M14 Rifle History and Development By Lee Emerson Preface



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Part 2 Notes

1. Duff, Scott A. and CWO John M. Miller. p. 14 and Poyer, Joe. p 20. Ownership of the company changed in November, 1974 according to Duff and October, 1974 according to Poyer. A search for “M1A” on the U. S. Patent and Trademark Office web site shows that the name has been used in commerce since November, 1974. Mr. Ballance agreed that the sale to Bob Reese occurred during the fall of 1974 (author’s October 08, 2004 telephone interview).

2. Smith, Ron. Personal discussion. April 09, 2004.

3. Smith, Ron. Personal discussion. April 09, 2004.

4. Poyer, Joe. p. 25.

5. Stevens, R. Blake and Edward C. Ezell. The Black Rifle M16 Retrospective. Collector Grade Publications: Cobourg, Ontario, Canada, 1994. p. 327.

6. Ibid, p. 328.

7. Poyer, Joe. p. 25

8. Stevens, R. Blake and Edward C. Ezell. p. 327.

9. Smith, Ron. Personal discussion. April 09, 2004.
Part 3

All Things Small and Wonderful
M14 Barrel Material

Typically, M14 type rifle barrels are made of AISI 4140 alloy or AISI 416 stainless steel. While much has been written discussing the merits of molybdenum-chromium versus stainless steel for barrels the best evidence seems to indicate that both are equal in accuracy with throat erosion occurring slightly faster in the stainless steel barrels. The advantage of the stainless steel barrel is better corrosion resistance.

General Information On AISI 4140 Alloy Steel

The following information on AISI 4140 alloy steel is presented as background information. It is a medium carbon molybdenum-chromium alloy steel. Its composition, physical properties and description are as follows:

Carbon 0.38 to 0.43 %

Chromium 0.8 to 1.1 %

Manganese 0.75 to 1.0 %

Molybdenum 0.15 to 0.25 %

Phosphorous 0.035 % maximum

Silicon 0.15 to 0.35 %

Sulfur 0.04 % maximum

Density – 0.28 lb/cu in

Specific Gravity – 7.83

Specific Heat – 0.114 BTU/lb/deg F

Melting Point – 2580 degrees F

Thermal Conductivity – 159.5 BTU-in/ft2-h-deg F

Mean Coefficient of Thermal Expansion – 7

Modulus of Elasticity Tension – 33

Typical Uses – This is a very common alloy steel. It is used to manufacture gears, axles, connecting rods, hand tools, etc.

Features - Toughness, good ductility and good torsional and fatigue strength

Machinability – Average surface cutting speed is 110 feet per minute. The machinability rating is 66 % of AISI 1112 in the annealed condition.

Forming – Good in the annealed condition

Normalizing – Typically heated at 1675 degrees Fahrenheit for sufficient time to ensure thorough heating then allowed to air cool

Hardening – This alloy can be hardened by 1) normalizing by heating to 1550 Fahrenheit then oil quenching then tempering or 2) annealing then cold working.

Annealing – Heat to 1600 degrees F then slowly cool in the furnace.

Forging – Forging is performed from 2200 degrees to 1750 degrees F.

Tempering – The steel is heated at temperatures ranges from 400 to 1200 degrees F depending on the hardness wanted. The lower the tempering temperature the higher the hardness and tensile strength. For example, AISI 4140 steel that is oil quenched then tempered to 1300 degrees Fahrenheit has an ultimate tensile strength of 118,000 psi. The same steel that is oil quenched and tempered to 700 degrees Fahrenheit has an ultimate tensile strength of 231,000 psi.

General Information On AISI 416 Stainless Steel

The information on AISI 416 stainless steel is presented for the benefit of the reader. AISI 416 is a martensitic stainless steel. Its composition, physical properties and description are as follows:

Iron – major element

Chromium - 13 %

Manganese - 1.25 % maximum

Silicon - 1.0 % maximum

Molybdenum - 0.6 % maximum

Carbon - 0.15 % maximum

Sulfur - 0.15 % minimum

Phosphorous - 0.06 % maximum

Density – 0.28 lb/cu in

Specific Gravity – 7.7

Specific Heat – 0.11 BTU/lb/deg F

Melting Point – 2714 degrees Fahrenheit

Thermal Conductivity – 172.6 BTU-in/ft2-h-deg F

Modulus of Elasticity Tension – 29

Typical Uses – Valve parts, pump shafts, bolts and nuts, gears, electric motor shafts, gears

Features – Very good corrosion resistance, good strength, excellent machinability, poor weldability and magnetic in all conditions

Machinability – The machinability rating is 85 % of AISI 1112 steel. This alloy was the first free machining stainless steel developed. It has the highest machinability of any common stainless steel.

