barrel installation - IMEBEL receiver - tight threads - won't go all the way

[NEWGUY]

Picked up 2 Imbels today to go with my R1 kits. I was messing around tonight and put them together to see what a finished rifle would look like. (Okay, I was playing with my new toys... http://www.fnfal.com/forums/biggrin.gif )

Anyway, the barrels thread in part way and then get rather tight. I've tried both combinations and it's all the same. Is it normal to be pretty tight? That's why there's a wrench, correct? This is my first project so I was just wondering if the threads could possibly be different when the rifles come from different companies.

Thanks!
ps - boy am I happy!!!!! http://www.fnfal.com/forums/biggrin.gif http://www.fnfal.com/forums/biggrin.gif http://www.fnfal.com/forums/biggrin.gif

[ August 05, 2001: Message edited by: gary.jeter ]

[ August 26, 2001: Message edited by: gary.jeter ]

[Wadman]

I think there's plenty of material in the FAQ section on barrel assembly and timing it with the receiver. Hand threading should get you to 10-11 o'clock until it stops. The most common thing I've read is that 100 to 150 lb/ft of torque is required to get it to top-dead-center. Someone else recently posted a picture of what his hand threaded barrel-receiver looked like.

[NEWGUY]

Thanks for your reply but I couldn't find anything to address my question there. My problem (if I have one) isn't timing, it's that I can't thread the barrel on by hand after a couple turns.

The barrel will stop leaving 1/4 - 1/2" of threads between the receiver and the end of the barrel threads.

After I can't twist it anymore, I take the barrel off and the threads on both look fine, like they match but something is just a little tight. Should I chase the receiver threads with a tap (too much parkerizing?)?? Like I said the barrel isn't scratching the threads so I'm not sure exactly what's up. Just trying to be careful.

[Wadman]

Ouch! Sorry. I thought you meant it was tight but flush with the receiver. Some threads still showing, huh? Actually, it sounds like you've got a lot of thread showing. Everything I've read says to either make a wrench or use an adjustable and make sure it's tight on the barrel flats. You don't want it slipping and rounding the flats. Then try and turn it the rest of the way.

If the threads look okay but you find that you still need a lot of force with a wrench(subjective, I know so use your best judgement), back off the whole thing and ask one of the 4 or 5 gunsmiths on the board for more help.

================================================== =========

Imbels are usually metric. But aren't R1 kits also metric? My project was a metric Imbel receiver with an STG barrel. It hand threaded till flush with the receiver. Can you tell if the barrel has tapered threads or something? Maybe the S. Africans were really goofy and wanted extra tight barrel/receivers.

[This message has been edited by Wadman (edited November 30, 2000).]

[NEWGUY]

Thanks Wadman.

I figured you misunderstood. Now I have the answer I was looking for - at least one person says this isn't normal. I won't force anything till somebody with R1 experience comments. Appreciate the help....wish mine threaded all the way http://www.fnfal.com/forums/frown.gif

[Fred]

In most cases the threads have left over burnt oil and threadlocker left in them. This debris causes the threads to bind, keeping the barrel from seating fully. As a rule I chase the threads and then the barrels always go on smoothly. As I have a die this is easy. However, not all is lost. Some patience with a sharp knife will clean out the threads.

[NEWGUY]

Thanks for the tip. I cleaned the threads as much as I could (with a small screwdriver) without going insane. They seem very clean and free of gunk.

The receiver threads (obviously) look brand new and have nothing wrong with them. The parkerizing doesn't look too heavy and when the barrel is screwed in it doesn't scrape anything off.

The cleaning of the threads on the barrel didn't help me out. Could this be a slight difference in the height of the threads themselves?

What's the size of the die you've used? Hopefully this is the problem. I guess if nothing else I could run a stone of very fine file over the tops of the threads to give me a little room, but I'd rather continue to chase them and make sure that's not the problem first.

[W.E.G.]

I can't imagine that there is a discrepancy with the threads. Assuming that your barrels came off real metric FAL rifles, and the receivers are metric, the barrels have to go on.

What I suspect is there may be some slight stacking of tolerances between the parts and the coatings so as to cause enough binding to prevent hand-tightening.

You just aren't using enough wrench my friend. You do have the proper wrench don't you? If you don't have the right wrench, you better get one before you mess with it any more.

Support the receiver in your vise with the bolt carrier in place to prevent squashing your receiver. Apply anti-sieze compound to the threads and screw the barrel in. Don't tourque the shoulder down. Repeat the process a few times to relieve as much stress on the threads as you feel is necessary. Disassemble, and clean the a/s compound from the parts.

You can go the route of taps and dies to smooth the route. But, I think it is unnecessary. The thread size is 1" diameter, 16 TPI.

If you somehow got inch-pattern barrels, you must use a die ON THE BARREL ONLY to correct the slightly different thread pitch found on inch barrels.

