Well I never had a G3 more than about five hours.......then the German Army took it back.
At the time my US Army issue rifle was an M-16A1 used with M193 ball and LSA for lube. I liked the G3 a lot more than that, then.
The German Troopers indicated that though they had fewer failures with their rifles that as often as not a failure meant popping off the butt stock and flailing about to clear. Even if the "jam" was a simple failure to go full into battery. They thought our forward assist was a GOOD thing. Later G3 rifles had a "finger print" on the bolt carrier to allow the trooper to over come that last little bit of forward travel when a stoppage occurred. I was told and shown however that the stoppage was most likely to happen on a hot gun and that the finger print might well be yours in reverse image after use.....that is it functioned as a mini branding iron.
'Rad had a big ugly BFA (Blank Firing Attachment) that replaced the flash suppressor and had two settings for different sized holes and two threaded areas on the BFA for attachment......the same one being used for the G3 and Uzi. They used in the G3 a blank that had a brass base area only about half an inch long onto which a plastic "cartridge" was attached. When fired a small X on the "bullet" (not a separate part) gave way for the gasses. We salvaged the brass bases to make "Hollywood" BFAs for our M-16A1 rifles. We would cut away the plastic and if a hack saw blade were available (individuals in my squad/platoon each carried a tool for group use, like Mad Max I had a crescent wrench which came in handy for removing an replacing the M-16A1 flash suppressor) the portion of the base that held the plastic portion was cut away from the actual base area of the brass leaving a less than 1/4 inch brass disc that with the primer removed when slipped under a removed flash suppressor and the flash suppressor and the FS cranked back on gave an invisible BFA.....like in a Hollywood movie. You could really get in trouble for them.....if anyone cared and no way would I do that with my personally owned AR15 and neither should you.
Most of the German troops ignored the 100 meter range setting on the sights in day light. That setting was a large cutout with a simple notch that was too close to the eye for such a thing. It did work well for centering the whole front sight ring in for evening and early morning use at close range. We used the "2" setting for 100 and 200 meter shooting for the qualification and shooting knot award
The German troops used their slings for chow. That is the only time I saw them in use, in the chow line and keeping both hands free for eating. On marches they invariably shoved the rifles through their front pack straps across their chests. The smaller guys actually made loops of the portion of the strap used to tighten the pack and stuck the rifle high across their chests in the loops.
Panzer Grenadiers mounted in the old Marder AFVs were some times issued a fairly straight 30 round magazine I have never seen anywhere else. I never got t use one. They were intended for use in the dismount phase and final assault from the Marder.
The G3 was much less controllable to me on full auto than an M-14, your mileage may very. During summer when on a range and not wearing body armor, a field Jacket, or suspenders the G3 sometimes left an interesting bruise on the shoulder. You could see the individual horizontal gripping surfaces from the butt plate in the bruise and the out line of the butt plate.
Many of the German troops referred to our M-16A1 rifles as "Frau und Kind Gewar" that is suitable only for arming (or shooting) women and children. Many of the older German NCOs in the early 70's insisted on referring to the M-16A1 as a Machine Pistol. The ancient paratrooper First Sargent (Gosh he was younger then than I am now) that noted the similarity of the M60 GPMG to the FG42 he carried in 1944 was among the ones calling the M-16A1 a Machine Pistol at every opportunity. All the French troops I helped cross train on the G3 and M-16A1 liked the G3 better than the MAS 49/56 with grenade launcher but all liked the M-16a1 better......because of its lack of weight and recoil. Draftees. Got to love 'em.
-kBob