Hardening – This alloy can be hardened by heating between 1700 and 1850 degrees Fahrenheit, quenching in oil and tempering. This process first produces 100 % austenite structure followed by formation of martensite.

Annealing – For a full anneal, heat AISI 416 stainless steel to between 1500 and 1650 degrees Fahrenheit for thirty minutes per inch of thickness. Cool the steel at a maximum rate of 86 degrees Fahrenheit per hour to 1112 degrees Fahrenheit then air cool.

Tempering – First heat the steel to obtain the hardness and strength wanted. A lower tempering temperature results in higher hardness and tensile strength, while higher tempering temperatures produce lower hardness and tensile strength. When AISI 416 stainless steel is heated, oil quenched and then tempered to 1202 degrees Fahrenheit, it will have an ultimate tensile strength of 109,000 psi and a hardness of 20 HRC. The same steel that is heated, oil quenched and tempered to 399 degrees Fahrenheit has an ultimate tensile strength of 194,000 psi and a hardness of 41 HRC. Industry practice is to avoid tempering this alloy between 750 and 1076 degrees Fahrenheit because poor toughness and corrosion resistance results.

The Barrel Making Process

Barrel making is a centuries old process. Some steps in the process may not be performed in the order described herein, depending upon the method of rifling employed. To make a rifle barrel, a hole is drilled through the center of a piece of round bar stock using a gun drill. The hole is then reamed if it will be cut or button rifled or it is honed if it will be hammer forged. Reaming and honing improve the bore finish and make the interior diameter more consistent. The barrel blank is then rifled. Rifling forms the lands and grooves of the barrel at the desired twist rate.

Rifling is performed using one of three methods: 1) cut 2) button and 3) hammer forging. Cut rifling uses a cutter to form the barrel grooves. Krieger and Obermeyer make their barrels by the single point cut method, with the tool cutting in only one groove at a time. USGI National Match M14 barrels were produced by the broach cut method. Button rifling involves pushing or pulling a button with lands through the blank to form the grooves of the barrel. Barrel makers such as Douglas, Hart, Shilen and Wilson Arms use the button rifling method. In hammer forging, the barrel blank starts off shorter than the finished length. The blank has a mandrel passed down the bore then it is pounded on the exterior by opposing hammers. The barrel blank is squeezed off the mandrel and cut to the desired length. TRW made chromium plated USGI M14 barrels by the hammer forging method.

After rifling, the barrel blank will usually be stress relieved. Stress relieving can be done by heat treatment or cryogenics. When drilling removes material from the bore, stresses build up inside the barrel’s remaining material. If this stress is not relieved, the barrel blank can bend during the next step in the process. After stress relief, the barrel blank exterior contour is formed by turning it on a profile lathe. The last major metalworking step is lapping. This is done to polish the bore, remove machining marks, and achieve the desired dimensional consistency. The barrel is stamped as desired by the maker then blued or phosphate coated if made of molybdenum-chromium alloy steel. Finished rifle barrel hardness is typically 25 to 32 HRC. This leaves the barrel strong enough to handle the chamber pressure with a comfortable safety factor yet tough enough to resist substantial impact.

Winchester used the following procedure to make USGI M14 barrels. Re-sulphurized AISI 4150 molybdenum-chromium alloy steel was hot extruded and sheared into barrel blanks. The barrel blanks were furnace heated and oil quenched with a twenty minute cycle time for the heat treatment. Next, the barrel blank was machined by drilling the bore then turning the exterior contour by four passes on lathes. The barrel was then prepared for chromium plating by electro-polishing the bore. The chromium plating was then applied. The chromium plating was applied 0.0015 " thick at the breech end of the rifling, with the plating thickness intentionally tapered very slightly to a thickness of 0.001 " at the muzzle. The final step was phosphate coating. USGI chromium plated M14 barrels weigh 31.7 ounces and were designed for a minimum service life of 15,000 rounds. The USGI M14 chromium plated barrels have a maximum rate of fire listed in both editions of FM 23-8.

