Ok I am new to the large frame gas guns however I asked opinions a couple weeks back between Wilson combat and Seekins. I was set on the Seekins and everyone confirmed it was the right move. I found one online posted as a 6.5CM the one I wanted. I bought it had it shipped to my FFL and picked it up only to realize the shop made a mistake and posted it wrong and filed all the paperwork wrong. It’s 6 Creed not 6.5CM. The shop is working with me to fix the mistake. There sales rep who has the relationship with Seekins says Seekins would like to swap barrels in house for QC reasons. I think the shop is going to give me other options as well. I told them I was good with a Proof barrel as well. My question is what other barrels should I consider to not jeopardize less than Seekins quality. And if a barrel is sent to me should I have it installed by a gun smith for proper headspace or is this not needed ?Don’t beat me up I am mainly a Bolt gun gun so the AR platform is not my strong point.