The bullets look like they are possibly jacketed. If the outer shell of the bullet is copper or a copper alloy and the inner is lead, then no. Lightly scratching the outer surface with a knife blade will tell the story. As said above a little precise information on size and weight will go a long way in the ID. They resemble .45 ACP to me. Though the outer is a white chalky look similar to oxidized lead I have dug jacketed bullets encrusted with earth that appear similar. Anxious to hear after you give a little more info. Either way congrats and HH
PS .... A measured outer diameter of approximately .452 and a weight of 230 grains (.525 oz) will confirm .45 ACP