I am building an AR15. It is being used with The HI-PRO DPMS side charging upper. I have a 28 in. Freefloat Walterloather barrel for the upper. SO far things are always changing

It might be done for a 300WSM cart. Right now wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww

Where do I find the bolt and carrier to start this project. It is going to be free-floated and used for other reasons in another Calaber.

I also need some info on some Accuracy International parts, If not a whole setuP

This is very important I need info on a Blasur also and availability

You need to be more specific on the AI and Blaser thing we have no idea what you want to know.  As far as AI parts the ontl parts you can get is the Remington 700 stock system in folding or non folding.  Other than that you will have to get an entire rifle.