ALUMINUM RECEIVER BARREL TIMING

[Dwight]

I would like to report a few things that we have encountered since our release of the aluminum receiver. As a starter, we engineered the aluminum receiver in the prospect that virtually all of you could assemble the receiver to an existing kit without the need to do any machining on the barrel to adjust timing. As of today, we have had four (4) people with problems with barrel timing. Our first report of a barrel timing error was first of last week from a customer. We have been working the problem continuously since that time. I have visited with George Gouger at doubleggunsmithing on several occasions over the last week and half trying to come up with a solution. It has become clearly evident that making a receiver to use a STG 58 and a South African barrel is not going to work, without some gunsmithing involved, maybe.

My dilemma at this time is that I would like to have a receiver that you folks who don't have access to a lathe can still assemble a barrel on to our receiver. At this time, I only know of two (2) available options that are worthy of discussion.

1) Manufacture the receiver with the timing adjusted as you would except from a Imbel receiver. Which would typically require turning the shoulder down on the barrel to obtain proper timing and headspace.

2) Include a package of breach washers consisting of three (3) washers, all in .002 thickness. For a total adjustment of .006, which would compensate for the differences between say the South African and the STG 58 barrels.

From a precision machinist prospective, I'm 100% comfortable with recommending the breach washers on the aluminum receivers. Matter of fact, the odds of maintaining the precision of the barrel flange is much greater if you don't have to go back and re-machine the barrel flange, unless of course you send it to George or a qualified gunsmith. I'm also aware that some of you would tend on frown on using breach washers on the metric receiver.

So with that in mind, I would like to hear your opinions of the available options presented. At this time, these are the only two options that I see that is feasible based upon the aluminum receiver design. However, if there is any options that someone might have that has not been mentioned, we are happy to listen.


Dwight E. Williams

[sparky]

Dwight

If the breech washer is the final fix will you send the washers to us that bought in the group buy? Also my ARMS mount will not slide into the rails can that be fixed with out modifying my mount?

[kotengu]

I think the breech washers would be a great compliment to the inch receivers (make it a whole lot easier on us to mate it up right) - I don't suppose you want to include a selection of various sized locking shoulders, too

Matt

- I love the concern of this guy - everybody else I've seen make a product is more than happy to say "oh well" there's too much variation in the mating parts so make it fit on your end. BTW - have you had any issues come up with your inch pattern recievers yet (I'm in the need.....)

[Dwight]

Sparky,

We are prepared to ship breaching washers to those who may run into problems assembling a STG 58 kit, or to replace the receiver at our cost.

As for the ARMS mount, I have three of them, and I've had to modify each of them to fit my own receiver as well as an DSA and Imbel. Please be patient however, we will be introducing a mount that won't need modification!

Dwight

[Dwight]

kotengu:

We manufacture the Locking Shoulders in-house for our own use. Because of the interest in the past couple of weeks, we are considering offering the full range of locking shoulders in the next few weeks to the general public. Cost would be around $8.00 - $10.00 each.

As for the Inch Receiver, we haven't had any feedback as of yet.

[ August 21, 2001: Message edited by: Dwight@www.williamsarms.com ]

[Dirtfarmer]

Dwight,
I think that you will meet little resistance with the breeching washer idea. ---These folks like whatever works, aluminum alloy receivers included. In my opinion, I think it's a great solution.
Goodwill,
-Dirtfarmer

[Andy the Aussie]

Dwight......hey mate....you errrrrr wouldn't like to sent a couple of completed LW Fals into the "deep" south for testing in their "natural" envioroment...

All the best with the business...I am just jealous of all these folks here who CAN have one.

Andy

[ August 21, 2001: Message edited by: Andy the Aussie ]

[sparky]

Dwight

I am using a G1 for my build it will be here in a few days. Does anyone know how a G1 will time will it be the same as a STG? Also what do you think the mount will be priced at? If I modify my ARMS will it still fit my DSA?

[Dwight]

Originally posted by sparky:
Dwight

I am using a G1 for my build it will be here in a few days. Does anyone know how a G1 will time will it be the same as a STG? Also what do you think the mount will be priced at? If I modify my ARMS will it still fit my DSA?

Sparky:

I had to modify the ARMS mount to fit my DSA. After modification it works on all three receivers.

Price on the our mount will be around $50.00

[W.E.G.]

Each option makes good sense.

Seems to me that the choice is more one of aesthetics. Howzabout offering both configurations, and letting the customer choose?

Good to hear that you have .002" washers available. I'm building a FrankenFAL. So, I'll give you a holler if WECSOG 1 times long.

[redneck whitesox PBR]

Personally I would not mind breaching washers
but would prefer not ot use them if at all possible.

[kyle]

Dwight...Since I don't know what kind of barrel I'll be using, it seems the washer idea would offer the most flexibility. That said, I'd really like to hear from George or Mark on this issue. Thanks for sharing this with us!

