View Full Version : Entreprise Receiver Locking Lug Problem

April 03, 2002, 23:06
What, if anything, can be done to correct the failure of an Entreprise receiver to lock tightly to the lower (tried two different lowers - both had 1/32" gap between upper and lower). The uppper's locking lug is cut to thin, and the lowers latch is all the way forward when engaged.

Other than building up the latch's surface surface by a sixteenth of an inch or so, what method may be used to correct this problem. Thanks.

April 03, 2002, 23:31
I'm guessing you'll be sending this particular receiver back to Entreprise. Better contact their customer service department.

Do you have any other FAL receivers you can take measurements from for the sake of comparison?

April 04, 2002, 09:50
I have Imbels which I have compared visually but not with calilpers or mic. The lug is noticeably thinner (the latching "slot" is noticeably wider) than the Imbels. I'm not sending it back to Entreprise as it is already assembled, plus I picked through eleven Entreprise Type 3's to get this. I guess I'll just "fatten up" the surface of the latch piece with a welder and file to fit. Any others ideas out there on this?

April 04, 2002, 10:04
Have you tried adjusting the nose of the locking body? You could build up the nose of the lug, and then trim to fit. Cheap and realtively easy solution.

This is a new wrinkle. I have two excellent Entreprise receivers, and neither exhibits this problem. It is alos possible your original locking latch is worn, and needs replacement anyway. try Tapco for NIW replacements.

What 'donor' kit are you using?

April 04, 2002, 10:45
The kit is a R1/STG from Federal from year or so back. The latch isn't worn appreciably on that kit or the STG lower from another kit that is currently on the upper now. The receiver locking area is "over cut" (too wide of a notch) so that the latch bottoms out without a tight lockup (lever all the way forward on the lower). Building up the nose of the latch is what I will do to correct the problem.

This is my only experience with Entreprise (a group buy). After picking this one out of a batch of eleven receivers, I saw first hand the very large problem that Entreprise is having with their QC. I'm happy with the receiver in spite of a few fitting problems, but it really is a hit and miss proposition with Entreprise. If they could only get their QC under control, their more varied product line would be very attractive. As a former QC engineer, I KNOW that an effective QC system is the lowest cost option. I'd like to buy an Entreprise inch receiver, but QC is too big a problem at this point.

April 04, 2002, 10:51
Write Lawrence.

Meanwhile, I still think building up the lug face will solve the problem easily.

I quite agree: in nuclear, it's much easier to build the QC in on the front end. Post-assembly inspections only prove whether you got it right or wrong.

PS- it's R1 or StG: the Austrians didn't supply South Africa any StG kits AFAIK. It might be an FN-built R1, or an ArmsCor/Lyttleton R1 though.

[ April 04, 2002: Message edited by: EMDII ]

April 04, 2002, 10:57
The reference was to the mixed R1/STG kit that Federal was selling a while back.

April 04, 2002, 11:14

I am out of touch. A REAL Franken-FAL donor! There's switch!

The buildup idea is relatively simple, and allows you to tune the lug anyway. reverse of trimming face off for overly tight receiver lock up.

Let us know what you do.

April 04, 2002, 21:30
rwwje, I mainly play with L1's, but most of this should still apply. I've been lurking here for awhile and this appears to be one of the most misunderstood of all topics. There is much, much more to the locking body/catch then most people realize, This was an anticipated condition in the FAL's, regardless of receiver mfg., hence the assortment of component sizes originally available.

Aussie and Brit L1A1 locking bodies/catches

1. First, there is 3 different sizes of original locking catches:
a) "std"
b) "1" (IIRC it's std + .003")
c) "2" (again, IIRC its std. + .006")
The oversized catch will have the number etched on it using 1/8" characters.

2. Make sure that there is a minimum of .010" (.003" field) between the lever and the rear face of the "sheild" block housing (take up free movement before measuring), if this clearence is less then .010" exchange the catch and/or the locking lever. Of course make sure that the lever is not bent or distorted. The operating pin must also be square (90 degrees) with the lever and parallel to the axis pin.

3. There is a difference in aussie and brit catches which can also cause problems, the aussie is missing one .030" long,45 degree chamfer that the british catch has, this missing chamfer can cause the catch not to engage properly on some non-aussie receivers.

4. Of course you want to make sure that the rear of the body and cover are not bearing heavily against the front face of the shield housing.

5. Make sure that the locking catch retaining pin is not distorted and causing the locking catch to bind in its housing, and bear incorrectly on the body lug.

6. Make sure the angle of the front lug is machine to 9 degrees 15 minutes, The top angle of the catch should be 35 degrees +/- 30 mins, the engaement face angle should be 10 degrees,

7. The engagement face angle can be adjusted so that the catch engages the body by .060", the catch must also bear evenly for its full width, verify with dykem blue or some other suitable means.

I know there is something Im forgetting..., but that is the majority of it.


