FN FAL Rifle

Fig 1 Right

Fig 2 Left

Fig 3 Scope

Fig 4 Solingen Bayonet

Fig 5 22 Sub Caliber Adapter

Fig 6 PVS-4 Starlight Scope, Night Vision Sight, Individual Served Weapon

Background

Markings

Video

YouTube - FN FAL (full disassembly and operation) - computer animated

Related

Ballistics

Trijicon CCAS Continuously computed aiming solution 50 - 2000 meter auto ranging, baro pressure, inclination,
4806007 Optical gun sight, Glyn A. J. Bindon, Armson, Inc., Feb 21, 1989, 359/424, 42/122, 359/429, 359/431
7676137 Optical sight, Darin W. Schick, Newton Quan-Chung Kwan, Timothy H. Miller, Jerry Glen S. Elpedes, Trijicon, Inc., Mar 9, 2010, 385/147, 385/134, 42/111, 33/298, 42/132, 33/297 - has provision for digital data in field of view. - What is model number of just scope with data display?

Rifling

New Principles of Gunnery 1805 (Free Google Book) has papers from the prior 50 years.  The first 380 pages are about interior and exterior ballistics of round projectiles fried from black powder guns (3/4" lead balls and 24 pound iron balls).  In those pages he shows that air resistance greatly reduces the range you would get in a vacuum and so the trajectory is far from parabolic.  I expect this is also true of dumb bombs, that's to say the trajectory is far from parabolic.

In the section titled  On the Nature and Advantage of Rifled Barrel Pieces the reasons those on the continent (Europe) said were it's advantages are:

• that the inflammation of the powder was greater by the resistance, which the bullet thus forced into the barrel gave thereto, and that hereby the bullet received a much greater impulsion, than it would have done from the same quantity of powder in a common (smooth bore) piece, or
  
• that the bullet by the compounding of its circular and revolving motion did, as it were, bore the air, and thereby flew to a much greater distance, than it would otherwise have done ; or
  
• that by the same boring motion it made its way much easier through all solid substances, and penetrated much deeper into them, than if discharged in the common manner.
  

The projectile was a round lead ball, either forced into and down the barrel where the lead deformed to match the barrel or in a leather patch where the lead was not deformed.  The latter had much higher muzzle velocity because there was much lower friction, but still for the same powder charge used with the smooth bore the velocity was lower than a smooth bore.

The author then makes that case that the main advantage is that the effect of air resistance on a ball with any defects (in Cg or aerodynamics) will be averaged because of the rotation of the ball. (This is the stability improvement provided by rifling, not the gyroscopic effect which is destabilizing)
But, he also says "And in the first place I must observe, that though the bullet impelled' from them keeps for a time to its regular track with sufficient nicety; yet; if its flight be so far extended, that its track is much incurvated, it will then of ten undergo considerable deflections. This, according to my experiments, arises from the angle at last made by the axis, on which the bullet turns, and the direction in which it flies; for that axis continuing nearly parallel to itself, it must necessarily diverge front the line of the flight of the bullet; when that line is bent from its Original direction; and when it once happens; that the bullet whirls on an axis, which no longer coincides with the line of its flight; then the unequal resistance described in the former papers will take place, and the deflecting' power hence arising will perpetually increase, as the track of the bullet, by having its range extended, becomes more and more incurvated."

Note in none of the above arguments (both European & English) is improved accuracy a benefit of rifling.  In the case of the English analysis it helps accuracy at short ranges by averaging imperfections in the ball but at longer ranges causes a lot of problems (because of gyroscopic action).

But he didn't do any experiments relating to the amount of powder that's useful in rifled barrels.  Remember with black powder that once the bullet leaves the muzzle any unburned powder is pushed out and will fall on the ground (easy to detect if a white bed sheet is on the ground).  I expect that you can use more power to useful effect in a rifled barrel, confirming the first bullet above leading to higher muzzle velocity.

Wiki: Alfred George Greenhill, formula for rifling twist for stability
Wiki: Miller twist rule - supposed to me more accurate than the Greenhill formula.

