Receiver Manufacturer Methods

[zinj]

There always seems to be a debate floating around about forged versus cast receivers. However, it seems like there is a lot of over-simplification and ambiguity in this debate. For example, as gunplumber stated in a thread in the M14 section:

Originally posted by gunplumber


Side note, DSA receivers are not forged. They are machined from a block of steel. Even if that block was formed by hammers instead of rollers, it is not a "forged receiver".

As such, I think it would be worthwhile to list what methods were used by each of the manufacturers. I am not even close to knowledgeable on the topic, but here is my understanding:


OEM

FN
Type I and II were machined from forgings, Type III were cast.

Imbel
Type III are forgings.

FMAP
Much ambiguity here: From what I have found the pre-Type III receivers were forgings. There are conflicting reports on the Type IIIs, some insist they are forgings while others believe they are cast.

Armscor (South Africa)*
Presume machined from forgings.

Steyr*
Presume machined from forgings.

Israel
Presume machined from forgings.

Lithgow
L1A1 receivers were forgings.

Britain (all manufacturers)*
Presume machined from forgings.

Long Branch*
Unknown (used an unusual method of manufacturing that I cannot recall).

Ishapore*
Presume machined from forgings.


Aftermarket

DSA
Machined from forged billet.

Coonan
Both Type I and Type III cast.

Entreprise
Early Receivers machined from forgings, later receivers cast.

Century
Cast.

Hesse
Cast.

Essentially this is a request for anyone with knowledge to add facts, especially with regard to differences in machining techniques (which I know almost nothing about). Hopefully this will shed some light onto the differences between manufacturers, and if those differences are significant.

*No appreciable number of receivers were sold to the general public in the US.

[ByronF]

Forging to near-net-shape aligns the metal's structure to follow the final piece's contour. Machined from forged billet means the forged shape is probably a rough rectangle, which is great for a Remington 870 receiver that is essentially a brick (the billet is actually near-net shape, I suppose). Even if the end shape doesn't follow the forged billet's contour it's still a good way to make a receiver.

Grain shape is kind of like the grain in wood. The wood is strongest so long as the shape of the wooden piece follows the direction of the grain. That's why stocks often break at the wrist of the stock if they're going to break at all. But really, what parts of the receiver would even benefit from that advantage? Are the rear sight ears of a Garand stressed to the extent where it makes a difference? Certainly not. The REAL advantage is that the machining goes much faster because you don't need to remove as many chips to get from forging to final machining. So one can invest a lot of money up front in forging dies and reap the benefits of shorter cycle time for the entire length of your production run. Now consider that steel is being rationed. The closer I can get to net shape the less steel it takes to make 1M receivers. I spend less time hauling out hoppers of machining chips. I spend less energy melting the chips back into useful ingots. I use less tooling. I spend less time changing tools. LOTS of advantages to forging to near-net shape, and not all of them translate to a better product for the user. But there is no doubt that a near-net forging has strength advantages, but it's less obvious (to me, at least) whether the stronger structure matters. For heavily loaded pieces like a bolt I'd bet near-net forging matters more than for the receiver (the most important area is only the front 2"). For a Garand rear sight base, who gives a crap.

[jbrooks]

I'm personally interested in the FMAP... I've heard both.

But I have one, and I must say, the front of the receiver sure looks like it is forged. Certainly not cast, that's for sure.

But at least one person on this board claims to have it on good authority (friend from FN Herstal) that the FMAP Type IIIs are cast, because FMAP was a real license with FN, and FMAP mimicked FN.

I must say, my Argy Type III does not appear to be the same material finish as the FN Type III.

So I'm voting "Forged" for the Argy FMAP Type III.

JWB

[nwobhm]

FMAP is forged and fully heat treated.

[gmtech485]

M1 Garand and other USGI receivers were and are forged because the gov spec required it .

Not because it was cheaper or more efficient.
It never has been cheaper or more efficient.
It is definitely stronger that is why it was required.

Now investment casting has come along way's since the M1 Garand.
However if you talk to machinist and metalurgy types they will almost unanimously agree forging is more durable, less trouble to machine, less prone to failure and, pound for pound stronger in high stress applications than castings of the same weight and type of steel.