According to the Gunplumber:
"The Term "Inch Pattern" refers to the L1A1. That is Australian, British, Canadian, and Indian (although Indian parts may vary slightly). The term "Inch Pattern" however is a bit misleading when compared to metric, because both Inch and Metric guns are built to the English thread pitch and are mostly interchangeable with metric. It is more a general term for the system of the country of origin, and perhaps "Commonwealth Pattern" and "Belgium Pattern" would be more accurate. Israeli is different only in the barrel thread, and front sight thread. Some Argentine guns also use the non-standard Israeli front-sight thread pitch."

[NEWGUY]

Um, did I mention I'm not using any wrench, just hand tightening? I felt pretty sure that the thing should go on part way with hand pressure. Maybe I'm wrong. HOPEFULLY I'm just being ignorant again. http://www.fnfal.com/forums/biggrin.gif

I am not trying to assemble the guns yet, just screwing around (sorry about the pun). I was just going to screw a barrel in to see how heavy the finished rifle would be, and to play with it in the living room. The thing didn't go on very far so I figured I should ask now since I just bought the receivers and could take them back if something was wrong.

A friend from the forum is about an hour away. He's offered to help me build a kit so we'll see how it turns out. Usually when somebody who knows what they're doing is involved things work out much better. hehe

[gman]

That sounds almost like an Israeli barrel.

[Doubleagle]

Originally posted by NEWGUY:
Picked up 2 Imbels today to go with my R1 kits. I was messing around tonight and put them together to see what a finished rifle would look like. (Okay, I was playing with my new toys... http://www.fnfal.com/forums/biggrin.gif )

Anyway, the barrels thread in part way and then get rather tight. I've tried both combinations and it's all the same. Is it normal to be pretty tight? That's why there's a wrench, correct? This is my first project so I was just wondering if the threads could possibly be different when the rifles come from different companies.

Thanks!
ps - boy am I happy!!!!! http://www.fnfal.com/forums/biggrin.gif http://www.fnfal.com/forums/biggrin.gif http://www.fnfal.com/forums/biggrin.gif

I had the same deal-Imbels and R1 kits- and am as iggernant as any new guy. Hand tightening while playing with the new toy went badly and tried to find a die to chase the threads. Only one I found was in a catalog for $25 OR MORE. Then I remembered there is such a thing as a thread file!!! I borrowed one but I'm sure the cost is less and it has other thread sizes so it can be useful on other projects as well. Just be sure to get the right size (16TPI for the barrel threads) and scrub hard. Worked for me! Now as soon as Casey sends my receiver wrench I can move on to the next plane of existance


------------------
NRA LIFE MEMBER
USAF RET

[NEWGUY]

Uh oh........

I guess I didn't try all the combinations because today I got one of the barrels to screw the whole way on to the receiver. Now I have one kit that seems fine and one that won't screw on like it should.

Do you guys think I should call Harlan and see if he'll trade the barrel?

[W.E.G.]

Hey NEWGUY!

Tell us how the story ends!

Did you get that second receiver and/or barrel to work?

[zoom]

At work, we used to use brake cleaner then starting fluid (ether) to remove the old anti-seize compound and loctite. It did make the bolts easier to screw back in.

[Radio]

This was one of those situations where you really wish you could look over the guy's shoulder and SEE the problem. Could his threads actually been that crappy? Or was the barrel cocked a little and he was in danger of cross-threading if he forced it? One thing I learned early, DON'T FORCE PARTS TOGETHER THAT DON'T WANT TO GO TOGETHER. "Ask me how I know."

We may never know, this dude may be dead or have moved to Mars by now.

--Radio :(

[Abominog]

I've had barrels, particularly R1, that don't screw in without A LITTLE help from the wrench.

Just use the wrench gently- you can usually tell if you're cross threading. Go slowly- a turn or so. Back the barrel out. Check the reciever- any cross threading? If not, then you're OK.

[gunnut1]

I had the same problem with my Imbel kit going onto an Imbel receiver. It was nothing that a barrel vise and receiver wrench didn't take care of.Just make sure that the threads are clean. A wire wheel will make short work of this.

Thanks for helping me build my kit there Randy!

[Offctr]

Second that I had to use a wrench with the rcvr supported in the vise to get the barrel (Imbel On Imbel) to thread in all the way (not tighten)or just spin it down to where it started to lock up on the shoulder --it was not tight the whole way just needed a little extra leverage --and to clean the threads out somewhat --after that the barrel would spin down by hand. Stiil had to do some shoulder relieving to get the barrel to time up right . Good luck !

[kotengu]

What Ofctr said - I had an STG barrel on an Imbel do that to me. It was my first, I was excited, and I just torqued the sucker down. I still had to relieve some of the shoulder to get it to time. Maybe if I would have cleaned it more thoroughly first it would have gone on more easily - oh well, it's on now ;)