It may be the case that a modern smooth bore gun using a round made from material with uniform properties throughout would be more accurate.  That in fact is the case for modern long range artillery (Wiki: Gerald Bull, Project HARP, Super High Altitude Research Project, Other web pages:  Operation Plumbbob (Scroll to Test: Pascal-B), Learning to Contain Underground Nuclear Explosions)
Note Pascal-B was the second underground nuclear test where the ground level cover (a 4' diameter 4" thick steel plate (about 1 ton weight) was blown off at about "Six times the escape velocity from the earth."
This was caused by many tons of concrete that were vaporized by the explosion that went up the shaft and propelled the cover.  The cover vaporized like a meteor.

Picatinny rail, MIL-STD-1913 rail, 2324 rail, or tactical rail, (Wiki)

eBay seller outdoorzone described as: "11.5" 2-Piece FN FAL .308 Rifle Weaver/Picatinny Aluminum Mount Accessory System"

F7g 7

Rail Patents
5704155 For holding and aiming accessories for a firearm, Daniel F. Primeau, IV, Jan 6, 1998, 42/114, 362/249.11, 362/110, 42/146
There are a number of flashlights designed for rail mounting.

Method of Stadia (Range-finding)

In order to use your favorite exterior ballistics method you first need to know a number of things including the range to the target.
Most sporting telescopic sights do not include any rangefinder features and it's left to the spotter to determine range.
Most military telescopic sights include some form of ranging based on the method of stadia.
There are many types of Range Finders, a popular one is the laser range finder, but the good ones are expensive and can give away the shooter's position.

The Wiki page for angular mil really does not make it clear how it works.  The idea is that for very small angles the value of the sine of an angle (Wiki) is the same as the angle if the angle is expressed in radians (Wiki).  This comes about because of the Taylor expansion (Wiki) for the sine function.  So, if we say an angle is very small if it's 1/1000 of a circle.
So there are 1000 * 2 * PI milli radians in a circle (6283.185307....).
360 degrees / (2000* PI) = 0.057296... deg.
SIN(0.057296... deg) = 0.0010000000    That's a perfect ratio of 1 to 1000.
So... if you have two marks on a telescopic sight that are separated by 1 milli radian an object that's 1 yard tall will perfectly fit between the marks at a range of 1,000 yards.
If the object is 8" tall and fits a 1 milli radian angle it's range is 8,000 inches or 666.66 feet or 222.22 yards.

Note:  Minute of Angle (MOA) (Wiki) is a different thing.
A rule of thumb is that 1" at 100 Yards is a MOA.  Note: 100 Yards = 300 feet = 3600 inches.
Since a minute of angle is 1/60 of a degree and SIN(1/60) = 0.000291, and 3600" * SIN(1/60) = 1.047" the rule of thumb is close enough. 
This is also a very small angle but is different than an angular mill which would be 3.6" at 100 yards.
MOA is typically used to express the accuracy of a rifle whereas angular mils are used for range finding or aiming artillery.

SOPMOD M4 Accessory Kit

In the Wiki page for this kit there's an image showing a number of accessories and their name & NSN.
This is really about a variety of optical sights.

Nomenclature	Description	NSN	Link
M4A1	Carbine w/Carrying Handle	1005-01-382-0953
Reflex Sight	Trijicon, RX01M4A1, 1X24, Amber Reticle and Dot	1240-01-435-1916	eBay-Trijicon, Wiki 5653034 Reflex Sight 20040047586 R.S. mult pwr sources
ECOS-N	Aimpoint CompM2 (M68 Close Combat Optic))	1240-01-495-1385	Wiki,
	Trijicon acog 4x32, 4X Day Optical Scope	1240-01-412-6608	eBay 7676137 Optical sight 8364002  ACOG
AN/PEQ-5	Insight, Carbine Visible Laser	5860-01-439-5409	Wiki,
AN/PEQ-2	Infrared Illuminator	5855-01-422-5253	L3, Wiki
AN/PVS-17A	Mini Night Vision Sight (replaces the PVS-4)	5855-01-474-8904	eBay, Optics4Birding
	Backup Iron Sight	1005-01-449-6306
PVS14 (Wiki) PVS18 M68	Universal Pocketscope Mount	5855-01-482-6164 5855-01-485-7749 5855-01-465-7755
	Forward Handgrip	1005-01-416-1091
	Visible Bright Light Surefire M952NXM07 Millennium	5855-01-501-3081	eBay, Surefire, KM3 LED
	Sound Suppressor Kit	1005-01-437-0324	patent 6595099 ?
	Rail Interface System	1005-01-416-1089
M203 (Wiki)	9" (40mm) Barrel Assembly	1010-01-410-7422	eBay,
	40mm Grenade Launcher Sight	1010-01-418-4588
AN/PSQ-18A	M203 Day/Night Sight (DNS)	1010-01-516-0953	eBay,