As for the FMAP receivers , I have no doubt they are forged.
They have none of the tell tales of casting.

I try to go forged when I can and am willing to pay a preimium for a forged receiver over a cast alternative.

However most of us could shoot a rifle built on a quality cast receiver for the rest of our lives and never experience a failure.

Just my preference , I like overkill.

[kev]

This is amazing,................almost historic for this topic. Already five posts to the thread and NOTHING to argue about yet.

I find it hard to believe that there's someone out there who can't tell the difference between a cast receiver and a forging simply from the sound of it. I don't think I've ever owned a receiver(or much of anything else really)that I haven't dropped at least once and it's quite obvious from either the thud or ping at impact how it was manufactured. One sounds like what you might hear dropping from the afterend of a horse at the county fair in the summertime, while the other rings like a bell. I like bells.










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Receiver production line at Century Arms,...............

[moses]

The earlier DSA receivers were machined from a forged billet.
The current DSA receivers are machined from a true forging that resembles the shape of the receiver.
The early receivers started as a 19 lb billet and the new ones if I remember correctly are only a 5lb forging.

DSA's owner told me this a few years ago and said the savings they were getting by only having to use 5lbs of 4140 steel instead of 19lbs was worth the cost of setting up the forging process.

[FUUN063]

IIRC, I believe the early Entreprise receivers were machined from bar stock.

Leland

[gunplumber]

Originally posted by gmtech485
Now investment casting has come along way's since the M1 Garand.
However if you talk to machinist and metalurgy types they will almost unanimously agree forging is more durable, less trouble to machine, less prone to failure and, pound for pound stronger in high stress applications than castings of the same weight and type of steel.

Must be why those jet turbines are no longer forged, but cast.

And given the propensity for DSA to . . . um. . . . LIE . . .. I'd need to hold one of their "forgings" it in my hands and even then I'd be suspicious.

[moses]

I feel ya Mark, what makes me tend to believe them about the forgings now is the fact that 5lbs of 4140 per receiver would be a significant savings when added up over all the receivers they make.
They supposedly got all the original forging tooling when they bought all the Steyr inventory.

[ByronF]

The decision to cast vs forge vs machine from forged billet is probably largely based on return on investment. If you want your payback fast because you don't anticipate a long-term contract milling from billet makes sense. Over a short production run you can't recoup investment for forgings. Better to suck up the waste of dulling lots of tools and filling chip hoppers with wasted metal than investing in forging dies.

If you know you have a long term agreement then forging to near-net shape makes a LOT of financial sense: reduced shipping weight for raw forging (vs. a heavy rectangular billet), less cycle time (less metal to remove), reduced tooling usage (less material to remove). After your dies are paid off you are running for CHEAP. If you don't think your production run will pay off the dies then don't bother.

Quality investment casting isn't cheap, either. If your application supports investment casting then it is a VERY cost effective way to manufacture parts. You can get WAY closer to near-net shape with investment casting. In many applications you can cast to final dimension except for critical dimensions. Don't underestimate the technological requirements for properly investment casting a critical component. I deal with BIG turbocharger components that spin at very high speeds and tend to suck in crap. We do it with investment cast components and forgings.

[gmtech485]

I don't know s#*t about jet engine parts and I cant speak for DSAs machine process nor did I claim to.

My experience is with parts that bang and rub together.

I'm only saying that in my 35 years of repairing broken machinery I have become thouroughly convinced that forged parts fail less often and hold up better. This opinion is supported by many folks I deal with that work with industrial metals every day.

Its a simple statement not a blanket condemnation or recomendation of any particular firearm product.

If I can buy forged or cast I will buy forged everytime.
Will I actually see the advantage over cast?
Where firearms are concerned , I hope not.

[gunplumber]

Some people are stuck on what was better 70 years ago.

[crcksht]

There is little doubt that a receiver machined from a forging is superior to either a cast receiver and a receiver machined from a forged billet due to the superior grain structure of the receiver produced from the forging. Modern casting such as done by Sturm Ruger has been shown to be quite adequate for high-powered rifles and revolvers, though I seriously doubt any cast receiver could approach the longevity(rounds fired before failure) of a forged receiver. Now whether anyone other than the ultra-rich will ever fire enough ammo through a cast receivered FAL to wear it out is seriously debatable.