M14 Barrel Length

The following is a list of standard barrel lengths for the M14 type rifle. Troy Industries has installed barrels less than 16.5 " on its Rock SOPMOD M14 carbine upon special request (all NFA rules apply).

22 " - USGI National Match, commercial match grade, and USGI, Chinese, and Taiwanese chromium plated barrels

18.5 " - Bush barrel sold by Fulton Armory

18 " - Springfield Armory, Inc. M1A Bush and Scout Squad

17 5/8 " - Smith Enterprise, Inc. Bush Barrel conversion and Chinese Bush barrels

16.5 " - Troy Industries Rock SOPMOD M14

16.25 " - Springfield Armory, Inc. M1A SOCOM 16

13.5 " - Smith Enterprise, Inc. M14K

USGI M14 Rack Grade Barrels

Military service barrels are made of molybdenum-chromium alloy steel. M14 rack grade barrels are chromium plated, standard (lightweight) contour and have a 1:12 twist rate. There were several contractors for USGI M14 chromium plated barrels such as H&R, TRW, Winchester, Springfield Armory, and Saco-Lowell. TRW made chromium plated M14 barrels until at least May, 1964, Harrington & Richardson until at least February, 1963, Springfield Armory until at least October, 1967, Winchester until at least May, 1964 and Saco-Lowell / General Dynamics until at least February, 1983.

Chromium plating of barrel chambers and bores increases barrel life, improves sustained fire capability, enhances corrosion resistance and makes cleaning easier. The chromium plated chamber aids extraction and allows the rifle to function when fouled with firing residue and dust. The disadvantage of a chromium plated bore is a slight loss of accuracy as compared to a non-plated bore. The loss of accuracy is not an amount the average shooter would notice.

A typical USGI M14 barrel marking is as follows: H R 7790190 1 63 AK. H R is the manufacturer, Harrington & Richardson. 7790190 is the USGI drawing number for the M14 chromium plated barrel. 1 63 is the month and year of manufacture, January, 1963. AK is the heat lot code for this particular barrel.

USGI M14 National Match Barrels

USGI match grade M14 barrels were made to stricter dimensional standards than the rack grade barrels. Gene Barnett (using Douglas Premium blanks), Canadian Arsenals, Harris Graphics, Hart, Krieger, Mike Rock Rifle Barrels, Nomura Machine, Saco-Lowell, SGW, Springfield Armory, and TRW made National Match GI barrels. TRW made National Match M14 barrels until at least April, 1966 as well as Canadian Arsenals until at least June, 1983. Saco-Lowell National Match M14 barrel markings indicate dates of manufacture from at least July, 1965 until June, 1985. Gene Barnett has supplied the U. S. Marine Corps and U. S. Army National Guard with M14 National Match barrels since at least the early 1980s.

Dates of production observed for SGW lightweight match barrels extend from July, 1982 through November, 1982. More than 1,200 of these barrels were produced. Its government contract required SGW to use steel from a particular vendor. SGW manufactured the barrels and delivered them to Rock Island Arsenal for assembly on M14 NM rifles. At that point, Rock Island Arsenal found the properties of this lot of steel to be inconsistent. This was the fault of the steel supplier and not SGW. The U. S. Government canceled the contract and returned the barrels to SGW. SGW then tested all the barrels for proper hardness. Those that passed testing were remarked OLY and sold. These OLY marked broach cut match grade barrels give excellent accuracy and service.

Nomura Machine made M14 medium weight National Match barrels in 1992. Likewise, New Arc Welding and Steel made heavy weight National Match barrels the same year. Saco-Lowell made both lightweight (standard) and medium weight contour National Match M14 barrels. Mike Rock Rifle Barrels, Inc. M14 barrels were madein 1994 and 1995 for the U. S. Marine Corps. The gas system was moved forward 0.035 ” on these heavyweight barrels to increase the dwell time so that 190 grain bullets could be used in competition. Canadian Arsenals, Harris Graphics, Springfield Armory and TRW manufactured National Match barrels in the standard contour.

