OK, I'm pretty sure even HKPro doesn't have a picture of one of these.
As most people know the HK G3 was HKs first rifle and was adopted by the German military in 1959. And most understand the HK91 is a semi auto civilian version of that rifle.
But long before there was an HK91, and even before the HK41 the very FIRST HK semi auto civilian import rifle was the HKG3 semi.
This one is dated 1962 and not very many were imported before ATF required many changes to prevent it from being readily converted to a select fire rifle and those changes would result in the Hk41 semi auto rifle. This one is a second series as the first series receiver was not changed in any way (except markings) and was a G3 push pin receiver with a semi only trigger group.
This one is a Golden State Arms import. Recent collectors will fail to grasp the notion that at one time a handful of decades ago Golden State in California was the single largest importer of military and surplus rifles in the entire country. The second largest was ironically in NY.
One first glance it seems like a standard semi trigger pack, except for the obvious relocation of the push pin.
But when you pull the trigger mechanism things are very, very different.
Once removed the hammer cannot be locked down in the cocked position like current HK semi auto packs can. HK removed several key parts to prevent it from being readily converted to a select fire.
So what lets it function when installed into the frame?
Well that would be this little ingenious setup here. Note the spring inside the trigger frame.
That little spring engages the internals when installed and permits the hammer to be reset when fired. The bottom of the spring is also viewable in front of the trigger.
What is funny is this setup actually permits the occasional double burst (especially when the spring is nearly 50 years old) and probably a big reason for design changes that led to the HK41.
The bolt group is about identical to a current HK91 bolt group with very minor differences.
For some reason HK felt compelled to cut a channel in the bolt carrier to make it a dedicated semi auto carrier.
Now here is where it gets interesting. HK started with a military G3 receiver and then welded this shelf in place which provided a offset push pin location.
Obviously it would be a simple matter of removing the welded piece and PRESTO ready for install (though illegal if not registered) machine gun. Keep in mind this was 1962 and you could still register machine guns.
The early G3s, including the semi import still bore a striking similarity to the Spanish CETME (which should be no surprise as the CETME was built by the Mauser engineers who would later form H&K while they were in Spain as a result of arms production being prohibited in Germany at the time).
Here you can see the same style cocking handle found on CETME rifles.
And identical to the G3 machine gun the HK semi rifle had the early non tapering cocking tubes, bayonet mount (it's the front of the cocking tube) and intact grenade launching rings (something you won't find on any HK91).
There is also another ring that keeps the front of the old slimline handguards from sliding back and forth.
And like the G3 assault rifle, the semi also maintains the paddle magazine release.
One of the changes made at HK which resulted in a designation change from the G2 (which was the CETME) to the G3 was the diopter rear sight as opposed to the CETME flip rear sight.
And of course there is that beautiful G3 wooden furniture which closely resembles the wood furniture on the Spanish CETME rifle.