Posted on 01/22/2013 12:24:43 PM PST by varmintman
The real stupidity of this entire business starts to sink in when people start to grasp the realities of the basic M4/M16/AR15 rile.
The M16 is a simpler weapon than an M14 or a FAL rifle. The ONLY thing about an M16 which is even a tiny bit difficult to manufacture is the barrel. Unlike a FAL rifle whose upper receiver has to take the stress of firing and which has to be hard forged and whose barrel is fitted to the receiver with something like 130 ft-lbs of torque, the only thing which takes any stress in an M16 is the barrel, the bolt carrier locks into the breach of the barrel and not into the receiver.
Also unlike the case with a FAL, the lower receiver of an M16 which, for all intents and purposes could be made of plastic, is the legal part of the gun i.e. carries the serial number. Ordering a complete upper receiver and barrel for an M16 is legally the same as buying a sack of potatoes, don't take my word for it check it yourself:
http://www.gunbroker.com/All/BI.aspx?Keywords=m16+upper
http://www.gunbroker.com/All/BI.aspx?Keywords=m4+upper
Anybody with any sort of a machine shop could manufacture M16 bolts, bolt carriers, triggers and springs and what not. No joke. My next door neighbor builds race-cars and he ends up needing parts which don't exist in the world here and there... No problem, he draws what he needs up on AutoCad, takes the AC file to a shop with computer controlled machines and voila, and it doesn't even cost much.
Very shortly, people will be making M16 lower receivers, butt-stocks, and magazines (the evil 20 and 30 round types) with inexpensive 3D printers and the only way you could get past all of these problems would be to ban and outlaw the M16 altogether, which would leave our military standing around with, in the immortal words of Santino Corleone, just their.... (in a sort of an unarmed condition).
“The ONLY thing about an M16 which is even a tiny bit difficult to manufacture is the barrel.”
IIRC, mine in Vietnam was manufactured by Frigidaire.
I don’t think they’ve made it past 80 rounds with a printed lower receiver before it cracked. At this point it would be more like a throw away gun.
Clarification.
My ENTIRE M-16 was made by Frigidaire! (or at least, their name was molded into the lower receiver.)
Cool
Ding Ding Ding!!!
We have a WINNER in the Pun of the Day contest!
One can do a lot with 80 well aimed rounds.
Level of difficulty has nothing to do with the issue.
At stake is whether or not free men ought to be armed. Period.
They should; to defend their liberty from all who would abuse, usurp and become tyrant over them.
As an aside, the critical components of the AR or most any other weapon for that matter is heat treatment of proper steels. The AR bolt does not lock into the breech of the barrel, but rather into a barrel extension, which is screwed onto the barrel breech, very much like a bolt actio or most all other actio types. It, the boltand carrier are made of not too common (but not rare) steels heat treated to be extremely hard, tough and wear-resistant.
It's a dandy little weapon for close in fighting in relatively clean environments...but the more-complex-to machine M-14s and FALs work more dependably in all environments, defeat all known body armor/light armor/cover and are effective at longer ranges.
Depends on how much you value your own life, I guess..
“I don’t think they’ve made it past 80 rounds with a printed lower receiver before it cracked.”
That is strictly a developmental problem. Go to greater wall thickness in the weak areas, sprinkle a few glass or Kevlar fibers between printed layers.
Lots of possible solutions.
> “I don’t think they’ve made it past 80 rounds with a printed lower receiver before it cracked.”
The first one made cracked in something like 3 or 4 rounds. It was an exact duplicate of the AR15 receiver only in plastic. Some changes were made to reinforce it at the weak point (which means it is no longer MIL spec dimensionally, but it still worked), and it made it to much higher rounds.
I have no doubt that they will work in some more dimensional changes and it will get to even more rounds. In addition, there are metal 3-D printing machines available now (but not at a reasonably low cost) that will become even more available in the next few years. The only reason this is happening now is that plastic 3-D machines are available at reasonably low cost.
Gun companies had better be looking into this technique if they want to stay in business. The music and movie industry did not deal with the “new information age” and they are having problems because they did not adapt.
Remember when lost wax castings came into being. The old companies would have no part of it. Some are no longer here. Several others are struggling. A new company (Ruger) did not invent it, but embraced it wholeheartedly. Look where they are now.
The M-16 is a weapon that must be cleaned, very often!
