M1919  History
Barrels and Jackets
Bottom Plates
Top Covers
Bolt Latch
Top Plates and Latches
Back Plates/Buffers
Front & Rear Sights
Barrel Extension
Lock Frame
Boosters and Flashhiders
Publications for Sale

                                                       THE M1919A5


The M1919A5, Fixed, Caliber .30 air cooled Browning machine gun, Major Item 51-114, was a special purpose design that was intended to replace the M1919A4 Fixed model in certain armored vehicle applications. 

In the late 1930's and early 1940's the U.S. Army's concept of armored warfare was not well aligned with reality.

Most U.S. armored tactics had evolved based on the limited experience gained in WWI along with some theorizing about the use of armored forces in the screening, scouting and raiding traditions of the Cavalry.

Light tanks like the various models of M2 and M3 Stewart with their 37mm main gun were to be employed as scouts and infantry support. 

Medium tanks like the M4 Sherman with its 75mm and later 76mm main gun were intended to be used as Infantry support. 

To counter enemy armor "Tank Destroyer" units which mounted various weapons up to 90 mm on tracked vehicles were supposed to be the answer.

The big problem with this concept was that the German armored doctrine was not based on the U.S. theory of how they were supposed to operate. 

Light tanks while fast, were just too lightly armed and armored to be effective and the medium tanks were not designed to go toe to toe with German armor that accompanied either mechanized (Panzer) or conventional infantry units. 

Contrary to popular opinion about so called "Blitzkrieg" warfare the WWII German ground forces were only about 50% mechanized, many conventional infantry divisions made extensive use of draft animals. 

By contrast U.S. forces used few draft animals except for unusual circumstances like mountainous regions of Italy and on Pacific islands like New Guinea.   

The biggest drawback to Tank Destroyer concept was they were never where you needed them and because they had open top turrets the crew was vulnerable to air burst artillery.

Eventually they were relegated to roles in the ETO as self propelled direct fire artillery used for infantry support and capable of engaging enemy armor if it happened to appear.

After 1943 the entire Tank Destroyer concept was scrapped and units still undergoing training in the U.S. were converted to Amphibious Tractor Battalions and mostly used for island invasions in the Pacific Theater. 

In the mid and late 1930's when the M1919A4 design was being readied for mass production it was decided to produce both a Fixed and a Flexible model, and separate Major Item numbers were assigned to each version. 

The M1919A4 Fixed model differed from the M1919A4 Flexible in only one respect, it used a back plate with a vertical buffer tube lacking a pistol grip that was adapted from the M1919 Browning Aircraft Machine Gun.

For a complete review of back plates please visit the "Back Plates/Buffers" tab on the Home page.

The M1919A4 Fixed model was installed in the M1, M2 and M3 tanks and other vehicles requiring a fixed style of mounting. 

Tanks mount machine guns in several fashions.

Most of us are familiar with with the trainable exterior mounting next to the hatch on the turret top.  It has a nearly 360 degree field of fire and it is useful as an anti-aircraft and anti-personnel weapon. 

The main drawback is that it requires the operator to be exposed to enemy fire.



Ball mountings, where the operator, usually the assistant driver or sometimes another crew member, operates this forward firing and hand aimed gun protected from enemy fire by the hull armor and the ball mounting. 

The picture above is an Ordnance Department photo of the Assistant Drivers position on a M4 (Sherman) medium tank from wwiivehicles.com.  The weapon shown appears to be a standard M1919A4 Flexible connected to the ball mount with a pin through the tripod mount adaptors. 

The rectangular container just below the A4 is the ammunition tray with the lid closed.

Most tanks also have a coaxial mounting where the machine gun is attached to a combination mount and is trained and fired by the gunner using the same training and elevation mechanism and aiming device as the main gun.

In WWII this aiming device was an optical sight either a telescope mounted with the main gun tube or a periscope mounted in the turret roof.  The main gun and coaxial machine gun were both bore sighted, the center of the bore of each weapon was aligned with 0 defection and 0 elevation marks (cross hairs) on the telescope.




This cut from TM 9-1078 M4A3 Medium Tank (1954) courtesy of Tom Chial shows the view through the M70F Telescope used to bore sight and "lay on" (aim) the weapons.

The range graduations, the short vertical dashes and spaces, are 200 yard increments from 0 (point blank) to 4200 yards. 

The dashes and spaces left and right are 5 mil increments of deflection. 

This telescope is graduated for the 75 mm M61 armor piercing round as noted at the top of the lens.

This TM has detailed instructions for bore sighting both weapons in the combination mount to both the M70F telescope and the gunners periscope.

The coaxial machine gun on an M4 tank could be fired manually or remotely by means of a solenoid. 

