I don't have either rifle or have I ever shot one. But I do own a RR LAR-8 and have put over 400 round through it with out one hicup. It is accurate 1moa with the right load and has shot everything I've put through it 2moa or better. That being said they have no compatibility with any after market parts besides the ones sold by RockRiver.
For that reason it is for sale. PM me if you want it. I will give you a good price.)
