Looks like a BCA bolt action upper would be the ticket for you.
Jay
Precision made Bolt Action Style Uppers | Bear Creek Arsenal
Bear Creek Arsenal's Bolt Action Style Uppers, blending bolt-action accuracy with AR adaptability. Perfect choice for precision shooters and hunters at low costs!www.bearcreekarsenal.com
That’s the one I was looking at for the ARC as I had read here the Solo 300 was having issues with the ARC cartridges.