Heckler an Koch gunsmiths

IIRC you will need a hydraulic press. Back when I was an HK addict I had an original German lug barrel put on my MP5 and Fleming had to do it because they were the only ones with a hydraulic press set up for HK work. FWIW there is a lot of flex in the sheet metal receiver and I am not sure the expense of putting a high grade barrel on it will give enough benefit for the cost. Just my
My HK 91 and 93 rifles were super dependable but weren't the most accurate semis in the safe, they had acceptable military grade accuracy but I wouldn't want to shoot say, the combat precision match on the "D" target with one. They are definitely fun and cool rifles...

Definitely a reliable, rugged rifle, the G3 (HK91). When you consider that West German draftees were only in the Bundeswehr for less than 2 years(1950s - 1990s), they could put a G3 in their hands and have them hit "minute of man" as you say in a relatively short period of training time, this in a society where few had toy guns, let alone exposure to real firearms. By the end of the draft(last year) draftees only served about 1 yr, I don't know how they expected to turn them into real Soldaten in that brief time - but I digress.

Beladran, if you know someone going to Germany, they could purchase a barrel and bring it back...Ulrich are barrels restricted items now? I know at one time they weren't, I brought back parts in the past...but that was before 2001.