I gave my metagross a muscle wing, But it said it had "no effect?" does this mean its attack stat is maxed Ev trained?

Question

I was Ev training my metagross and I thought a few muscle wings will make gaining a few Evs a bit easier. I collected 3 went to give them to my metagross (Whom I've been Ev training) and it said it had no effect? is my metagross attack stat maxed out?

Answer 1

Well yes your attack is maxed for you can use the wings 255 times here is the proof
, but if you have already maxed your evs then no more ev training for your Pokemon .The highest amount of evs you can give your Pokemon is 510 evs. You can look up here
to get more info.

Answer 2

Yes,
Since Wings are not subject to the 100 EV cap rule, unlike Vitamins you can keep on using them until you have reached the total EV peak of 510 or the maximum EVs for a single stat, 255. So yes, you have reached the maximum amount of attack EVs (or total EVs, but since you're training attack, probably just one area :P)