As the acknowledged gun expert in PDFF and as one of your fans here, I would like to request you to design an assault rifle for the army that would at least be an improvement over the M16A1, it need not be original, just buildable with materials and equipment available in the country and at reasonable cost.

Okies?

:specool:

Ayos ito ah? okay, let's start off with the mission requirements. Let's set some rules first before we design it. I'll start with the specs first.

1. Its a derivative of the M16
2. It will be a rifle chambered for the 5.56mm NATO
3. It will at least have a 20 in bbl and 16 in bbl for a carbine version
4. It should weigh less than 3.4Kg
5. It should be able to accomodate 55 gr and 62 gr ammunition
6. It should have internal fit that allows fouling after 100 rounds fired with the residue density of powders used by the Goverment Arsenal.
7. It should be able to shoot 1 MOA from 25m up to 300m (1 inch hit probability at 100 meters)
8. It should have a rear and front sight system that can be adjusted both for windage and elevation, at 1/2 MOA intervals.
9. It should have a unit cost below 75,000 pesos for the first 1,000 pieces and goes down subsequently, net of capital expenditure (which may be duly subsidized, through gov't guarantees)
10. It should have a trigger pull weight of 4 lbs.
11. Selective fire should be available for either semi or auto discharge, with options for finite burst capability.

Will these specs be okay with you guys?

awright thread, very original :thumb:



I guess we're stuck with the 5.56mm since changing to higher caliber would entail ammo supply problems...other than this your initial specs sounds OK

what is the production cost of locally made M16A1? isnt 75000 for this new design ummm , still too expensive? :dunno:

It is, that's why I spec'd a 1,000 piece run, that's considering no major components are made locally, all parts are imported from parts manufacturers. a 1,000 piece run can not justify local capital expenditures to setup manufacturing. Give me a volume to work with let's say three years and we can adjust the price ceiling. :dunno:

ya i get your point now...subsequent runs can of course lower costs

:thumb:

guys, let's allow CDF to come up with a rough design first before nitpicking over it...

pahabol CDF - include rail system for the carbine ala M4. :aberet:

1. Its a derivative of the M16
2. It will be a rifle chambered for the 5.56mm NATO
3. It will at least have a 20 in bbl and 16 in bbl for a carbine version
4. It should weigh less than 3.4Kg
5. It should be able to accomodate 55 gr and 62 gr ammunition
6. It should have internal fit that allows fouling after 100 rounds fired with the residue density of powders used by the Goverment Arsenal.
7. It should be able to shoot 1 MOA from 25m up to 300m (1 inch hit probability at 100 meters)
8. It should have a rear and front sight system that can be adjusted both for windage and elevation, at 1/2 MOA intervals.
9. It should have a trigger pull weight of 4 lbs.
10. Selective fire should be available for either semi or auto discharge, with options for finite burst capability.

Optional Items
1. Carbine version with 16 in BBL
2. MIL 1913 Picatinny Arsenal Accessory Rail Interface System
3. Provisions for M203 Attachment, Rail and Barrel Nut Interface

Terms of Delivery
1. It should have a unit cost below 75,000 pesos to be delivered with 12 months of PO.
2. 40,000 units will be ordered considering 60% local manufacturing of major parts of the rifle with a celing price of 40,000 pesos to be delivered in a span of three years with price increasing at 4% + inflation rate.
3. An open L/C (local) in favor of vendor charges paid by Purchaser payment contingent upon issuance of proof of delivery to purchaser.
4. Purchaser provides guarantees for manufacturer to purchase capital equipment to manufacture 60% of items for delivery.

I included terms of delivery to assume viability for local manufacture so capex is not an issue in determining price per unit.

Woops less than 3.4kg weight - give me one! I can almost see that baby in my hands.

Cool thread. :armysmile:

Edit: CDF, have you considered a bullpup design?

Interesting. It would be nice if CDF can include line drawings of his design.

Who knows, the powers that be that lurk in this forum take notice, and presto, we have a new indigenous rifle to replace the M16.



:thumb: Hey, a little imagination harms no one.

Mas maganda bullpup kasi yan ang uso ngayon, Tavor at Steyr na lang ang basehan mo CDF.

