I have a prohunter with the factory 7-08 barrel and there is a gap on a Warne one piece base, but there will we on any base on a tapered barrel. I have had good luck with the Warne stuff. I would definately go with steel bases. Don't use aluminum and I think you will be fine. I have a Leupold QR base on my MZ barrel and there is a gap, but no problems. Good luck and enjoy!