The USGI National Match barrels for the most part used a 1:12 twist. One exception was several Lackland AFB U. S. Air Force-built M14 NM rifles which were rebuilt by Ted Brown in the past for the Oregon Air National Guard. These Barnett barrels had a twist rate of 1:10 and were stamped USAF on the right side of the chamber. The NSN for the M14 lightweight National Match barrel is 1005-00-018-3255. The NSN for the medium weight National Match barrel is 1005-01-272-0970. A USGI contract M14 National Match barrel that has passed all quality assurance inspections will be stamped NM near the muzzle. Typically, match grade M14 type rifle barrels begin to lose competition level accuracy after 5000 to 9000 rounds depending on use and cleaning regimen. The approximate weight for a medium weight M14 barrel is 38 ounces and 57 ounces for a heavyweight M14 barrel.

Chinese M14 Barrels

Chinese barrels are lightweight (standard) contour chromium plated barrels. The quality of Chinese barrels is generally very good and the chromium plating is well done. The Chinese have extensive experience in chromium plating parts because of manufacturing AK type and SKS rifles. Chinese barrels are chambered for 7.62x51 mm NATO ammunition. Shooters have obtained 1 ” groups with Chinese barrels.

U. S. Commercial M14 Barrels

Commercial and match barrel makers include Citadel, Criterion, Douglas, Hart, Krieger, Obermeyer, Shilen and Wilson Arms. Douglas Barrels, Inc. (Charleston, WV) has been manufacturing rifle barrels for over fifty years. Krieger Barrels, Inc. (Richfield, WI) was established in 1982. Krieger Barrels and Obermeyer produce excellent quality custom barrels. Krieger Barrels, Inc. made M82A1 .50 BMG barrels for the U. S. military during the First Gulf War. In 1999, Krieger formed another company, Criterion Barrels, to make rifle barrels for manufacturers. U. S. match grade and most commercial barrels are not chromium plated. Barrel makers, such as Douglas and Krieger, offer M14 type barrels in different twist rates and choice of molybdenum-chromium or stainless steel. The standard twist rates are 1:10, 1:11 or 1:12. Troy Industries installs a 1:11.27 twist barrel for its Rock SOPMOD M14 conversion. Commercial match barrels will be medium weight or heavyweight. 1:10 twist barrels are better for stabilizing heavier bullets, e.g., 168 grain Sierra HPBT Match. The commercial manufacturers listed above all produce high quality M14 barrels.

In November, 2003 Fulton Armory began selling chromium plated and non-plated commercial manufacture standard contour M14 barrels. Lightweight (standard contour) and medium weight M14 barrels sold by Fulton Armory are made to its specifications and come with a limited lifetime warranty on materials and workmanship. Beginning in late 2003, Fulton Armory barrels marked C.B.F.A. are supplied to them by Criterion Barrels, Inc. Similarly, LRB Arms is selling Wilson Arms chromium plated and non-plated standard contour M14 barrels as of May, 2004. Later that same year, LRB Arms began to offer Criterion 18 " chromium plated and non-plated standard contour barrels.

Smith Enterprise, Inc. will be supplied with barrels from Wilson Arms for M14K rifles and to fulfill a 2004 request from the Philippine Government for 1400 M14 barrels. The barrels will be made to Ron Smith’s specification. This specification requires the barrel to be 22 ” long, four groove standard (lightweight) contour with a 1:10 twist rate and 7.62 mm Navy chamber. The 7.62 mm Navy chamber is sized for heavier bullets. Some will be chromium plated and some will not.

USGI M14 Wood Stocks

Background Information – The information on cherry, yellow birch and black walnut is presented below for the benefit of the reader.

Cherry (Prunus serotina)

Description – The heartwood color varies from red to reddish-brown to deep red. There may be brown flecks in the heartwood. The sapwood is colored creamy white to creamy pink to reddish brown. Cherry has a fine, straight grain and a smooth texture.

Common Uses – Furniture, cabinets, flooring, boat interiors, and others. It is an excellent wood for carving and lathe turning.

Durability – Cherry is moderately durable. The heartwood is moderately resistant to preservative treatment. The sapwood is susceptible to attack by the furniture beetle.

