Thanks, I read a bunch of posts but I know for myself it is always easier to understand when you can see it happen

I read a few posts but left a few questions unanswered so I worked through it and asked a few more questions. Figured I'm not the only one that needs to see it for it to make sense. Glad it helped.

Yes that is correct M4 x 0.5 - be very careful when ordering, most common in North America is m4 x 0.7 and lots of places I found only list M4 and not the threads per inch. I had to order from Europe and waited several weeks for it to arrive, remember to order the matching nut too :)

Let me check and get back to you. I was playing around with some different reloads at the same time and found a set up that seemed to minimize the dented brass, although not completely eliminated. I will post that and the screw setting.

Okay, the last setting I currently have dialed in is to bottom the screw out (lightly) and then back it out 1/2 to 5/8 of a turn. So that is probably close to 3/4 of the way in. This will also depend on what you are using for ammo and loads. I would recommend dialing the screw in until the action just barely cycles and then back it out a bit. Enough for reliable cycling but the least force possible. From reading online a lot of people were recommending faster burning loads so I experimented with a couple and found that IMR3031 31.5g with a Lapua 144gr boat tail and IMR4895 33gr with a Lapua 144 gr boat tail worked well with this set up and minimal brass damaged. I have run a bunch of PPU preloaded with 139gr as well but I believe those have a slower powder more for bolt action. Please note, I am not an expert at reloading and have only just started experimenting with loads, not pushing any listed limits. If you try these loads please only do so if you have experience reloading and at your own risk.

I would keep at it with the penetrating oil, several times a day for up to a week. Also, each time you reapply oil place a flat blade screwdriver in the screw and give it a couple taps with a hammer. Helps to shock the threads that may be frozen or rusted. If after a week of that it doesn't loosen it up you could also try an impact screw driver....but you run the risk of destroying the head of the screw or scratching your gun if it slips while you are hammering it. If there is any way to get penetrating into the other end of the gas tube and let it run down to the other end of the screw that should help as well. Not sure how to remove the gas tube but Ill try to take a look this week.

After reading a number of forms dedicated to Ljungmans I don't recommend trying to remove the gas tube. Sounds like a combo of heat fitting and pinning that holds it in place. if you need to clean it i would recommend a good quality gun cleaning solvent don't the gas tube and then back flush with pressurized air. Don't put air into the gas tube as it may force dirt into the elbow by the screw, instead blow air up the barrel and block off the chamber thereby forcing the air out the gas tube in the same direction as if it was fired. Hope this helps

Yes, mine does as well. Tuning the port helps and most are fine or small dent in the neck. Minor enough that resizing while reloading will fix it. As well, make sure the rubber bumper is in place behind the ejection port.

Thanks,! Ya I love shooting the AG42, just cant ever find the brass after :) working on some reloads but now that I put the adjustment screw in I basically need to start over

Made a peep sight too, pretty easy if you got the patience. Hitting a 10" gong at 300 yds kzfaq.info/get/bejne/oauVmpd7uq-yZX0.html