For all the effort you will put into this, I think you would be well served to add a new stock to the build. To start you will need to get a PTG bolt with a M16 style extractor.Dan40x can weld on the bolt handle. Next blueprint the action and open up the rails to let that case through. I would recomend the HS detachable mag system to give you center feed and eliminate feeding problems. This round will work well in a 26" barrel, which should be of at least a Sendero contour with a 4 port DE brake. Put on a good 20MOA rail and you will have a good start. I have used the Manners T3 and can highly recommend it. Good luck and I wish you well, My friend's 28" Rock is getting 2800 with 300SMK's and Magnum powder.