By specifying that it has to be remington factory ammo you limit yourself quite a bit. The 180 gr core-lokt should serve your purposes okay. Any factory 180 gr load should work. My preference would probably go towards the federal premium stuff with a nosler partition. I don't use factory stuff any more, it's all handloads, but if I did then remington ammo would be my last choice. It's the only brand I've ever had misfire. One particular box of 30-30 ammo failed to shoot half the rounds out of the box. For that reason I don't use remington primers in my handloads either.