Hello, I’m going to buy my first sporting rifle. My options are a Bushmaster XM15-E2S (post ban) or a Ruger AR-556. Both 1/8 twist. Both 556. Both used but in nice condition. The prices are about the same. I‘m most interested on peoples opinion of which rifle has the best “chassis”and barrel. Both rifles I would upgrading stock, forearm and possibly trigger. I’m and avid shooter of pistols and rifles. But know very little of the AR world. Thank!