[reidry]

Dwight,

I shipped my receiver back at the end of last week per your instructions.

Personally I'll accept whatever solution you recommend.

I have access to a lathe and can make the necessary adjustments to the barrel shoulder, however the breeching washers would work as well. Prior to shipping my receiver back I was going to punch out some washers from .001 or .002 shim stock.

Please advise.

[TrooperDan]

Dwight;

I love the idea of including some breeching washers; use 'um if you need to other wise same them for another WECSOG day!

Dan in NC

[falup]

In Falsmith we trust.

[Deltaten]

Mr Williams, et all:

"from a precision machinist's perspective.."
That's all I need to hear. Now add the service, concern, and care (and George's "blessings", no less!) factors, and I'm more than happy to use breeching washers.

Avidly awaiting mini-group purchase arrival. 5 metric and 2 inch, to Village Arms, Gap, PA... any news on shipping date????

Thanks Dwight,
Paul

[chickenlegs]

Dwight I use a lathe on my barrel shoulders, so it no problem to me.But not everyone has one,the breeching washer is a GREAT way to time a barrel.This would keep the barrel shoulder square,a file will not.My hats off to you sir.

[pauld]

I will go with the breaching washers too. I hope to have the cash for an aluminum receiver soon.

Paul

[Enquiring Minds]

1) Besides the fact that no FN contractors used breeching washers on metric FALs, is there any MECHANICAL reason that makes them incompatible with metrics? See none in the FAQs.

2) I would like to understand the mechanical/metallurgical reason that a steel barrel needs so much less torque to mate with an aluminum rcvr than a steel rcvr? Does it have to do with the elasticity and deformation of steel vs. aluminum?

I've read all the Williams threads I could find, without full satisfaction. People talk about the torque required on steel receivers as if it were a design flaw instead of what it is: an engineering spec., not arrived at arbitrarily.

Thanks in advance.

[ August 21, 2001: Message edited by: Enquiring Minds ]

[Zed Stewart]

I have to admit that I am number four on the list of potential returners. I have no problem with the breeching washer fix. My barrel hand tightened at five minutes past 12. This leads me to the only problem I can see with shimming a metric rifle, oversized locking shoulders.

I ran the numbers to see what size locking shoulder it would take to get mine to headspace and it turned out to be .280! I think that that is a little on the large side.

[1006587]

I'm not an expert but I did stay..

Anyway, this is what I know about aluminum and steel. Aluminum is very stiff and will snap when the torque spec is exceeded. There is not much margin of error. Steel is very flexible and much stronger. You can "feel" when you have it about right. There is more margin of error.

My experience with this is automotive. I know that if a torque spec for a bolt in aluminum is 10 ft/lbs, it may not feel like enough but put 12 lbs on it and it will strip, without warning. This doesn't mean that it is a weak joint. The bolt holds perfectly at its design spec. I stripped many threads to learn this.

Back to the receiver. This is a new material for a receiver. What Dwight says about torque makes sense to me.

[TFA303]

Dwight,
Related questions:
1. (posted on an older thread)
Do you recommend using anti-seize compound when barreling one of your receivers?

2. For what barrel is your receiver "designed"? (This from your comment that an STG58 / R1 are not intrinsically compatible.)

(My aluminum experience is limited to aluminum cylinder heads.

Tom

P.S. Thanks for the great responses and strong Web presence!

[Batman]

Dwight, do you recommend using loc-tight on the barrel threads when final timing the barrel? If so which one?

[ramiller]

I don't have a concern on the breech washers, they have proven themselves with the inch pattern fal, but based on the problems with the use of dissimilar metals the washers should have a coating to prevent oxidation due to the porosity of the aluminum with moisture or corrosive liquids.

[R4 fan]

I'm not going to assemble my kit anyway, so I would like to hear from George Gouger on this issue also. After all, I'm going to have him build this kit for me (after the Izzy HB).

[Dwight]

Originally posted by TFA303:
Dwight,
Related questions:
1. (posted on an older thread)
Do you recommend using anti-seize compound when barreling one of your receivers?

2. For what barrel is your receiver "designed"? (This from your comment that an STG58 / R1 are not intrinsically compatible.)

(My aluminum experience is limited to aluminum cylinder heads.

Tom

P.S. Thanks for the great responses and strong Web presence!

Tom:

I myself have used anti-seize compound on assembly. I would however recommend not over doing the amount applied. It doesn't take much to accomplish the task. On the aluminum receiver, it is hard anodized coated, which means that galling is not an issue with assembly as one might think on aluminum thread assembly.

Dwight

[Dwight]

Originally posted by ramiller:
I don't have a concern on the breech washers, they have proven themselves with the inch pattern fal, but based on the problems with the use of dissimilar metals the washers should have a coating to prevent oxidation due to the porosity of the aluminum with moisture or corrosive liquids.