Tank development included gun mount development and in some instances, especially with the M2A4 and M3A1 Stewart light tanks using the newly developed gun mounts, the mounts lacked clearance necessary for retracting the bolt or even mounting the weapon. 

At first M1919A4 fixed weapons were modified to to work on those mounts lacking the required space.

After 3,000 or so weapons were modified Ordnance decided to make it official by assigning a "Standard" designation to the modified weapons, M1919A5.

Some parts and the basic design used to modify the M1919A4 and to build M1919A5 weapons from scratch were borrowed from the M1919 and M1918M1 Browning Aircraft Machine Guns. 

These "borrowed" parts included the cocking stud that replaced the A4 bolt handle, the bar guides, spacers and the plug, spring and plunger detent system that held the retracting bar in the forward position during firing. 

The M1919A5 back plate and horizontal buffer system was a modified version of the M1918M1 back plate and buffer system. 

The A4 top cover hold open feature using the spring, fixed and movable plates was replaced by the "Cover Detent Assembly" mounted on the left side.  This gave additional right side clearance.

The first obvious mention of the M1919A5 are changes to many of the part drawings common with the M1919A4 that add Major Item 51-114, the M1919A5, to the "Drawing Pertains To" block, the date of these revisions varies from 5-15-42 to 5-28-42.



This item from Ordnance Committee Meeting minutes explains why some M1919A5's  encountered have a rear sight bracket and are equipped with front sights and vertical buffers.  They started life as M1919A4 Fixed weapons and were converted before the M1919A5 designation was approved. 

These 3,000 or so weapons were likely marked M1919A4 until they went through a rebuilding process.

This is an Ordnance Department photo from wwiivehicles.com showing what could be be one of the modified M1919A4's referred to in the OCM Item 17705 mounted  on what the photo caption calls an "M44" combination gun mount with the 37 mm main gun installed in a M3A1 Stewart light tank

This photo shows the machine gun equipped with the vertical buffer back plate generally shown used on the M1919A4 Fixed weapon.  

As of this writing I have not been able to locate any documentation for an "M44" mount, but that does not mean it didn't exist.

The lack of right side clearance and the need for the rear operated bolt handle are obvious.  This weapon has no rear sight base making it either a M1919A4 Fixed with the rear sight base removed conversion or possibly a purpose built A5.

The firing solenoid is visible just below the trigger.


This photo is from SNL A-55 Section 6 dated 9-42, courtesy of the RIA Museum, Jodie Creen Wesemann, shows a right side view of what appears to be the same mount shown in the previous picture identified as an "M44", but this mount is positively identified as an M23. 

This is a clear view of the method of mounting the machine gun and the trigger solenoid along with the vertical buffer back plate which was usually seen on the M1919A4 Fixed.

The weapon pictured has neither front or rear sight and the original digital image did not show the rivet hole for the bolt latch that would be present if this weapon was originally a M1919A4 Fixed.

It should be noted that any of the three styles of fixed weapon back plates could be used on either the M1919A4 Fixed or the M1919A5 Fixed even though the A4 Fixed is usually pictured with the vertical buffer style and the A5 Fixed with the horizontal design.

I have not been able to figure out why Ordnance bothered to attach the "Fixed" identifier to the M1919A5 as it was not furnished in a Flexible model like the M1919A4. 

Seems a bit redundant.


Not all coaxial mounts required the extended bolt retracting slide and left side cover detent assembly.

This photo from TM 9-7018 M4A3 (Sherman) Medium Tank dated 9-54 courtesy of Tom Chial shows a coaxial mount using a standard M1919A4 Flexible.  The weapon is attached to the mount using the front mount adapter and the T&E bracket.

The two pronged fork just to the rear of the "Locking Pin Holes" is the support for the ammunition bag holder.

The first reference to the M1919A5  parts we have encountered is the September, 1943 SNL A-6, likely the parts were mentioned in the SNL A-6 dated September, 1942, however we have not been able to locate a copy of that SNL.  Both versions would list all of the parts specific to the A5.  However there is no illustrations of the parts until the issuance of ORD 9 SNL A-6 in April of 1947.

This cut from the 1947 SNL  shows all of the casing parts and the handle assembly usually referred to as the retracting bar or slide.


The caption on this photo dated February 9, 1942 plainly states that this is a M1919A5.  However, this date is only about two weeks after the OCM Memo establishing the M1919A5 designation. 

Here's a close-up of the side plate markings of the weapon pictured above. Both pictures courtesy of the RIA Museum Jodie Creen Wesemann show a M1919A5 fabricated from a New England Westinghouse Browning Aircraft Machine Gun that was likely a VERY early conversion to a M1919A4.

