Best thing to do with the AG42B is to mod the gas takeoff so that it uses less gas, then handload with a 140 bullet an a fast powder: exactly as posted above in several places.
Using a 160 bullet will give too much dwell on the gas: too drawn-out a push.
Using a slow powder will increase port pressure, which is the LAST thing this critter needs. The 140 or 139 is this rifle's bullet; it's what they were designed for. Ditto for fast powders. MAYBE the designer knew something about it.
Oiling your brass will ease extraction by making the case float in the chamber during firing. It will also put incredibly unsafe pressures on the bolt.
If you want reliable operation with zero problems, just mod the gas block for an adjusting set-screw: cheap, reliable, gets rid of all the problems.
Watch out for that Norwegian ammo the boys bring back from the ice: bullets are too heavy, too slow for this rifle. She'll wing her shucks about 20 fathom and they'll hurt when they hits. Mod the gas block and you can run even this stuff safely. It's really accurate, too!
Heavy, yes. Loud, yes. Accurate? Also a very big yes.
Complicated? Thing strips into frame, mag, bolt, carrier, recoil mech and safety block: 6 pieces. Compare that to a Kar 43 or a Gew41W or something.
I have one and I'm not selling it.
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