Newbie needs ammo year and id

I found this forum and I could use some expertise as I know little about bullets. I Metal Detect old trails in New Mexico and found this shell. It’s marked REM UMC 30-30. Through this web sight I learned this shell was made from 1912 to1956. Thought it odd the tip is powdery, ahead of the lead. Been underground awhile. Would like to know age and any other info will be appreciated… and Thanks.

This is a .30 Winchester center fire, popularly called the .30-30, manufactured by Remington-UMC. It has been in continuous production since 1895, primarily for the Winchester 1894 rifle and carbine. At one time Remington did manufacture a cartridge very similar to this one except it was rimless in design and early production specimens of this special Remington cartridge were identified as .30-30 Remington.

This Remington round was intended to be used in the Remington Model 8 semi-auto sporting rifle and that firm’s pump action sporter. The name caused a bunch of confusion, so Remington changed its designation to .30 Remington. There were also .25 and .32 caliber rimless cartridges of Remington design that went through the same process of name clarification.

The powdery looking tip of the bullet is lead, oxidized; the less corroded part of the bullet behind it is of a copper alloy. Jack