I have started building a few .375 and .416 Ruger rifles for a couple of friends and myself. All of them are going to be on Model 70 classic actions that were originally .300 Win mag or .338 win mag. I got the first .416 threaded and chambered and then test fired. The belted magnum magazine box and or the follower are not working well for retaining and feeding the Ruger cartridges. Wondering if anyone has experimented with different magazine components and had success.