I was wondering what would be a better choice for mule deer hunting in California a 3 blade or 4 blade broadhead, and please specify what brand it is.

I use a 100 grain 3-blade muzzy. Try a 3 and 4 and see if one shoots better. There is no difference for me, I just prefer 3 blade.

"Semper Fi"

Whichever one shoots better out of your setup..Technically though, compared to a 3 blade and all else being equal, the 4 blade has more surface cutting area.

~Will Hunt For Food~

As far as being better choice, I can't really say. I think that is more of a preference thing. Both should work fine for you. Personally, I would take the four bladed head. Muzzy is a brand that I would always recommend to anyone who asks. I don't believe that you could go wrong for mule deer with any of muzzy's models over 100 grain.

I prefer 3 blade although I have taken deer with 4 blades. Cyclone is correct that the 4 blade will provide more cutting surface. If you have ample KE either will work well as far as penetration goes especially on medium size animals like deer. If your worried about penetration look at the three blade. I love Wasp SST checkout their website.