Weight – 36 lb/cu ft

Specific Gravity – 0.54

Hardness – 660 on the Janka Hardness scale

Stiffness 1,655,000 psi

Bending Strength - 13,520 psi

Shearing Strength – 1,700 psi

Maximum Crushing Strength – 7,865 psi

Yellow Birch (Betula alleghaniensis)

Description – The heartwood color is light brown to reddish brown. The sapwood is colored light red brown or light yellow. Yellow birch has straight, close grain and a fine, even texture.

Common Uses – Furniture, high grade flooring and plywood, upholstery frames among others

Durability – Yellow birch is perishable and susceptible to attack by the furniture beetle. The heartwood is moderately resistant to preservative treatment. The sapwood is permeable.

Weight – 43 lb/cu ft

Specific Gravity – 0.62

Hardness – 1260 on the Janka Hardness scale

Stiffness – 2,010,000 psi

Bending Strength – 16,600 psi

Shearing Strength – 1,880 psi

Maximum Crushing Strength – 8,170 psi

Black Walnut (Juglans nigra)

Description – The heartwood color is light gray brown to chocolate brown to purple-black brown. The sapwood is colored creamy white to yellow brown. Black walnut has a straight grain typically but the grain can be wavy or curly. Its texture is coarse. Walnut can be steamed to make the sapwood darker and the heartwood lighter which allows more of the tree to be used. Steaming is done for aesthetic purposes and does not otherwise change the properties of walnut.

Common Uses – Gunstocks, furniture, cabinets, musical instruments, and other uses. It is an excellent wood for carving and lathe turning.

Durability – Black walnut is very durable. The sapwood is susceptible to attack by the powder post beetle. The heartwood is resistant to preservative treatment and biodegradation.

Weight – 40 lb/cu ft

Specific Gravity – 0.59

Hardness – 1010 on the Janka Hardness scale

Stiffness - 1,790,000 psi

Bending Strength – 14,800 psi

Shearing Strength – 1,370 psi

Maximum Crushing Strength – 7,680 psi

USGI Wood Stock Production - Springfield Armory, Harrington & Richardson, and Winchester made wood stocks for their USGI M14 rifles. Frank Overton was the owner of S. C. Overton & Co. (South Haven,MI). This company was the largest employer in South Haven, MI when it went out of business in 1990. From World War II until 1990, S. C. Overton & Co. produced M1 Carbine, M1 Garand and M14 stocks and M1 Garand hand guards. It was the exclusive supplier to TRW for walnut and birch M14 stocks. Early S. C. Overton & Co. M14 stocks were made from black walnut but most were made from birch harvested from a single forest in Maine near the Canadian border. The black walnut wood came from the U. S. Government stockpile. The wood was shipped at government expense to S. C. Overton and formed on government owned stock making machinery operated by S. C. Overton & Co. employees. The automatically operated multi-station machines performed all woodworking operations except the finish sanding. The production rate for these machines was 400 stocks per hour. The M14 stock making machinery was converted around 1971 or 1972 to produce M1 Garand stocks for a new government contract. S. C. Overton & Co. was still producing M1 Garand stocks and inventoried contract over run M14 stocks when it closed down in 1990. Sykes Manufacturing made replacement M14 stocks for Springfield Armory.

The first M14 stocks were made of black walnut. Beginning in 1961, yellow birch was the standard wood with black walnut as the alternate. Some wood USGI stocks have a raised shelf at the base of the trigger group inletting. Ferrules, the piece of metal at the very front end of the stock, on wood USGI stocks are either dimpled (round punch mark on the sides) or crimped (half-moon indentation on both sides). Standard size wood stocks were made from 1959 to 1963. In contrast with the high degree of automation in all other production processes for the M14 rifle, the USGI wood stock makers all hand sanded every stock one at a time with a rotary sander. This was done to smooth the stock and ensure that all surfaces were true and all corners sharp.

USGI Wood Stock Markings – USGI manufacturers' markings were stamped in the butt end of the wood stocks as follows: H for Harrington & Richardson, O for S. C. Overton & Co., S A for Springfield Armory, S A inside a diamond for Sykes Manufacturing and W-W for Winchester. It may be necessary to remove the butt plate to see the manufacturer stamping.