The reason we have so many M1 Garand receivers still around today which have been rebuilt who knows how many times is due to the fact that they are forged receivers.

[gmtech485]

70 years ago the quality of final product was generally what was most important, not the final cost.

Now day's the final cost is generally what is most important to most companies.

Say what you want about my preferences, most savy gun owners would rather have a forged receiver.

We all know the driving force behind investment casting a receiver is that it is cheaper ,not better.

In the FAL receiver market you don't really save much if any on the over all build by going cast.

Heck anyone who is fortunate enough to have ARS build them a rifle is surely not going to worry about an additional 50.00 more for a forged receiver.

I'm not saying I would not own a cast receiver, I own several and they work fine .
Just that if I have a choice I'll take forged every time.

If you are saying you would rather have cast than forged we will have to agree to disagree.

If you are saying that a quality cast receiver will work just fine then you have no argument from me and never did.

To the OP, sorry this has headed for the gutter. I did not intend to hyjack your thread.

I like forged and I am certain that my Argy upper receiver is forged.

[gunplumber]

There is little doubt that a receiver machined from a forging is superior to either a cast receiver and a receiver machined from a forged billet due to the superior grain structure of the receiver produced from the forging.

A good, modern casting lacks the stress lines that forging puts into the material. There is simply no evidence that forging has anything on casting. 70 years ago, absolutely. We didn't have the casting technology we have today.


But then, marketing people thrive on the ignorance of their buyers.

Like DSA saying "Unlike our competitors, our receivers are fully heat treated".

Instead of "Our receivers do not meet FN's original specification for differential heat treatment. It was too much work, so we just picked an average."

[def90]

Originally posted by crcksht
The reason we have so many M1 Garand receivers still around today which have been rebuilt who knows how many times is due to the fact that they are forged receivers.

I'm also guessing that it is partly because they were manufactured by the millions and the vast majority of them only ever saw the occasional training exercise. I would also guess that any that actually saw serious WW2 or Korean combat saw the junk pile years ago.

[ByronF]

Originally posted by crcksht
The reason we have so many M1 Garand receivers still around today which have been rebuilt who knows how many times is due to the fact that they are forged receivers.

Obviously there is no way to know if that's true or not. There are lots of M1 Garand stocks around, too. Lots of web slings, too. I have a WWII canteen that wasn't forged. Holds water and everything.

There are measurable metallurgical properties, calculations, etc that can determine the number of cycles until a particular failure mode can be expected. This isn't the 1940's and we know a LOT more about metal than we did back then. If your failure mode is bolt lug recession one can make a pretty decent estimate of how many cycles it will take to pound the lugs back until headspace grows out of spec. One can either perform the analysis, or shoot a statistically significant sample size of dimensionally identical cast and forged receivers to failure, or simply throw out statements without any supporting evidence. All three options apparently carry the same level of credibility. This IS the interweb, after all.

I do think forged to near net shape gives a part that is stronger in the direction of the grain. I do not know if the forging is conversely weaker in the opposite plane. Wood is very strong against the grain. But it splits pretty easy with the grain. So who knows. I have forged Imbels and cast M1A receivers. Nothing has popped open yet and I know they won't so long as I feed them good ammo and keep the headspace in check. So the whole discussion is largely an academic argument that gives us something to fight about. I haven't even picked a side yet but somehow I feel like I'm winning.

[moses]

I don't know where the hell we are.............. but we are making great time!!!

