I use the silvertips and they are DEVASTATING on deer. Every gun likes different ammo and your friend's rifles prolly don't like silvertips.
First, when it comes to "knowing things", friends can hurt you more than help you. If you do your own research, you will be surprised how much other information you learn along the waythat you didn'texpect to learn.
Secondly, accuracy is determined by so much more than a name on a bullet. It involves velocity, rotational rates, trajectory paths, weight ratios and distribution, cartridge design, etc. Bullet making/marketing is a very competitive field and engineers put a lot of effort into designing good quality bullets and cartridges, so its kind of silly to listen to a friend make such a broad statement about a bullet type when im sure the only experience he has with that bullet type is probably limited toone rifle. Im not saying that the bullet didnt perform poorly in his rifle, but you have to consider the probable fact that he has only used that type of round in only one of his rifles before deciding to tell people it wasnt a good round. Afterall, the silvertips are an extremely popular round and its for a reason, it's because they work.
If your rifle shoots them that well, then like mentioned above, you lucked out and saved a lot of money that most people spend looking for hte type of round that suits their rifle best. You should be happy and thrilled with your find so go out and shoot. Ask your buddy to come out and shoot with you, and after your grouping leaves his in the smoke, let him know what "crappy bullet" you are using.