“I don’t think they’ve made it past 80 rounds with a printed lower receiver before it cracked.”
That is strictly a developmental problem. Go to greater wall thickness in the weak areas, sprinkle a few glass or Kevlar fibers between printed layers.
Lots of possible solutions.
Try making the lower receiver out of carbon fiber or carbon nano tubes.That stuff is supposed to be stronger than steel.
I'm sure common o-2 tool steel would work. It is available everywhere at any tool supply. It is easy to heat-treat with just a torch and a bucket of oil.
Well ... I wasn't there ...
But it's entirely possible that the only part of your M-16 manufactured by Frigidaire was the lower. One feature of the design is that parts can easily be made anywhere and put together at a facility that manufactures nothing. Like, for example, your garage.
Frigidaire Division of General Motors, you mean. That's the one that was located in "The Arsenal of Democracy" before it was destroyed by liberalism.
I recall fondly my M-16A1 in boot camp. The best part of the rifle range was actually shooting. I shot 10 bulls eyes at 500 meters. When we weren’t shooting the DI’s were putting us through all sorts of hell so we all wanted to shoot more.
With a standard gas impingement system, this is correct. 1500 rounds is the most that made it through an acquaintance’s RRA before it started to hang (occasional addition of lube). The piston guns run cleaner and can go longer with less attention.....they are also a bit heavier in the front.
i wonder how difficult it is to make a sear trigger with a 3-d printer...
That they went from nothing to 80 rounds in a few months of part time puttering should be rather sobering.
Won’t be long before those chinchy little 3D printers are churning out solid metal parts ready for tempering.
M16 craps where it eats. The only military rifle with direct gas operation.
“The M-16 is a weapon that must be cleaned, very often!”
Disagree. There have been numerous torture tests where many thousands of rounds were fired without cleaning and without malfunctions. The key to reliablility is to keep them well lubed. I will admit they do get filthier than any rifle I have ever seen but it doesnt seem to effect functioning.
Learning Curve ~ they’re just starting ~
Sometimes you'd get a really experienced lecturer who could tell you why the Chinese weapon had a piece of wood in it under the bolt, and the Russian weapon didn't, and why they did that.
Everybody who designs firearms for use in the field worries a lot about how to keep them clean and working under very adverse conditions. Designers have all sorts of solutions ~ and during the Nam they were all found wanting, discarded, and replaced with other solutions.
The new generation of home built firearms will need to be designed for looser tolerances ~
The extension threads onto the chamber end of the barrel and becomes essentially part of the barrel. Never heard of anyone removing the extension, though I am sure it has happened.
Therein lies most of the accuracy inherent in the AR platforms, the bolt and barrel assembly are darn near independent of the rest of the parts.
Good write up.
“When we weren’t shooting the DI’s”
Shooting DIs? They didn’t give to you a dishonorable discharge for that? Why aren’t you in prison? :-)
At a gun show, I once saw an M1 carbine that was stamped "International Business Machines". I should have bought it, just to show it to my software developer friends.
With the M16 and variants, over the years one thing has changed a lot. That is lubricants. The slickest one I have found is “Tec-Shield CLP”. It is water based and lubricates at a molecular level. It seems to overcome many of the weakness of the M16 system.
Yep ...
M1 Carbines were made by a bunch of unlikely contractors, including Rock-Ola, Underwood, National Postal Meter, and several divisions of General Motors.
I wasn’t being critical when I stated that 80 rounds before failure has been the record so far. I’m sure the kinks will be worked out over time.
When we reach the point that entire firearms can be cranked out by any Joe in his garage, the whole gun control issue will be a moot point.
The M-16 is a weapon that must be cleaned, very often!
During my six years of service in the Air Force I found the M-16 and its shorter variant,What we in the K-9 field called the GAU to be very good rifles.
The problems were not the rifles the problems were the cheap Ammunition the government procured during the Vietnam war and the period just after that.
If they bought smokeless powder for that Ammo,The M16 would have been a dream.
With the Cheap Ammo that rifle would gum up and become a filthy mess.So it was really important to clean right after use.
The funny thing is you can’t buy an AR15.
They are sold out nationwide. Just not available. I’ve tried.
“So it was really important to clean right after use.”
Thank you for that clarification.
With that cheap Ammo from the Vietnam war,YES.it needed serious cleaning.
With modern Smokeless powder Probably not as much since Smokeless powder burns much cleaner.