M320 Grenade Launcher Module (Wiki) - to replace the M203
M26 Modular Accessory Shotgun System (MASS) (Wiki) - Option instead of the M203 or M320 - 5 shot pump 12 ga shotgun.
Probably based on the C-More Systems CMC-M1 straight pull 12ga clip feed shotgun.

Close Quarters Battle Receiver (Wiki CQBR) & close quarter combat (Wiki)
7325354 Weapon aiming device, Richard P. Grauslys, Allen R. Harding, Insight Technology, Feb 5, 2008, 42/131, 42/123 -
corrects many of the problems with the red dot sight.

A subset of Sights (Wiki) are Optical Sights, which include:

Telescopic (Wiki) - A telescope with adjustable cross hairs.  Parallax compensation (Wiki) for more accuracy
                                To test for parallax move eye left <-> right and see if reticle stays fixed relative to target.
                                Surveyors do this as part of the procedure of adjusting the eyepiece focus on the reticle.
                                737872 Gun-sight telescope, George N Saegmuller, Mar 17, 1903, 359/421 -
Reflector (Reflex) Sight (Wiki). The heads up display (Wiki) is based on the reflex sight developed in W.W.II., now thery are in cars (Wiki).
   PSS                            Included are Red Dot sights (Wiki) and Gyro (Gyroscopes) sights (Wiki)
                               PS a big problem with the original Red Dot was that the small coin cell battery would be quickly drained if you forgot to turn it off.
                               4330706 Photocell controlled power supply circuit for an LED, Aimpoint Ab, May 18, 1982, 250/214.0AL, 250/208.4
                               The CompM2 (M68/CCO) has been replaced by the CompM4 (Wiki)
                               Howard Grubb (1844 - 1933) Wiki: Optical work: Reflex sight & periscope
                               Victorian Telescope Makers: The Lives & Letters of Thomas & Howard Grubb by I.G. Glass, 1997
Collimator sight (Wiki) - the cross hairs appear to be at infinity, common on mortars and filed guns.
                                    The Bindon aiming concept (Wiki: BAC)) has been incorporated in the Advanced Combat Optical Gunsight
                                    (Wiki: ACOG) and combines reflex and collimator sights.
                                    4806007 Optical gun sight, Glyn A. J. Bindon, (Armson, Inc., Trijcon), Feb 21, 1989, 359/424, 42/122, 359/429, 359/431
Holographic Sight (Wiki) - uses a laser diode to illuminate a hologram in a reflex sight type housing.
                                    4012150 Holographic light line sight, Juris Upatnieks, Environmental Research Institute Of Michigan (EO Tech), Mar 15, 1977, 356/247, 89/41.06, 359/32, 89/41.19, 359/15
                                    Holographic weapons sight as a Crew Optical Alignment Sight - NASA  - the COAS is a collimator type sight                                  

Add On Optics - Note that the light coming into the front of all the above sights is collimated (Wiki) and so an optical accessory can be placed on the Picatinny rail (Wiki) and if it's output is also collimated will work with the sight.  For example a night vision adapter.  In a similar fashion an optical device can be placed behind sights that have collimated outputs, like the reflex and collimator sights.  For example a low power telescope.  Note for this type of add-on optic to work the output optical centerline of the front device needs to be the same as the input optical centerline of the rear device.  This might happen because the manufacturer of both devices made them to work together or because a height adapter is used (just an idea).

So in these cases the Picatinny rail is working as an Optical Bench (Wiki).