[Jaxxas]

From the forging industry perspective! Of course they are biased.


http://www.forging.org/facts/faq3.cfm


How FORGINGS compare to Castings

Forgings are stronger. Casting cannot obtain the strengthening effects of hot and cold working. Forging surpasses casting in predictable strength properties - producing superior strength that is assured, part to part.
Forging refines defects from cast ingots or continuous cast bar. A casting has neither grain flow nor directional strength and the process cannot prevent formation of certain metallurgical defects. Preworking forge stock produces a grain flow oriented in directions requiring maximum strength. Dendritic structures, alloy segregation's and like imperfections are refined in forging.
Forgings are more reliable, less costly. Casting defects occur in a variety of forms. Because hot working refines grain pattern and imparts high strength, ductility and resistance properties, forged products are more reliable. And they are manufactured without the added costs for tighter process controls and inspection that are required for casting.
Forgings offer better response to heat treatment. Castings require close control of melting and cooling processes because alloy segregation may occur. This results in non-uniform heat treatment response that can affect straightness of finished parts. Forgings respond more predictably to heat treatment and offer better dimensional stability.
Forgings' flexible, cost-effective production adapts to demand. Some castings, such as special performance castings, require expensive materials and process controls, and longer lead times. Open-die and ring rolling are examples of forging processes that adapt to various production run lengths and enable shortened lead times.

Here's a pretty cool chart...

http://www.eformulae.com/engineering/tensile.php

[nwobhm]

Originally posted by gunplumber
[B]Like DSA saying "Unlike our competitors, our receivers are fully heat treated".

Instead of "Our receivers do not meet FN's original specification for differential heat treatment. It was too much work, so we just picked an average."

Could DSA have been copying FMAP? FMAP was FN licensed, they heat treated the entire receiver too.

[Brian in MN]

IMHO you guys are tilting at windmills. Where are all the failed cast FAL receivers? Cast vs forged in today's world is irrelevant; especially for the recreational shooter. Quality is not. Buy a Hesse or an Entreprise and you will likely have problems. Buy a DSA, Imbel or a Coonan and you probably won't. The cast/forged argument is a lot of nonsense perpetuated by people who in another time would have been kept up nights trying to figure out how many angels could dance on the head of a pin.

[Brian in MN]

Originally posted by gunplumber
[B]

Like DSA saying "Unlike our competitors, our receivers are fully heat treated".

Instead of "Our receivers do not meet FN's original specification for differential heat treatment. It was too much work, so we just picked an average."

Like you, I am really saddened by the lack of integrity in American business today. DSA has lied to us all. Big time.

Shifting gears, have you seen any problems caused by their heat treatment on the cheap?

[kev]

I feel better now. The noise to signal ratio is back where it should be for this topic.

Turbine blade manufacture really doesn't relate to firearm receivers.

And if a forged receiver will last 200,000rds and a cast receiver will last 100,000rds(or 12,000rds), it's likely that few here are ever going to experience the difference. We'll not be knee deep in worn out cast receivers. Doesn't mean they're equal. It simply means we're incapable of pushing them hard enough for the differences to become apparent.

[VXTip]

this debate will go on forever because we all want to believe our rifle is capable of killing X number of zombies before failure, i know im not the only one thinking that zombie may also be replaced with commi

[ByronF]

Zombies always want someone elses brains, never their own. Commie = Zombie, I guess.

[Ratt]

I've been following this thread for a while, and actually, it inspired me to stop lurking (isn't that what us rodents do?) and post.

I've been a Raw Materials Engineer for both OEM and Overhaul and Repair for aircraft engines.... so I am an expert when it comes to castings and forgings and heat treat.

If you have an application that needs high stress... temps...torque, etc., then a forging is absolutely the way to go. Why many of the arms manufacturers went that direction years ago. Castins are fine if they are subject to the stresses wthin their parameters set forth. Also... if your going to make several thousand, then a investment casting near net is the way to go.

If you can't afford to spend the money to get tooling to make your forging, then a billet material is the next best... and lastly you could go with a casting.

Personally.... make mine a forging...

[jbrooks]

I think one of the reasons that casting the M14 and Garand MAY be problematic is the fact that the dimensions were originally based on forged steel of a particular type.

I understand that Ruger revolvers, for example, are quite a bit thicker in some areas than a corresponding S&W, and that was prsumably to make up for the reduced tensile strength of the casting.

maybe true in the old days of investment casting, but I'm not so sure now.

Ruger makes the 460 Ruger and 480 calibers in cast frames that are thinner than the older Rugers... so I'm guessing that teh science of metallurgy has not stood still opver the past 50 years.