The big question here is, is this weapon a M1919A4 converted for use in tanks as mentioned in the OCM Memo before the establishment of the M1919A5 designation and RIA just remarked it A5 or is it a "real" M1919A5?  

My money is on the RIA just remarked so as to have an "example" of  the "new" M1919A5 theory.

Unfortunately, the exact model of Aircraft Gun has been pretty well obliterated, but the picture it gives a good view of the function of the stop pin and the plunger in the detent cut holding the retracting handle in the forward position.

The handle assembly had two different styles of "knobs" the early version had the familiar bell shaped handle shown in the previous pictures of the "M44" and M23 combination mounts. 

When the A4 bolt handle drawing changed to a straight or rod style handle in February 1943 this "handle", called a knob in the SNL, changed with it.

When the M1919A5 was introduced in May 1942 all air cooled Caliber .30 Browning machine guns were still required to be equipped with a bolt latch who's primary purpose was to prevent cook offs.

The A5 was no exception to the rule.

When the handle is pulled to the rear the front rectangular cut on the bottom of the retracting bar will engage the bottom of the rear guide and the spring loaded plunger in the rear guide that normally keeps the retracting bar when fully forward from flopping around during firing exerts enough downward pressure on the bar to hold the bolt to the rear. 

When the retracting bar is fully forward against the stop pin the plunger engages the half round cut on the top rear of the retracting bar preventing the bar from sliding to the rear from vibration and being jerked forward as the cocking stud reciprocates with the bolt during the firing cycle.

This retracting bar or "Handle Assembly" does not reciprocate like the A4 bolt handle when firing, rather, the cocking stud installed in the bolt in lieu the bolt handle moves back and forth.

The handle assembly is only used to retract the bolt to start the loading cycle or to clear a stoppage like the charging handle of the M16 rifle or the M1918A2 BAR.

To load the weapon the handle is pulled to the rear and released for the "half load" and pulled and released a second time for the "full load" just like the other M1919's being loaded with the top cover closed.


This cut, also from the April 1947 SNL shows the individual parts that make up the cover detent group.  Like most "exploded" drawings it is difficult to see exactly how the parts interact.

This drawing gives two views of the cover detent group parts and their relationship with the casing and top cover.  The bolt head doesn't stick out much farther then the mount adaptor on the bottom of the casing.

The note at the bottom indicates that this drawing superseded C74974 which is one of the drawings mentioned in the OCM Item 17705.

This is the original assembly drawing prepared by by RIA showing the details of the retracting handle and the stop pin which allowed the retracting bar to be properly positioned for the spring/plunger to hold the handle and prevent the assembly from being pulled too far forward by the bolt returning to battery.

Note the date, May 14, 1941, a year before the M1919A5 became a Standard Item and the information in the "Drg. Pertains To" block indicating that this part was originally intended for modifying M1919A4 Fixed weapons as mentioned in the OCM Item # 17705.

There are no authorizing signatures, and the assembly was supposed to be piece marked B170985.

The vertical note on the right margin is interpreted to mean that this assembly was intended to be used on Light Tank M2A4 & M3.

Revision 3 to drawing B170985 (2-25-43) changed the style of the "knob" to the rod style note that imprinting the piece mark on the retracting bar is no longer required.

The rod style "knob" and the bell style are nearly identical to the standard A4 bolt handles except for the length of the shaft.



Drawing C90722 Revision 2 (1-27-43) is the M1919A5 right side plate assembly drawing showing guides and spacers, note that there is no provision for the rivet used to mount a bolt latch like the M1919A4 fixed model as the retracting handle serves the same function.

The guides and spacers are riveted to the side plate, later most M37's used bolts and safety wires to attach the guides to the side plate.

This assembly drawing does not show the spring loaded plunger that holds the slide in position.

This Draftsman's Work Order is what changed the design of the knob from bell shaped to rod style.  Note that there is no reference to "O.O." letters of authorization for the change, just a telephone conversion between two rather junior Ordnance officers, one in the Chief of Ordnance's office and one at RIA.

This change in design was to be implemented at the discretion of the manufacturer (along with the Ordnance District supervising the contract) in a way that was to avoid increased cost to the government.

This wording or similar notations appear on many design changes, which may explain why  some changes were slow to be implemented.

The bolt handle of the M1919A4 was replaced by what was originally called "Stud, bolt" and was used on the M1918M1 and M1919 Browning Aircraft Machine Guns which had a similar bolt retracting design.

The original drawing, A20545, for the stud dates from April 4, 1927 when the Class and Division drawing was converted to the new letter prefix system.


This rather grainy reproduction of A20545 Revision 5 shows the take down pin being added by revision 4 (2-19-43).


