Model 12 repeater to 6mm brx detachable magazine conversion

I am interested in taking a savage model 12 in a short action and changing the barrel out for a 6mm brx from Shilen in a 1:8 twist. I am hoping to use the magazine in the following link from a web site called cheaper than dirt to just have a plug and play feeding magazine. http://www.cheaperthandirt.com/product/52981

I do not have the model 12 purchased yet but was looking at like I mentioned a short action model 12 in .243, .308, or even a .223 though this I understand would require a change in the bolt face.

Why you ask?
I like what I have seen for ballistics and low powder usage on the 6mm brx, I like the long barrel life, good case life. I want to use the gun as a low recoil coyote hunting gun for those days when coyotes just don't want to come any closer than six or seven hundred yards and hang up. I will mount a bushnell tactical ers g2 retical 4-21 x50 mm scope in a 34 mil tube. I may even go so far as adding a suppressor in the future.

I know there will be a few individuals that think I should just get the .243 and leave it as it is. I would say to those folks I already have a .243 and don't really want to go that route. I feel the current ballistics I see on several forums support the 6mm brx as being capable of more than a factory .243 with less power in each cartridge. Less powder I feel will equal less recoil which equals I hope better 2nd shots on doubles and triple coyote situations (just my opinion I am not trying to stomp on yours)

I admit I am far from a savage expert and so was hoping you could give some in site in to if this after market magazine will work with any model 12 or only a specific gun already set up by savage as a 6mm br repeater.

The savage custom shop will make this rifle in either a predator or 12btc model but it's about $300 more than if I just get my own components and assemble. And I would be limited to 6mm br instead of the improved shoulder brx version.

That magazine will work for that conversion, but I don't know why you would want to go to all that trouble for a coyote rifle. A fast twist 22-250 or AI with heavy bullets will shoot faster and flatter, giving you more margin for shooter error, not the mention easier and less expensive to make brass. I wouldn't worry about barrel life, if you shoot that barrel out just at coyotes, you should have have enough hides accumulated to buy a few more.;)