here's the thing...first off...no one is ripping off anyone slimbs..period...after the admantium bonding process is completed it is stuck the way it is sculpted for eternity..the only other changes it goes through are molecular bonding...not only was there a blurb about this in either weapon x, or during a weapon x story arch, but professor x himself has claimed wolverine's skeleton to be bonded at a molecular level...and it has been proven on a vast amount of occasions. that's said..no limbs will be ripped of okay...
now as for wolverine being able to penetrate colossus...apparently colossus 616 is quite afraid of wolverine's claws...wolverine once took a casual swipe at him and he toppled over after he dodged out of their way in fear of being tagged "wolverine, your claws!"
so if peter thinks wolverine can hurt him, and wolverine can cut through almost anything..it's not so hard to believe that he can cut through peter is it? and as for sabretooth I think admantium claws backed by a class 5 to 10 warrior are wayyy more than enough to get some damage done on the the big C, but that's just my opinion...
that's why I was asking about whether or not wolverine's ever tried to hit colussus with his claws...cause the only time I've ever seen him try, big C was hella scared of em.