This Draftsman's Work Order gives some insight to how the Ordnance Department operated.

There are two changes in play here directed by two different "O.O." letters of authorization all rolled up into one revision. 

The earliest change is dated 1-13-43 and it is merely an administrative issue, removing two weapons, both obsolete aircraft machine guns, from the list of weapons that the part depicted in this particular drawing pertains to.

The second, dated 2-8-43 authorized a design change to the part to provide "a lock frame dissembling tool", the take down pin.

This change, Revision 4, resulted in a suffix change to the piece mark, adding -4 to the original A20545 piece mark even though the part was never actually imprinted with the piece mark at all.

Revision dates were specified by the authorizing letter and usually differed from the actual dates when the drawings were revised.

Ordnance must have thought the take down pin was an important improvement as they indicate that this change was mandatory and was to be implemented ASAP without interfering with production schedules. 

This would be another case where the Ordnance District supervising the contract would negotiate with the manufacturer for the timing of the change in part design.

Here's an actual picture of the A20545-4 Stud courtesy of Rollin Lofdahl.

Goldsmith in Volume 1 of the The Browning Machine Gun, which is a must have for the serious student of this weapon, indicates that about 40,000 M1919A5's were produced.

According to Goldsmith's figures in Volume 1 RIA manufactured about 14,300 A5's and likely converted the 3,000 A4's mentioned in OCM  Item 17705 the balance of the 40,000 could have been produced by Saginaw Steering Gear or Buffalo Arms.

Production of the A5 at RIA ended in April of 1943 and the M3 light tanks were declared obsolete in the fall of 1943. 

By the end of the M3 light tank production in October 1943 about 13,900 had been produced not all of which required the A5 for coaxial mounting.

If the 40,000 figure is accurate, and there is no reason to believe its not, the army ended up with quite a few A5's and A4 Fixed models and nothing to use them on. 

That's when the fun started. 

The demand for A4 Flexible and the new M1919A6 provided the impetus for the conversion of many A4 Fixed and A5 models to be converted into something more useful.

Since the basic mechanisms for the weapons were all the same, it was a simple matter to convert weapons into a more desirable form.

Converting A4 Fixed to A4 Flexible was as simple as changing out the back plate assembly, you didn't even have to remark the side plates as the markings were the same.

M1919A5 to A4 or A6 only required removing the retracting handle, guides, adding sights, switching out the back plate and providing a bolt handle in lieu of the bolt stud and adding any model specific parts required and remarking the side plate.

This picture is of a M1919A4/A5/A6 taken by the author at and through the courtesy of the RIA Museum. 

The bolt handle is missing and the stock clamp is positioned incorrectly but this picture shows the 4 holes formerly used to rivet on the retracting bar guides, the EB inspectors mark, RIA rebuild stamp which was not really required because the weapon was modified at the same facility that originally built it, indicate a rebuild that took place after Elmer Bjerke assumed his duties as Inspector of Small Arms in January of 1947.

One interesting thing is that this particular serial number 302743 should have been produced in 1941, however if it began life as an A4 as the side plate markings suggest, there should be a rivet hole in the right side plate for attachment of a bolt latch.

There are a couple of scenarios to explain the lack of the rivet hole. 

One would be that the plates were not serialized or used in numerical order and this plate did not get to the top of the pile until after May 1943 when the bolt latch was eliminated.

Another would be this plate was an A4 converted into an A5 before assembly to the casing being an A5 it would not need the rivet hole because A5's were not equipped with bolt latches.

It is possible that this particular weapon never left RIA and its entire service life was as a test bed for various designs. 

The RIA Museum's collection contains many "one-of-a-kind" odd ball weapons including a M1919 having bolt handle slots in both side plates, an early attempt at dual feed capability.

The idea of utilizing whatever was at hand to produce the weapons needed extended all the way to the April 1970 Depot Maintenance Work Requirements document pictured below.

  Paragraph 9 f  contains the directive to use various "assets" to produce needed weapons.

The M1919A5 story is, in my opinion, an interesting view of how the Ordnance Department grappled with the need to produce weapons under wartime conditions.

I hope you found reading this article as interesting as I have had researching and writing it. 

Its time to close this chapter in the history of the M1919 and thank all those who made this possible.


The Rock Island Arsenal Museum Staff and in particular Jodie Creen Wesemann Museum  Specialist-Registrar for their assistance.

Without these dedicated people much of the history of the M1919's would have disappeared into the mists of time.  All of the documents reproduced in this article not otherwise credited were provided through the courtesy of the Rock Island Arsenal Museum.

Rollin Lofdahl who provided photos and real world knowledge of M1919A5 parts.

Tom Chial who provided cuts from TM's and FM's that help to give perspective to the subject.