I have muzzy 125 grain 3 blades, and i have 24.5 inch arrows, and i was wondering if 125 is too much for them, by the way my bow is 50 lbs. and they are easton st epics 500's.

No, you should be fine. Your arrow probably weighs around 340 grains which is fine and that 125 gr head will give you a good Front of Center. You probably don't want to go below 250 grains for your draw weight, so that gives you a lot of room to work. You could easily go down to 100 gr or even 85gr for a little more speed but why buy new broadheads.

i dont really need nor want speed, when speed comes you have more noise, me i believe shotplacement counts, not speed.

Definitely stick with the 125's then. A 340 gr arrow is still not a heavy arrow and you'll get good performance from them.

Actually , for the specs you gave the 500's are overspined anyway so dont go any lower on the BH weight.

how can they be over spined???? then what spine size should i use???? that is what the pro shop set me up at, and he was looking at the graph and so was i and it did say 500.

It is pretty tough to find a hunting arrow with a spine softer than 500, so you are going to have to make the best of the slightly too stiff arrow - which is a lot better than than trying to make the best of a slightly too weak arrow. Next time, if you get the charts out first, you might consider leaving your shafts longer than they need to be to get the spine closer to ideal.

Don't get too technical about this. Shoot the darn things and be happy. If they fly well with your chosen broadhead then so be it.

I know all this stuff about spine and what is supposed to work, but I can and often shoot my Gold Tip Pro 22 series arrows down as low as 48# at 27", and these arrows are a .300 spine. Who cares. I can get them to work. Not perfect, but decent enough for Vegas rounds indoors and 3D.

For hunting I use a GT UL-500 spine and 75gr heads out of 27" and 53#. Now, these shoot perfectly.

Have fun.

Without running the numbers it's hard to tell I seems to be borderline between 500's and 400 just because of the shorter arrow.
I shoot 56 pounds 27 1/2 arrow 400 spine for 3D but 340 spine for huntingbecause I use a 220 grain Muzzy Phantom w/ the bleeder vanes.

You should be fine. I'd definitely stay with the 125 grain broadheads.

Dan