I received a catalogue from Federal Arms Corp.
They have a rifle kit and receiver you can buy
to make a G3/HK91 .308. Has anyone put one of
these together? If so,how did work out?

I bought a G3 with a Federal receiver that was already assembled. I asked my gunsmith about the kits & he said unless one was really knowledgeable about firearms, they stood a real good chance of screwing the thing up.

Apparently the big thing is head spacing the barrel. Too much or too little & it causes all sorts of problems.

So I bought one ready-to-go & loaded up & have been having fun with it ever since.

My .o2

I have built a HK91. It is something that does take some welding and machining knowledge. The headspacing is a very critical thing in a HK weapon. As most weapons in time the head spacing will get larger in a HK it will get tighter. So I undetrstand,correct me if I am wrong. The barrel is pressed in the reciever trunion. Then the headspace is checked,when correct headspace is set it is drilled and pinned in place. Very tedious process. If you don't have access to the right equipment I would not even consider taking on this project. Also the new FAC barrels are junk!!!! I found this out the hard way. Put gun together,had it parked, Go to shoot it, BANG!!, shell does not extract! It has swelled in the fluted chamber and will not come out. Had to remove barrel, which is a bitch! Then get a real HK barrel, press it in and test fire,BANG, BANG works awesome. But if you do not have the time,tools or knowledge just go buy on assembled. Hope I helped

Thanks for the input. I'm going to pass on this
project. I don't have the tools or the knowledge.