Browning Backplates

This site is intended to provide information for identifying the many backplates which have, over the years, been issued on various Colt & Browning cal. .30 machine guns. If you have an image or information you would be willing to share, please E-MAIL me. Thanks to Mark Genovese for his contribution of images and his patience is answering my endless questions. Jon (a.k.a. Nosegunner)

Click on images to enlarge

In addition to forming the rear of the weapon's receiver, the backplate also contained a buffer which was designed to arrest the rearward movement of the recoiling bolt. In most cases the buffer was horizontal, in line with the travel of the bolt. In some cases, however, the buffer was vertical. This required components which changed the direction of force 90 degrees.

Typical buffer configuration with a horizontal row of buffer disks.
(Flexible backplate)

One version of a 1919 fixed backplate had a short horizontal recoil buffer.

An early fixed 1919 design had a backplate with a vertical buffer. Wedge shaped buffer plates redirect horizontal forces upward.

Sources: Drawings - Alan Little, photo at far right - Rick Shab

Left:
The early FN30 had a vertical buffered backplate.

Right:
Later versions utilized a short horizontal buffer.

Photo plate from the 1955 FM23-55 manual showing the four basic pistol grip style backplates used on the ground cal. .30 Browning MGs. The large slot in the bottom of the 1919 handle grasps the lower elevating screw of the M2 tripod's T&E when the gun is being transported in the field.

The most common 1919 backplate,
one piece, cast.

When the 1919 was put into production, 1917 backplates were fitted with a one piece aluminum grip in place of the earlier plastic slabs. The FM23-55 manual refers to this as the 1919A6 backplate, though I have seen it most often on the A4.

The same backplate with the aluminum grip removed. Note backplate screw retaining pin & spring are in the handle as in the cast 1919 grip. The earlier backplates had the spring assembly in the screw. The yellow dot (red arrow) shows location of alignment pin on the 1917. This pin was left out on the backplates intended for use with the aluminum grip.

WW2 era photo of a 1919A4 with the
aluminum handled backplate.

Aluminum gripped 1919A4 on M2 tripod.

Parts blowup from the
TM9-1005-212-25 manual.

Standard buffer assembly for the 1917 & 1919 model MGs

What's the deal with the spring clip in the bottom of the handle?

It may have been intended to hold the T&E when the gun is being transported in the field. The problem is, you have to unscrew the T&E all the way, and in the case of mine, lift the elevating screw stop (red arrow, at right) and unscrew the saddle (elevation screw sleeve) another 2 or 3 turns. This may be why I have never seen a WW2 photo of this feature in use. I have also heard that it was used to secure the rear of the gun to a mount or cradle, which seems far more likely.

Spring clip.

The M37 was a modification of the 1919 for use in tanks.
It featured right/left feed capability, link chute, bolt retracting bar, and a safety.

M37 backplate with safety.

M37

Parts blowup from the
TM9-1005-212-25 manual.

M37 backplate.

The two photos above show details of the safety and the latch mechanisms. The driving spring on the M37 is captive, and is mounted at the rear of the right side plate, hence no driving spring rod hole as on the 1919 and 1917.
Source: Thanks to MACHINEHEAD2 for sending the photos.

------------------------Argentine 1919 backplate------------------------

The Argentine contract 1919A4s have the signature Argentine thumb safety (see 1928 below). It also has the large serial number stamped above the buffer tube.

Thanks to Orion Arms for the pics.

------------------------The 1917 two piece backplate------------------------

1917 backplate with early
style wrap around wood grips.

1917 backplate with beveled
shoulder style wood grips.

The 1917 backplate with later plastic
beveled shoulder style plastic grips.

1917A1 on 1917A1 mount.

1917 backplate
on a 1919A4.

Early style 1917 on 1917 mount.
Note fitted wooden grips.

1917 two piece backplate.

WW2 1917 on 1917A1 mount.

Last style one piece cast 1917 backplate.

---------------The Colt commercial model 1928---------------

The 1928 backplate with grips removed. On these early backplates the backplate screw retaining pin & spring are in the screw.

Colt M37 1928 backplate with fitted wooden grips.

Rear view showing thumb safety.

Rear view of a Colt commercial 1928 on an M35 tripod. Note unique thumb safety.

The 1928 buffer system employed a split brass buffer ring into which a cone shaped steel buffer plug was forced at full recoil causing the brass to expand against the buffer tube.

Note that the backplate retaining pin & spring are in the backplate screw, and not the handle.