As I always point out, I have a cast SAI receiver that has passed 12,000 rounds and no measurable increase in headspace.

So it's fine with me. Heat treatment is critical.

JWB

[IRONWORKER]

Originally posted by jbrooks

As I always point out, I have a cast SAI receiver that has passed 12,000 rounds and no measurable increase in headspace.

So it's fine with me. Heat treatment is critical.

JWB

+1 - a properly heat treated cast receiver will out last ANY of us - I had a Armscorp M14 receiver that shot out a barrel or 2, other than some finish wear it was hard to tell it from one that wasn't even broken in yet

[randy762ak]

I have a cut up 14 receiver that has set back locking shoulders-thats why it was scrapped .

Comparing forgings and castings is like trying to compare ford -v- Chevy both do the job.
a casting is more rigid It dosent flex a forging will absorb more shock or harmonics.Is a receiver subject to flexing? Id like a solid stiff receiver not one that flex's with each shot -...
I play with race cars I ran a iron duke at 6000 rpm for 3 years with a cast crank and cast rods -cast pistons too. so castings can do the job .
I look at a casting as a very hard strong stable piece of metal that will do the job up to the fail point.a forging will surpass that --? depends on the use .You don't find the main frame of a huge press made from a forging its a casting easy to make stable and solid -But the crank rod might well be a forging....

[Tat2]

When Browning started making Hi-Powers in 40 S&W the forged frames
could not handle the extra power of the .40 loads and gave out. So
they found replacing it w/ a cast frame solved the problem. So I guess
sometimes a casting can be better......

I find this thread interesting since I am shopping for a receiver.....

T

[newtown]

Interesting thread. Here is a fact for thought. Coonan has made 1000's of cast receivers and never had a structural failure. To the best of our knowledge no one has ever reported wearing one out.

[kev]

Has anyone fired one enough to require a rebarrel? I mean, my Coonans appear to be fully the equals of my Imbels sitting here in the rack, being as none of them have been fired. I like Coonans and would not expect to see any difference in the first 10,000rds or maybe even more, but sooner or later I would expect the Imbels to pull ahead. Not that it matters,......................I don't plan to run 100,000rds through any of them.

[1gewehr]

Kev,
I have an Imbel receiver that was built up using an STG58 parts kit in 1995. Last year, at about 18,000rds, I replaced the well-worn 21" ST58 barrel with a near-new chrome-lined Imbel barrel moses cut to 18". After 18,000 rds, headspace had not changed measurably from when I built it up. When re-barrelled, it did not require changing the locking shoulder to have headspace well within specs.

I have only seen one steel FAL receiver that was rendered unserviceable from excess rounds. It was a dealer-sample early Belgian FAL that had an unholy number of rounds fired on full-auto. I do not know the round count, but it had worn out six barrels. Considering that constant full-auto use is much harder on any weapon than semi-auto, my personal opinion is that until you have worn out at least six barrels, your receiver is in no danger or approaching it's end of life.
And when you realize that the early Belgian receivers had less metal supporting the locking shoulder, I believe that any more recent manufacture receiver is probably stronger.

[V guy]

The key part we are concerned about is the portion holding the bbl threads and heat treatment.

Two of the worlds most used weapons, the AR-15/16 and the AK-47 have tiny parts that hold the barrel to the weapon.
The bbl extension in the AR and the bbl trunnion in the AK, are cases in point.

Cast or Forged? Don' t need no 19 lb billet or no 5 lb forgins!! Nope just a teenie weenie piece to hold the barrel.

AR10-308, H&KG-3 to boot ,also use barrel extensions and trunnions. Cast or Forged?

I would be far more concerned with barrel steel than the receiver.

[SKTRGNLDR]

Where's the info on Type IIIs being cast?

[mountainman]

BTW, century is not just cast but then gets machined. also some of the manuf you point out to you say forged as opposed to Near net shap and machined I doubt anyone could 100% forge a pc of steel into a finished recvr. You manufacturing descriptions are kind of ambiguous.

[BloodyCactus]

throwing out a sideways... I work for the largest nuclear company in the world and we cast as may parts as we forge for nuclear reactors. this giant one piece casting is the reactor vessel which contains the coolant AND the reactor core. Its also a pressure vessel.

