In fact, I got a lot of helpful advice on this board for fixing this problem.

For the last project, I did notice three high spots on the shoulder matching the two wrench flats and the gas tube relief cut. Filing those down helped a lot. But what you're all now suggesting is that rather than removing material, I simply needed a whole lot more force?

[This message has been edited by Wadman (edited February 20, 2001).]

[WJ-Polish Guy]

My personal expirience with imbels and STG barrels is the same as Wadmans. Same is colective expirience on this board....... Thing to remember, If you are shooter sooner or latter you have to change barrel, what then? Torqe needed to unscrew barrel gonna inrease with years compare to one you apply today.

[TideWater 41009]

Hey Polish Guy; I can not begin to recall how many military receiver stubs we have removed from FAL barrels using the original receiver wrench and barrel vise that we made a few years ago. Some of these stubs had been on for 40 years or more. AFAIK, no heat was ever required, and some of these barrels were really cranked in at the factory (certainly more than 200 ft lbs), yet all of them came off with little or no trouble. We have never had to "turn/relieve" a barrel.

"Tighten the barrel to 100 ft lbs" is constantly advised as being "to spec", but it is not. I offer no opinion as to whether this is OK or not, but it is unquestionably looser than how it is done at any factory.

If your particular barrel screwed into your particular receiver will not make TDC with 180 ft lbs or less, then you do need to relieve the barrel shoulder. My point is that this is not a common occurance, and that far too many people have been unwisely encouraged to remove too much metal from far too many barrel shoulders. Period.

If an open end wrench and a padded bench vise will allow you to get yor barrel to TDC with over 120 ft lbs of torque, and without warping the receiver; that's great.

Ape; the exact hand-tighten angle (15 degrees, 10:30-11:00 O'clock, etc.) is a guide to help get the final torque correct at TDC. I don't know what that figure is for an M14, but I would imagine that it is within the ball park of FAL requirements.

Hope this helps,
Refinishing Guy.
(Recent immigrant from Brazil, where I made my living operating a hydraulic monster!)

[Nwfal]

THe first one i did I made a mistake by not putting on the handguard ring. I had it all installed. I just put the reciever wrench back on and took it right off again. No problem at all. When I took my sTg stub off I did the same thing and it came right off.Spend the 60 bucks and get the reciever wrench, you won't regret it,it's one of the best tool investments i have made.

[Jarhead]

Nwfal, where did you get a receiver wrench for $60?

[Nwfal]

Got mine at DSA. When you use it just make sure it's tight and that you protect the finish underneath. I use duct tape and wrap a few layer around the front of the reciever. I learn this the hard way and had to send my first fal to be reparked. Bye

[BBBBill]

Couple points.
1) They DO get tighter with age/use due to gas/carbon fouling leaking into the threads from the breach, so it probably will be tougher to get an older installation off.
2) Most folk don't use a torque wrench to install & don't have a clue how much force/torque they are applying. 18" breaker bar with a cheater giving an effective length of 4' with a 200# ape hanging off the end is 800#s torque. Extreme you say. Trust me, it's happened. Of course that is an exageration, but I'll bet you some have come close. Not just on FALs.

As APE said, what about galling, cold flow, stress cracks, etc?
Use the right tools, whether you make them, buy them, or borrow them. And THINK before you jump. I'd be rich if I had a dime for every time I jumped first.
Of 20+ FALS I've built, 14 were relieved at the shoulder for proper pre torque/clocking. 4 were relieved to true the shoulder from dings/high spots. Home made breaching washers were used on these 4. Only 3 or 4 clocked up correctly as received. All were torqued to about 150#s.
Of course this is my experience & I claim no expert status. Most of my experience is 30+ years of building & tuning 1911s and S&W revos with a few bolt guns thrown in. The bulk of that as a hobby so as they say "YMMV."
Regards, BBBBill

[This message has been edited by BBBBill (edited February 23, 2001).]

[W.E.G.]

moved to FAQ