April 04, 2002, 22:46
That pretty much covers E&MER Issue 9, but I can add, if welding up the lug, which I have to do frequently on entreprise receivers due to the poor quality, is to first grind it down .005" for a width of .190". Then build up with .015" of weld. Standards in E&MER #7 state to use microflow powder "bronze chrome" 10185 Hardness DPH 360-440 nickel based alloy overlay for steel. The grinding will give beter penetration. Then surface at 10'30" to 125 micro inches. There should be no step.

April 04, 2002, 23:42
Gunplumber, It's common knowledge that there is a conflict between you and Entreprise, thats fine, I dont want anything to do with it. I posted info I thought was appropriate, factual, hopefully helpful and without bias.

However, now I feel I have to ad something further, in the reference you quoted you failed to mention the very first line which may put it in a totally different light, and I quote:

"All rifles undergoing Base overhaul/repair are to have the body lug rebuilt to plan size using the following eqiupment and store:"

Not some rifles...but all rifles, now is the problem in rwwje's reciever.... I dont know, I've not inspected it personally, he asked for help so I posted the info "I" thought he needed to make a proper determination.


[ April 04, 2002: Message edited by: BriarJumper ]

April 05, 2002, 10:29

Your post was very informative and I learned a great deal from it.

However, think about this:

How much overhaul and/or repair should a BRAND NEW receiver require? Especially one that advertises "trouble free assembly, torque barrel, headspace, and shoot" :confused:

I am under the impression that overhaul or repair means to bring used and worn parts back to serviceable.


April 05, 2002, 21:24
Exactly why I didnt make any judgements, but the only entreprise group buy im aware of was in Nov./Dec. 2001.

It could very well be the receiver, again, I have personally not seen it, so I dont see how anyone who hasnt seen it can make such a judgement, but maybe im missing something, if so my apologies,

Again, I didnt say his receiver wasnt at fault, nor did I state it was at fault. I posted the proper troubleshooting procedures and thats all

The welding of the locking lug was manditory on any rifle brought in for base repairs, regardless of the nature of those repairs. In the field the procedure was the oversized catches. Again, this was not only an anticipated problem, but one that was so common that it became a manditory repair at the base level, and also required the availibility of oversized catches for unit level repairs

Is the receiver at fault in this case, I dont know....BUT doesn't rwwje NOW have the info he needs to make the proper call?


[ April 05, 2002: Message edited by: BriarJumper ]

April 05, 2002, 21:26
I don't understand your comment. I simply elaborated on your excellent post. The fact that entre'prise new receivers are frequently of such quality that the lug needs rebuilding to print before even fitting to a rifle, has no bearing on the METHOD you described and I elaborated, on for doing so. Also, I guess its subject to interpretation, but I read it as meaning THOSE THAT DON'T meet print, are rebuilt as such. If a rifle is sent to base overhaul because of a bent barrel on a new receiver, reprinting the receiver seems a waste. Gauging it of course is expected.

April 05, 2002, 21:44
Because of the past history of this board and you vs. entreprise I took your post to mean that only entreprise receivers ever needed this repair, and that is not true. I went out of my way to only state fact, not opinion, If I took your post in the wrong light, my apologies sir.


April 05, 2002, 23:48
....BUT doesn't rwwje NOW have the info he needs to make the proper call?

Yes you provided some info. Very helpful and knowledgeable too. Both GP & I have commended you for it.

I wanted to provide some as well. I merely quoted directly from the Entreprise web site, with a little reflection added to stimulate thought.

Not to rub dirt in rwwje's wound's, so to speak, but to inform future builders. If the owner of this particular receiver was not skilled enough to weld it (or repair it otherwise) don't you think the cost of having it done would exceed the $ saved by buying it over a DSA or Imbel in the first place.

Remember the old Fram Oil Filter commercial, "you can pay me now... or you can pay me later." :cool:


April 06, 2002, 01:26
Entreprise receivers are not the only receivers that have needed this repair when new. I have also experienced Hesse receivers with this flaw. I have never seen a new Imbel or DSA receiver requiring this repair. A good way for entreprise to avoid seeing my remarks on how to fix their poor quality would be for them to stop selling receivers that exhibit these defects.

[ April 06, 2002: Message edited by: gunplumber ]

April 06, 2002, 13:23
rwwje ;
I doubt very much that all of your locking pins are that far out of spec.
Best advise for your situation, would be, To have the receiver lug welded up and ground/shaped to spec. If you would have cought it soon enough and sent the receiver back to EAI, more than likely this method would be used. Or you can call EAI and make arrangements for them to repair it.. EAI does have an overall great record for customer satisfaction. Based purely on the numerous post of people that had to resort to actually useing it.

Now GP vs EAI :

Over the past couple of years, I have seen GP virtualy stand alone and take countless bashing`s for his position concerning EAI receivers. It has always ended up just being a GP vs. EAI war of bad blood..And GP`s reveiw and negative comments are unfounded..