I was thinking about it, but based on the constraints about plastic forming technology and composites (i.e. thermold raw material), we can not quantify base costs. Let's just do a basic rifle first then, let's start from there. Will that be a good compromise?

Fine with me, I dunno with the others but I suggest to the guys that we let CDF build the basic AR first then lets 'quarrel' over the derivatives later.


:aberet:

:agree:

That's settled then, its a non bullpup rifle, for the meantime.


Before we talk about design considerations, let's start with the current M16.

The M16 is a varmint caliber shooting rifle where the action utilizes direct gas operated locking system. It deviates from dual opposing bolt lug system by utilizing an 8 lugged bolt & bolt carrier system. It divided the surface area of the lug into several small lugs hereby changing the "unlocking angle" instead of the usual 90 degrees of dual opposing lugged turnbolt rifle (i.e. bolt actions), the M16 uses a 20 degree turn to unlock the rifle's bolt. Thus it has the lug surface area of turnbolt but the bolt only have to turn 22 degrees.

Furthermore, its designers, is first to innovate with barrel mounted locking system (instead of the usual receiver mounted locking). The locking system, using a barrel extension, hereby decreases the stress on the whole receiver, allowing the whole receiver system to utilize lighter and non high surface hardened metals and alloys (i.e. aluminum instead of steel). The M16 utilizes forged T6 aluminum receiver. The barrel and barrel extension assembly is secured in place by using a barrel nut that mates it with the aluminum receiver.

The bolt carrier carries the bolt and receives gas from the far end of the barrel. The bolt carrier is non rotating, while the bolt head rotates to disengage the action locking system. The bolt carrier moves forward on battery and rearward on recoil. While the bolt head is cammed into the bolt carrier. Everytime the bolt carrier moves rearward, the bolthead is cammed to rotate, thereby unlocking the bolt from the barrel extension/ breech. The system is closed bolted by use of a recoil spring system mounted directly in axis to the rear of the rifle, which is embedded into the buttstock.

The receiver system is split into two, the bolt action parts as the upper receiver, while the trigger, hammer, magazine column, recoil spring system. as the lower receiver. Both are made of aluminum.

Drawbacks to the M16 system.

1. Gas fouling, is a result of the direct gas operation system of the M16. The propellant residue along with the gas is pumped back into the bolt carrier to operate the action. Fouling causes jams of all sorts into the rifle. The propellant residue, clogs the bolthead, the chamber causing these components to resize its functional tolerances.

2. The bolt carrier travels into a portion of the lower receiver while it is mounted in the upper receiver. This axis, may not be true against each other, hereby causing wider hit probabilties.

3. The Magazine and magazine column, mounted on the lower receiver, does cause a slight rotation (a fraction of a degree) in the bolt carrier. This does not affect accuracy unless it rotates inconsistently. Accuracy related trouble to mag column fit starts to occur the ff reasons,
-a new rifle mates and fits the the two receivers tightly,
but because of the porousness of aluminum, it degrades this mating integrity as the rifle comes to age.
-This is usually caused by recoil standing waves ( the recoil that reflects forward after it reaches the rearmost of the rifle) that terminates in the mag column area.
-This movement pitts the mating of the lower receiver making it to "play", sidewise.

All drawbacks have effects on reliability, availability and accuracy. Preventive maintenance against these drawbacks maintains the operational record of this rifle.

On the other hand, the M16 have its merits

1. It uses the less number of parts
2. It have allowed the use of synthetic furniture
3. It is light (3.4 Kg)
4. It is accurate

do we have a master gunsmith as good as CDF in the AFP's R&D?

The AFP should hire CDF!!!! :specool:

from where he is now, i think the afp cannot in all likelihood match cdf's earnings...my hunch is cdf owns a gunshop or a gunstore

Kabayan, I would like to know if there are companies in the Phil. that still manufacture the M16 receivers? I know that ELISCO used to be but they already folded up. If none why cant our country start to manufacture those Receivers. There are a lot of foundries here in the USA that supplies forged M16 receivers. We call it 0% frames and all you need to do is machine out the magwell and fire control well. The last time I checked it each forging cost around $26.00 for the upper and $30.00 for the lowers. No paper work was requiered since it is not a complete receiver and a lot of people(civilians) here have been building realy accurate rifles from their garage. :armygrin:

try to check it at www.ar15.com and www.roderuscustom.tzo.com

FYI the AR15 was the civilian version of the M16 here in the USA.

oh we know this and of course we know too that this un, like the M16 sucks. :demon:

think about this.

the AFP cant afford to hire a gunsmith with a skill like that of CDF!

what they do have in abundance ..... IS THE HORDE OF GUN- SMUGGLERS.

