The Top cover is the part of the gun that mounts onto the top of the receiver and covers the action of the firearm.
What does it do ?
It holds the belt-feeding mechanism and synchronizes the cartridges being fed with the action of the bolt for proper timing.
Where does it go ?
On top of the rear of the receiver connected at the Camming piece and latching back by THE BUFFER.
How does it attach ?
It is attached to the camming piece by a pin with a flat spot .
The top cover AND feed tray need to be held 90 degrees vertical to the receiver when the pin is installed. Then the three pieces are rotated down and the pin locks into grooves on the camming piece preventing the pin from coming loose.
What are the different types ?
Well , the obvious two are the original
" MG42 type " that is designed for 8MM ammunition, and the latter
" MG3 type " designed to work with 7.62 X 51MM NATO ammunition (AKA .308 Win ).
There are also Wartime and Postwar variations that will , I believe, fit any firearm in the series but have different collectible values. The MG42 series has been or is currently being made in at least Germany ,Yugoslavia , and Pakistan. All top covers and feedtrays should be usable on any receiver.
The different parts have greatly different values to collectors so beware before you alter or destroy a valuable collectable.
shown in picture , 308 top cover on top , 8MM top cover on bottom
How many pieces should my top cover have ?
- 7 total
1) the main body of the top cover
2) the feed pawls
3) the connecting lever
4) the operating lever
5) top cover latch with spring and bolt
6) the pressure plate with spring and pin
7) Top cover hinge pin
Shown in picture (below the tape measure left to right clockwise,)
1) the feed pawls
2) the connecting lever
3) the operating lever
4) top cover latch with spring and bolt
5) the pressure plate with spring and pin
6) Top cover hinge pin
Click here for the complete parts breakdown for the MG42.
7.62 X 51 topcover parts above tape measure , 8MM parts shown below tape measure for comparison.
How do i assemble it ?
see picture .
Are all the internal parts compatible ?
YES and NO ,
The two top covers have 2 different sized
1) feed pawls, Mg3 should work in mg42 but not the other way.
2) connecting lever, mg42 has roughly equal length arms, Mg3 has one arm longer that works the feed pawl.
3) The operating lever for the MG42 is shorter because of the longer 8MM round , approximately 8 3/8" long.
The MG3 operating lever is longer at 8 7/8".
The MG3 operating lever will not work on a MG42/MG1 8MM top cover ,but
A MG42 operating lever may work on a MG3 top cover but it will have a 1/2" gap behind the feed tray which just seems like a bad idea.
Are they compatible with just any feed tray?
YES and NO ,
An original 8MM top cover (MG42) will work with
1) an original mg42 8MM feed tray
2) a MG42 8MM feed tray converted to an MG1 .308 feed tray.
NOT a MG2 or MG3 feed tray.
A dedicated .308 top cover whether designated MG2 or MG3 will work with either
1) A MG2 feed tray using DM1 belts only.
2) A MG3 feed tray using DM13 links or DM1 belts (if you don't mind the extra wear on your belts).
but NOT a MG1 or 8MM feed tray.
What do the different Feed trays look like ?
Here is a picture showing the four variants.
from left to right,
- 1) MG 42 - 8MM with drum mounting tabs
2) MG 1 - An 8MM tray converted by adding a feed block and removing the drum mount tabs. ( shown with an 8MM and .308 round on it)
3) MG 2 - Always a .308 tray patterned after the larger 8MM tray.
4) MG 3 - This one is very distinctive as its been redesigned to work with DM13 links (M60 links) . It has an extra set of feed pawls and a large bracket for mounting both drums and boxes.
A extra close-up picture of the MG 3 feed tray.
MG 42 = pure 8MM
MG 1 = hybrid .308/8MM
MG 2 = pure .308 patterned after 8MM
MG 3 = pure .308
What modifications are required to convert the Top cover to work in the semi-auto SA42 ?
some Top covers , MG3 type will require the spring sometimes found on the feed lever to be removed to be compatible with the SA closed bolt system.
What modifications are required to convert the Feed tray to work in the semi-auto SA42 ?