Frankly, I`m a little disgusted with this whole thing. As a professional FAL builder myself, I will support GP`s finding all of the way. ( Not because we are buddy, buddy with each other )I have experienced every defect posted in GP`s reveiw and If I dugg deep enough into my past customer`s building note`s I could come up, with close to a dozen other areas that have been functionaly defective , ranging from the front to the back. And never had even two in a row that have exibited the same common defects. CGW will no longer except EAI receivers due to these QC issues. In my view, the problem is the QC of the product and NOT the willingness of the company to support it.

April 06, 2002, 13:46
I'm sitting here looking at a frame lock (the plunger which engages the lug on an upper receiver) and as a toolmaker, I can say that it would be a very straight forward little widget to fabricate. Custom tool work is expensive,.. and I would guess that somebody would have to pay about $35 to have one made, but before I started welding and grinding on an upper receiver, I'd go that route. You could have one made any length necessary.

Of course, you could TIG weld up the surface of the frame lock that you have, and then regrind it, but unless you have access to a surface grinder, you're going to have to do some pretty fancy handwork to get an even surface.

Somebody who was so inclined and had access to some machine tools could probably make some money by offering oversize frame locks,.. they could be offered in +.010, +.020, and so on,.. much like the situation which exists with locking shoulders. I'm surprised that somebody hasn't already done so.

April 06, 2002, 22:38
BriarJumper, I've got to agree with Gunplumber. I've built kits on 2 Imbel and one Enterprise recvr, and the Enterprise is the only one that required any hand-fitting of parts. Especially the locking shoulder hole and recess depth. Also the Enterprise is the only build whereI had to shave some off the barrel to get it to time correctly. The two Imbels were flawless.

April 06, 2002, 23:12
Thanks to all for your help. And thanks to all for the respect shown to each other in what might otherwise possibly become a flame war. Gunplumber has always been right about everthing I have seen him post, including Entreprise's QC roulette. I bought this my first Entreprise with "eyes wide open" on the QC issues (the lug was not its only issue - bolt hold open had a "nodule" near the midpoint to remove, gas tube nut threads at the front of the receiver had to be "filed" to correct threading lead to allow acceptance of the plug). Being a member of the "modify the cheap part first club", I'll be building up the latch initially to see if I can correct the problem - it won't take much - an oversized latch would probably do the job after I mangle, er... buildup, the lightly worn original.

I did put 80 rounds of port (at a gas setting of 4.5, a setting of 5.0 gently laid ten empties on the bench without failure)through the assembled rifle on Friday with six inch, twenty round groups at 100 yards from the bench. That's about the best my way out of date varibale focus prescription can do with open sites with any rifle - the front site is just a fuzzy projection - thank goodness for rear peep sites). ;)

April 07, 2002, 16:15
quote: Rich@CGW

And never had even two in a row that have exibited the same common defects.
__________________________________________________ ___________________

Thanks for the confermation.

April 07, 2002, 21:35
Ditto to what Rich at GCW said. I just finished 2 type I E's and both took a lot of work in totally different areas. I may try one more build with a different reciever. But if these are this much work, I will not build any more.

April 08, 2002, 09:51
I just had the exact same locking lug issue on one of the Entreprise receivers I bought in the Group purchase. There was plenty of movement between the upper and lower, so much so that the charging handle would hit the leading edge of the lower and not fully retract.

I have sent it back to Entreprise and they stated they would replace it with an in-spec one. I should hopefully get it back soon.

April 08, 2002, 10:32
The one I referenced here is also doing the same thing. :mad:

April 08, 2002, 20:30
quote: AaronK

There was plenty of movement between the upper and lower, so much so that the charging handle would hit the leading edge of the lower and not fully retract.

__________________________________________________ _________________________________________

I had the same problem with my type 1 G1 build. Lawrence said he would replace with one inspec before I returned it. After they received it they called and blamed my lower that they said they repaired and was going to send the same POS to me. I refused to be happy with the fix and told them to keep it. The magwell was way to low and that put the feed ramps low also.

April 08, 2002, 22:20
When will Entreprise EVER accept the proposition that there is NO SUBSTITUTE for quality? If they don't, as I've posted before, Dan Coonan (and even Century) is going to kick their ass, take their market share, and leave them in the dust with Hesse. "Customer Service" ain't no substitute for quality - no manufacturer of any product can stay alive in today's market with that business model. Earth to Entreprise: check out, read, implement Demming's QC bible while you still can (if its not already too late). :rolleyes:

April 09, 2002, 13:26
Originally posted by sparky:

I had the same problem with my type 1 G1 build. Lawrence said he would replace with one inspec before I returned it. After they received it they called and blamed my lower that they said they repaired and was going to send the same POS to me. I refused to be happy with the fix and told them to keep it. The magwell was way to low and that put the feed ramps low also.

Yes they originally suspected my lower as well, but I had tried it on a second lower with the same result and told them so. In addition, my friend who was helping me with the build measured it and he found it wasn't sized the same as the other receiver and was ouit of spec.

I'll let people know what I get when I receive it back from Entreprise.

April 10, 2002, 08:09
rwwje, check your e-mail

April 10, 2002, 22:00
HD99FXR3, no mail at home; is there mail at office?

April 11, 2002, 07:12
roger that.