High Standard 10B Shotgun

A few decades ago I had one of these and today saw a YouTube video about it where the inventor's name was mentioned, so here's the patent:
2970398 Mechanism to enable firing of shotgun with one arm, Alfred H. Crouch, Feb 7, 1961, 42/69.1, 42/106, 42/72, 42/70.6, D22/103, 89/4.5, 89/1.42, 42/41, 42/73, -
Forgotten Weapons: High Standard 10B: Disassembly and Attempted Shooting  - loose pin in trigger group caused malfunction.

Interesting 22LR

The FN FAL with the K&K 22 sub caliber adapter above is my most interesting 22 gun.  There were different versions that utilized .22 Hornet or 22LR on the top barrel and .45 Colt/.410 shotgun on the bottom barrel.

The M6 Aircrew Survival Weapon (Wiki) aka Springfield Armory M6 Scout (Wiki) looks very interesting. YouTube: Forgotten Weapons - M6

This 2012 YouTube "5 Awesome .22 LR Firearms" mentioned the following:
Ruger 10/22 rifle rotary magazine semi auto (Wiki) - What ammo is he shooting at 1:04? - there is a take down version

3239959 Removable magazine for repeating gun, Mcclenahan Douglas S, Sefried Harry H, Sturm Ruger & Co, Mar 15, 1966 - 10/22 10-shot mag  

Marlin Model 60 tubular magazine semi auto - maybe the most popular 22 rifle made prior to the Ruger 10/22.
Ruger SR22 Pistol -I like the prior Mk IV semi auto pistol that has a long history of plinking fun.

D164735 Pistol, William B. Ruger, Sturm, Ruger Co. Oct 2, 1951, - The Mk I 22 pistol
2585275 Receiver and grip connection for autoloading pistols, Ruger William B, Sturm Ruger & Co, Feb 12, 1952 - The Mk I 22 pistol
2624969 Breech block and firing pin assembly for small arms, Ruger William B, Sturm Ruger & Co, Jan 13, 1953 -The Mk I 22 pistol   
2655839 Blowback autoloading pistol, Ruger William B, Sturm Ruger & Co, Oct 20, 1953 - The Mk I 22 pistol
2933983 Semi-automatic pistol, Ruger William B, Sturm Ruger & Co, Apr 26, 1960 -

CZ 452 bolt action - they mention the "Trainer" as having the look and feel of a 308 rifle.
Savage Mk II  bolt action rifle  adjustable trigger
GSG STG-44 a 22 rifle with the look and feel of the MP-44. fires only 22LR High Velocity ammo.

This YouTube "Top 5 .22 Takedown Rifles" mentioned the following:
Winchester 1890 led to the Winchester 62 (Wiki) - called Gallery Guns (Wiki) because of their use in shooting galleries firing 22 short or CB cap ammo.  I remember shooting these at the Santa Cruz beach boardwalk.

261667 Magazine Firearm, J.M. & M.S. Browning, July, 25, 1882, 42/17 -Winchester model 1890 tubular magazine pump action

Browning SA-22 Take Down (Wiki) - tubular magazine semi auto load magazine through port in stock.  My uncle had one of these and it had a very nice feel.

1065341 Take-down construction for firearms, John M Browning, Jun 24, 1913, 42/75.2, 42/1.7 - uses interrupted threads between barrel and receiver so only a quarter turn is needed 

Henry AR-7 Survival Rifle (based on ArmaLite AR-7 (Wiki)) - Stock holds receiver-barrel and clips with the butt cap as a lid.  I had one of these and while it may be practical seems cheap.  Based on the Armalite AR-1 bolt action .22 Hornet
Marlin 70PSS Papoose take down - based on the Marlin Model 60 (see above) - 22LR only in clip magazine - host to build suppressed 22
Ruger 10/22 Takedown - Sparrow Silencer 7856914 Noise suppressor, Jonathon Shults, Steven Michael Pappas, Silencerco, Llc, Dec 28, 2010 - ATI kit for 1-/22 take down  -
Chiappa little badger - seems cheap

Kel-Tec

KSG Shotgun - Bull Pup (Wiki) with two 6 round magazines (I used to have a High Standard 10B (Wiki)
8819976 Tubular magazine firearm with sheet metal receiver, George Kellgren, Kel-Tec Cnc Industries, Inc., Sep 2, 2014, 42/6, 42/75.03

page created 7 July 2010.