If I remember right they were offered by Winchester using Nosler's coated ballistic tip. They were good rounds that were offered back during the Moly coating craze. I never shot any in .45-70 but they had a 55 grain loading in .243 that was absolute death on varmints at 4,000fps and very accurate in my old model 70 varminter.
Yep, Nosler CTs. I have about 400 left in .243 55 grain I use in both my 243 AR 10s and some in various sizes in .224. I also have a box, and then some, of 180 grain Partition Gold 180 grain .308s for my 300 RUM. Good stuff…wish they still offered them. I have tested the non coated 40 grain (plain old Nosler ballistic tips) vs the coated accuracy in my Remington LTR. Both with shoot .3”s at 200 yards for me with 27.0 grains of benchmark.