Wood stocks were marked with a DOD cartouche, also referred to as a Defense acceptance stamp, on the left side near the receiver and a proof mark on the underside of the grip if they passed final ordnance inspection and proof firing, respectively. A DOD cartouche inside a circle on the left side of the butt stock near the rear sling swivel has been observed on a small number of USGI wood stocks. The proof firing stamping is a 5/16 ” high letter P inside a ½ ” diameter circle that is stamped on the stock on the forward side of the grip. There appear to be two types of letter P proof marks, one with a serif font P and the other with a sans serif or Arial-style P. The proof firing marking appeared on U. S. military rifles from 1873 until the end of M14 production. Most replacement USGI wood stocks will not have the proof P and DOD cartouche markings. Replacement stocks from Springfield Armory, however, were stamped with the DOD cartouche.

Before final assembly, each wood stock was dipped in tung oil. The walnut stocks were dipped twice but the birch stocks only once. It was found during the first half of 1962 that two coats of oil left excessive oil and residue on the birch stocks due to that wood’s different grain characteristics and slower absorption of oil as compared to walnut. Consequently, the procedure was changed to one coat of oil for birch stocks. Commercial producers of the USGI M14 rifle sprayed a stain on the birch stocks prior to the dipping in oil. This produced a color very close to that of black walnut. After several days of draining and drying, sample stocks were tested for resistance to smoke and water before the rest of the lot was approved for oil treatment and final assembly. The last M14 rifles assembled with wood stocks left the manufacturers in July, 1963. Birch stocks are stronger and harder than walnut stocks. Walnut is about 10 % lighter than birch. Some beech and a few cherry stocks were made as well.

Oversized walnut, birch and laminated wood stocks were made for match grade M14 rifles. Solid wood USGI stocks are sought after for the appearance and historical authenticity. However, solid wood tends to swell or contract with changes in ambient temperature and humidity. At some point, someone came up with the idea of gluing layers of wood together to create a rough form that could be worked into a finished rifle stock. This composition of wood and glue is very strong and resistant to impact. Laminated wood stocks are slightly heavier than solid wood stocks but they are more resistant to temperature and humidity fluctuations. They can be bedded just like solid wood stocks.

Reinhart Fajen began making wood gun stocks in the 1950s at a facility in Warsaw, MO. His craftsmanship earned a well-deserved reputation among hunters. Later on, Reinhart Fajen, Inc. purchased Bishop Stocks and grew rapidly. Reinhart Fajen produced factory issue stocks for rifle manufacturers such as Sturm, Ruger & Co. and Savage Arms Company. Reinhart Fajen, Inc. made USGI M14 stocks about 1990 for the First Gulf War. It made three styles of M14 stocks in two materials, walnut and laminated wood. Style I was the USGI standard contour and Style III was the oversized National Match stock (NSN 1005-01-233-8635). Later-manufacture oversized National Match stocks do not have stock liners. They were made to be bedded and have been routed for the rear lug. The M14 stocks supplied to the U. S. Government for the First Gulf War were shipped to Rock Island Arsenal for cutting the selector cutout, preserving and packing before stocking in the DOD supply system.

Unfortunately, Mr. Fajen passed away in the mid-1990s and the company struggled thereafter. Reinhart Fajen, Inc. was then acquired by the Potterfield Group. The Potterfield family made a valiant but unsuccessful attempt to turn a profit from the Reinhart Fajen plant in Lincoln, MO. Consequently, plant operations were suspended in Lincoln, MO by the fall of 1998. Production of stocks for other rifles was then contracted out to several companies around the United States using proprietary CNC software programs. The equipment and inventory was sold off. Boyd’s' bought the stock inletting equipment from Reinhart Fajen, Inc. Springfield Armory, Inc. bought half of the remaining inventory of M14 stocks and Midway USA purchased the remainder. All of the stocks, including the M14 models, quickly sold out once it was known that the Lincoln, MO plant had ceased operating. Springfield Armory, Inc. installed stocks made by Reinhart Fajen, Inc. on M1A rifles until at least January, 1999. As of 2004, Battenfeld Technologies, Inc. continues manufacturing this line of stocks for rifles other than the M14 type.



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