To say the mathematics and tolerances on this thing is tight is an understatement and it is cast.

we also have a 12000 tonne press dealing with 600 tonne steel ingots. that'd make a pretty well hardened receiver :P

[kev]

Originally posted by V guy
The key part we are concerned about is the portion holding the bbl threads and heat treatment.

Two of the worlds most used weapons, the AR-15/16 and the AK-47 have tiny parts that hold the barrel to the weapon.
The bbl extension in the AR and the bbl trunnion in the AK, are cases in point.

Cast or Forged? Don' t need no 19 lb billet or no 5 lb forgins!! Nope just a teenie weenie piece to hold the barrel.

AR10-308, H&KG-3 to boot ,also use barrel extensions and trunnions. Cast or Forged?

I would be far more concerned with barrel steel than the receiver.

You're missing the big point here. The AR, AK, and HK all have their locking surfaces in the barrel extension or trunion. That's where modern designs shine,................the necessary high quality part is a small, easy to manufature item. The receiver proper can be made out of Silly Putty and it wouldn't matter. All the stress of firing is contained in the barrel/extension/bolt and the 'receiver' is nothing but a bolt channel. The FAL receiver is old world, more like an SMLE receiver than any of the others. Since the locking is done aft of the magwell, the entire receiver must be strong and manufactured with precision.

Hey, are AR extensions and HK/AK trunions forged or cast? Gee, I wonder if we could make some assumptions based on that info? If only we knew,...................

[IRONWORKER]

Originally posted by SKTRGNLDR
Where's the info on Type IIIs being cast?

Ever looked at one? - EZ to tell a casting IMO - All the FN made T3 receivers i have ever seen have a grain structure completely different than a Argie (forged) receiver

[MBR29]

Having worked at DSA for 3 years I will state the truth on this

DSA receivers are made from a drop forging of 4140 steel. The drop forging is shaped in the general shape of a FAL receiver for reasons of saving on loss of steal purchased and for their type of fixturing.

I ASSURE YOU ON MY KIDS LIVES current DSA recievers are machined from a drop forging I've held them at least 100 times. A couple of FAL Files members have seen this and it has been displayed at SHOT show and other shows.

NO STORY HERE GP find a new story to run with.

Nuff said on that.

[gunplumber]

then it is a change.

I wonder if this corresponds with the dimensional problems DSA has been having over the last few years.

I take it LMT is no longer machining them for DSA?

[SKTRGNLDR]

Ever looked at one? - EZ to tell a casting IMO - All the FN made T3 receivers i have ever seen have a grain structure completely different than a Argie (forged) receiver

I was in the firearms manufacturing biz for 30+ years and made a lot of parts from castings. Unless someone can prove otherwise, in my expert opinion, the Type IIIs were NOT cast.

I was just hoping for some PROOF before commenting.

[jbrooks]

Maybe not proof, but Blake Stevens said the FN Type IIIs were cast.

JWB

[SKTRGNLDR]

Maybe not proof, but Blake Stevens said the FN Type IIIs were cast.

He said...she said...ya gotta reference?

[MBR29]

DSA receivers have been drop forging for the last 3 years at least. As for changes not sure lots of things could come from that.

[nwobhm]

Originally posted by SKTRGNLDR


He said...she said...ya gotta reference?

Do you have a reference that says their forged?

[IRONWORKER]

Originally posted by SKTRGNLDR


I was in the firearms manufacturing biz for 30+ years and made a lot of parts from castings. Unless someone can prove otherwise, in my expert opinion, the Type IIIs were NOT cast.

I was just hoping for some PROOF before commenting.

How about some PROOF that they aren't cast

[IRONWORKER]

Originally posted by SKTRGNLDR
I was in the firearms manufacturing biz for 30+ years and made a lot of parts from castings. Unless someone can prove otherwise, in my expert opinion, the Type IIIs were NOT cast.

Oops, didn't know you were a "expert" i must be wrong

[gunplumber]

I've never seen anything resembling a mold line on an IMBEL. That isn't definitive, but mold lines are easily discernible on the FAC, Coonan and EAI.