I have a 22" barrel though I shoot very little factory ammo. Been a few years now. I may have had similar results. Reloading with Power pro 2000 was one path to accuracy for me. Other bullets do very well also. I am not a big fan of the 6mm ARC for non reloaders as of yet due to the lack of options that can frequently result in similar results as yours.
If your barrel is threaded I can only hope a muzzle device may improve your delima. https://www.harrellsprecision.com/produc...0895838464
If your barrel is threaded I can only hope a muzzle device may improve your delima. https://www.harrellsprecision.com/produc...0895838464