:funnypost:

but seriously :bs:

Those sources you mentioned are good sources nevertheless, cutting off the magwell with its irregular contour is difficult to achieve without the proper equipment. Some US 0% builders file off the mag well contour after doing the best milling cut they can acheive.

If I wanna build a receiver from forging's I'll purchase the version where the mag well is already cut to size and fit. They usually cost a few dollars more.

As for doing the forgings locally, the AFP does not commit to buy before manufacture, the proponent should invest on the forging moulds which can hit 10,000 dollars, another option is casting the receivers, but it has been seen that casted receivers do not have even stress points and will break with due stresses in normal operation.

Reengineering the M16.....The new M16 design

Receiver Design

Building the next generation of M16 can take several paths, like the H&K 416, which utilizes an op rod mounted on a piston. The piston is the last point of fouling, while the op rod pushes the bolt carrier, making the rifle indirect gas system. It does prevent fouling, mitigating drawback no.1 but does not address drawback nos. 2 & 3 as they opted for compatibility with existing lower receivers. The drawback it creates is expensive manufacturing. The piston and it the operating rods have to be machined to tight spec but still allows the rod to operate without creating piston gas blow-by.

I for the purposes of this excercise will opt not to mitigate drawback no.1(fouling), as operational records shows (SR, PMC etc) that careful maintenance of the rifle and disciplined operational use (i.e. limited use of automatic fire but more on aimed fire) can mitigate fouling related problems. Fouling can be co exsited yet as the option to mitigate the fouling results in addition of parts that can multiply the "points of unreliability" to the proven system ( a simple statistical fact, even on airplanes).

I therfore propose that the M16 be rengineered according to the mitigation of drawbacks 2 and 3.

First of all, deviate from the two piece receiver design, by creating three piece receiver. One receiver component holds the bolt carrier, action and barrel, second receiver components is the mag well and magazine ejection components and lastly the butstock, trigger and trigger handle component. It should be using the same components used in the existing M16, sans the receiver and the pin system to hold the receiver together.

Advantages of such system

1. Recaliber of the rifle, since the mag well is a detachable piece, re caliber of the rifle does not have to be confined with the 223 remington cartridge size. Better cartridge configurations can be used without resorting to the geometry of the 223 rem size widths as you do not have to conform with magazine limitations. Still it will be limited in length of the current bolt carrier movement span.

2. standing waves banging on the mag well terminates in the trigger area instead, as the point of transmission is the pin that holds them together, thus isolating this critical area.

3. The pivot pin can now be located in the trigger mag interface point and can be be still cleaned according to normal cleaning procedures.

Secondly, the source of all non true rearward action of the bolt carrier is the rear geometry of the upper receiver to the buffer spring tube. This is currently configured as a quarter circle diameter, this can be re configured to utilize a straighter geometry (either section of a triangle or angled cut), it has always been a manufacturing hassle to true two circular parts together but parallel lines are easier to machine and fit. It can also be incorporated with a rail capture system to maintain true axis between the bolt and the buffer tube.

Impact on manufacturing

These design changes does not require abrupt changes in manufacturing, the magazine can even be made of machined engineering plastic like the HK G36 if opted to. Aside from addtional tooling for the third receiver part and three more pins, the process is closely similar to the standard M16.



What do you guys think? :dunno:

:bow: well, colddead so far so good, so far its making sense

specially about the three piece receiver redesign (i.e like you said easier to mod barrel as well as the trigger group)

I wish we could see it with CAD or SolidWorks, if anybody knows how..

This design sounds like an FN FAL type rifle. Well it looks good to me. Lastly those M16 forgings can be ordered with the MAGWELLS have been pre-cut through EDM (Electrical Discharge Machining) for an extra $20.00

If your talking about the seperate trigger buttstock lower receiver, then yes, but the FAL have integrated the mag column well in the upper receiver. then that makes it a no at the same time. Nevertheless it borrowed concepts from the FAl and the G36.