As for the dissimilar metals, the aluminum is hard anodized which completly prevents any possible oxidation.

[Dwight]

Originally posted by Batman:
Dwight, do you recommend using loc-tight on the barrel threads when final timing the barrel? If so which one?

Batman:

I would only recommend the loc-tight if the barrel came up to TDC with very firm hand torque. If you are trying to compensate for a ATDC condition, I wouldn't recommend the loc-tight. The high-strength (RED) loc-tight would be my recommendation in that application.

[Gavin]

A few questions...
is it extra to buy a receiver without the EJ block? I am working on a post sample, and don't need the extra work. Also - once the hard anodizing is removed by milling on the rec. will the underlying Al be strong enough, or will I have to form 5 the rec. to get it re-anodized?
Gavin

[paulp]

I thought anodizing was process that essentially turned the aluminium into a ceramic. I wonder if the resulting ceramic in this case is an insulator. If it is, then there is probably no need to worry about contact between two dissimilar metals causing corosion. What do the chemists and metalurgists have to say?

[Gavin]

PaulP - i am a graduate student in Chemistry - finishing up a PhD (albeit not in metallurgy) - my take is, anodizing is a surface passification technique ie. it pre-reacts sites on teh surface of the metal so that they don't react. Once anodized, Al can no longer react (like once phosphated Fe is harder to oxidize)
Regards
Gavin

[Ken]

The anodizing forms less reactive aluminum coupounds on the surface but, as we all know, when you thread a barrel into the receiver, you remove some of that protective coating, exposing aluminum metal on one side and iron on the other. You will have galvanic action in these areas. I'd use the anti-seize but even that will not prevent galvanic activity.

Metallic aluminum is very reactive in the environment but once it forms an oxide layer, that greatly slows any reaction. Hey, this is why aluminum metal is not generally found in nature.

Also, don't confuse anodizing to produce a nice colored surface with other types of treatment of the metal to strengthen or harden it, such as alloying with other metals, heat treating, etc.

[Sailor553]

Dwight,

Any experience in screwing stainless barrels into your receiver? (that don't sound right?) Of course, the stainless barrel will also be anodized/treated.

[Blag]

Originally posted by Ken:
The anodizing forms less reactive aluminum coupounds on the surface but, as we all know, when you thread a barrel into the receiver, you remove some of that protective coating, exposing aluminum metal on one side and iron on the other. You will have galvanic action in these areas.

Okay, so...... how do we rig a sacrificial anode here? (For people who are curious and have nothing else to do.)


The carry handle would be in the "galvanic pathway," I guess, between the steel barrel and aluminum receiver. Maybe, polish a small spot on the carry handle arm, clamp a little pellet of sacrificial metal there, and see what happens. Would zinc work? I think that's what they use on aluminum outboard motors. (Could be wrong.)

But I doubt this is really a problem, or ARs wouldn't last as long as they do.

[stargazer]

Dwight, We sure appreciate your concern and fast responses! Plan on having a thriving business from now on if you keep this up!!!

Did I read an "arms" type scope mount is in the works? Any pixs available, material used, etc. Priced around $50? Consider one sold!

Breaching washers sounds like a very good idea for this situation. Why not also send exact instructions with each reciver along with the washers.

Thanks again for all your input and help to us FalFiles members!

[overdriv]

Dwight, I would think you would want your receivers to be as well received in the entire gun community as the Imbel is. Although my experience is not as diverse as some, the STG58 kits that I have assembled and helped assemble all timed from 10 -10:30 on the Imbel receiver. It would seem to me that any receiver which timed ATDC would be defective.

With that said, I'm quite sure one could use a breaching washer/shim, whatever, to achieve the proper timing/torque. That is a normal procedure on an inch gun as I understand, but not on the metric.

I think I would not be interested in a metric receiver that would require a breaching washer or shim to achive proper barrel timing/torque. To me, it sounds like a cheap fix for a mistake.

I think there are enough folks out there that this will not make a bit of difference too. You will probably sell them all, but do you really want to do it that way? As particular as you sound in your posts, I just can't see you advocating shimming the barrels on your metric receivers. Unless you are looking at it from a strictly business/money point of view, in this case, I understand but do not agree.

I have ordered an inch receiver from you, I sure hope there are no similar surprises with the inch version.

Thank you for being so forthcoming here on the FALfiles.

[armedpeasant]

I'm considering building an Imbel kit onto a Williams metric aluminum receiver. Does anyone forsee any problems with getting the barrel timed and headspaced correctly? Is it possible that the fact that barrels thread into these receivers without much torque could actually be a benefit to someone like myself who would like to try to build a kit using run-of-the-mill tools, instead of spending money on barrel blocks, a receiver wrench, and an expensive vice? I apologize, in advance, if that last question was stupid.