critical hit / wild blow

i was doing some damage ranging on the target dummies with an axe using wild blow. wild blow says that the attack always results in a critical hit, and does not say it adds damage. when i used wild blow it always came out to 61 damage, which lead me to belive that is what the critical strike damage is.
however, i swung my axe at the dummies, using no attack skills or axe mods, and the highest i ever got was 55 damage. in fact about 1 out of 4 of my hits were 55, which lead me to belive that 55 was the actual critical strike damage. i used wild blow and swung my axe at the 60AL targets without changing axes or anything.
i know it doesnt really matter, but could this mean wild blow has hidden +dmg? and has anyone noticed this before?
i used a +5 energy axe (no 15% mod) with no haft, 16 axe mastery, and 10 strength

in case you are curious as to why im number ranging in a game, i have alot of free time and i challenge other's data :P

Was your strength 0 as well?

sorry, had 10 strength.