Actually, the better option is to go with a two piece system, but place the magwell integrated with the upper receiver like the HK stamp metal rifles and FAL. The only drawback is in manufacturing. The square shaped well is difficult to machine without a back hole (like the M16) and much more difficult with EDM as wire cut EDM requires a starting hole through out. The other option is to use die sinker EDM used by plastic mould makers, The last and final option is to use investment casting (which I hate, preference ika nga).

I can now imagine the design choices of the builders of the FAL and HK. FAL went with a open rear system for their upper receiver but this point is critical to proper magazine engagement, which HK opted by welding stamped metal sheets.


This is fun :demon:

Why not do away with full auto fire and limit to 3-round burst and semi-auto only ?

I want to do that in the outset of the design specs, but two issues emerged......

1. There are still "full auto" hold outs in the AFP. Their idea of assualt is "charge of the light brigade"

2. Second the M16 burst system, is a "memory" burst system made of a ratchet and a second disconnector. The problem with this system is that it is not finite in burst shot count, sometimes it spews 3, sometimes 4 sometimes 5 and the trigger break weight is so damn heavy.

I wanna rethink the burst system carefully, it should be " finite" burst not a hit and miss shot count of the "memory burst system".

So I considered that as an option as we let our design mature. I will count on you to remind about it.

agree with iron drag, cancel full auto fire to force the troops to practice fire discipline by limiting them to 3-round burst and semi auto only...besdies full auto has been proven time and again to be just a waste of ammo.. all bark and no bite

Pretty solid to me, just a little clarification on re caliber capability, are you thinking of a quick barrel change set-up similar to the Lewis Machine & Tool carbine?

verry interesting thread!!

colddeadfish are you not finish with the design yet?

Singa Lion,

Not yet, this is suppose to be a paper exercise. You may have inputs on the spec, throw them in before we get far into the design. It is a fact that Singapore (through Chartered Industries) and Philippines (thru Elizalde Tooling Company & ELISCO) were the first two countries to sub license the M16 from Colt in the late 70s. These two countries were in the forefront of 5.56mm weapons design before NATO countries started development on fighting systems based on these calibers.

Hey CDF check out this site www.geocities.com/elmgrove1765/ he did a scratch built AR15(civilian M16) from aluminum plates. He inspired two garagesmiths to build a FN-FAL type rifle from steel plates and another guy built a LAR GRIZZLY .50BMG type sniper rifle. Well I hope this will give you guys some idea. :thumb: I am sure pag-kakaguluhan ito sa Danao, Cebu :armyLol:

Danao gunsmiths are very skilled as long as they have an original design to copy, I was shown two NAA Black Widow revolvers, one original and the other a Danao-made counterfeit . When I was asked to pinpoint the fake, I mistakenly pointed at the original!

for curiosity's sake... baket andami yatang gunsmiths sa bandang Cebu (from what I can gather from the posts)?

CDF, can you pls tell me what kind of manufacture do you have in mind for this AR project? when you're talking about the gun design, do you have in mind if you're going with sheet metal/aluminum/ stamping manufacture or polymer as much as possible.. from what I can read it seems you are keeping in mind to keep the cost down..

thanks

Yup I have seen this site before, this guy is a hobbyist and uses a sherline scale model machining system. Anyways, his method is good for small production runs, but if you go after the benefits of "marginal costing", forgings is the way to go.

The urban legend started after the war, James Cushing Guerilla group operating in cebu started manufacturing shotguns and pistols to support the logistical need of the underground. Furthermore, they improvised mortar tubes using bamboo reinforced with GI wire wrapped around the tube and a initiator pin using scrap rail steel salvaged from J Cushing's mining claim in Cebu (now the famous ATLAS mines).

I would start with forgings as it cuts a lot of machining steps in building the receivers. The question is do I make the forgings locally or abroad. If the volumes can sustain it profitably, why not make them locally. Tooling options is determined by assumed order quantities to ensure ROE and ROI of the project.

if they are that high skilled then they should design their own arms rather than copy other designs

Hey dude even your SAR-21 is not original, its just a copy of the Steyr and other bullpups. :demon:

Just a suggestion to ColdDeadFish, why not go for a more powerful chambering, the 6.8mm for example...


:aberet:



Regards,

HG aka Greenbug