“You admit as much yourself whenyou say:
“The key to reliablility is to keep them well lubed.
I will admit they do get filthier than any rifle I have ever seen but it doesn’t seem to effect functioning.”
Just because it gets dirty doesnt mean it HAS to be cleaned very often. You might find the article below interesting.
My Cousin was in The Hill Fights in 1967 with the Marines, the Marines with drew the M-16 until Mods were made. It was still unreliable.
>>>>“The ONLY thing about an M16 which is even a tiny bit difficult to manufacture is the barrel.”
>>IIRC, mine in Vietnam was manufactured by Frigidaire.
Various armories were making pretty darn good rifled barrels well before the advent of AC motors. The Colt armory in Hartford, Liege in Belgium, Steyr in Austria, Tula in Russia (well before the USSR), etc.
This stuff isn’t rocket surgery, people.
“My Cousin was in The Hill Fights in 1967 with the Marines, the Marines with drew the M-16 until Mods were made. It was still unreliable.”
No doubt. Early development and testing of the M16 used an extruded powder and it worked so well the army decided the rifle didnt need cleaning. In fact they didnt even include a cleaning kit. The reliability issues started when they changed to a ball powder with the wrong burn rate. They fixed that 40 years ago.
That's because the military uses Winchester ball powder ammunition instead of Remington IMR “Improved Military Rifle” which was what the M16 was designed to fire. It's a much cleaner power that the army in it's infinite wisdom decided not to use. Kind of like using rifle muskets in the Civil War instead of lever action rifles because the Quartermaster Corps decided it was a waste of ammunition.
I have one made by Underwood.
I saw a DPMS A-15 (Plain vanilla A2 model) at a gun show on Saturday ... price tag was $2400 ...
It would be really cool to see a full collection, one of each make.
Yep. Big part of the problem was/is the propellant. Stoner’s original design called for a chemical that after burning would deposit a thin film like graphite, contributing to lubrication. Olin had the ammunition contract at the time and said no to the new propellant. The vagaries or acquisitions and the lack of a chromed chamber and bore were the reputation killer of those first m-16 rifles.
Cheers
Well, there’s a couple details you sort of blipped over.
In order of complexity of manufacturing, I’d rate the parts on the AR-15/M-16 in this order:
1. barrel. Obvious. Deep hole drilling is part art, part science. Reaming and rifling can be done reasonably easily, but slowly. Getting the initial hole through the barrel stock and mostly straight is a challenge and requires high-pressure lube/cutting fluid, as well as that fluid coming out the cutting bit used for the deep hole drilling.
But for someone with some skill, they can make their own deep hole drill. It’s been done.
2. The bolt & carrier. Lots of fiddly little machining, but possible. You’ll need a super-spacer or indexing head to get this done on a Bridgeport.
3. The barrel extension. This is the bit you sort of blipped over... the back end of an assembled AR-15 barrel is a “nut” that gets screwed onto a threaded and chambered barrel. The tenon on an AR-15 barrel is supposed to be 0.6200” long, 0.8125x16TPI, Class 3 fit. The finish reamer is sunk deep enough into the barrel that a go gage sticks out by about, oh, 0.129” for a spec barrel extension and a spec bolt.
But even after machining this all in at tight tolerances (this is the part of the AR-15 that has anything remotely resembling tight tolerances), unless we used pre-hardened 4140 for the bolt and the extension, we’ve got to harden both parts and draw them back a bit. Not difficult, but not something that most people making their own are going to remember to do, and their bolts and/or extensions will wear too quickly and the headspace will open up in time.
The fastest way to get around the heat treating is to use pre-hard 4140 and then use carbide tooling to make the extension and the bolt.
When you have the extension done, then you’ll have to torque it onto the barrel to 150 ft-lbs of torque. This will result in about 0.002 of crush on the tenon shoulder and the extension. Once this is to spec torque, you’ll have to drill the 0.125” hole through the extension on the frontmost part of the cylinder that gets put into the upper receiver, then put in the indexing pin for keeping the barrel oriented correctly in the upper receiver.
Then you’ll have to reckon your gas port size, make a gas block to fit your gas tube, put it on the barrel, etc.
Once that’s done, the rest of the job is a downhill run...
I'll bet there are collectors out there who have such an array of M-1 Carbines. I have but one and I think it's really neat.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.