You can get a Wyatt extended magazine from Brownells for the Rem short action so the 284 will work. I have one up the gunsmith now being finished. My first wildcat was a 7x57AI years ago, I got almost 7mag velocity with bullets up to 160gr using 10gr of powder less. Another choice would be the rem short mag case in 7mm or the wsm case give you plenty of velocity with either and not have to fireform cases, sure want to use the Wyatt magazine box and have them throated out long to get alittle more case capacity with those cases. Only reason I'm talking about different cases is I got a 7mm Kreiger barrel coming and I'm looking for a caliber. I think the 7-08 is a good case left alone, I use to shoot a shorten 7-08 think that improved that case alittle got better velocity than the standard 7-08. I was shooting a short 308 back then so making cases for either wasn't a big deal.