Magus Perfect Strike ability and Lead Blades spell

[Jeff Clem]

Can lead blades spell be used with the Magus Perfect Strike ability?
If the does work, could you apply this if you have more than one attack per round?

Perfect Strike (Ex)

At 4th level, when a kensai hits with his chosen weapon, he can spend 1 point from his arcane pool in order to maximize his weapon damage. Don’t roll for damage—the weapon deals maximum damage. This affects only the weapon’s base damage dice, not additional damage from sneak attack, magical weapon properties, spellstrike, or critical hits. If the kensai confirms a critical hit, he can instead spend 2 points from his arcane pool to increase his weapon’s critical multiplier by 1.

Lead blades

Lead blades increases the momentum and density of your melee weapons just as they strike a foe. All melee weapons you are carrying when the spell is cast deal damage as if one size category larger than they actually are. For instance, a Medium longsword normally deals 1d8 points of damage, but it would instead deal 2d6 points of damage if benefiting from lead blades (see table below). Only you can benefit from this spell. If anyone else uses one of your weapons to make an attack it deals damage as normal for its size.

[Sebastian Hirsch]

Yes, but unless you find some way to add it to your magus spell list you cant use spell combat with this spell.

[Seraph Stormborn]

You can buy a wand of Lead Blade

[AnthonyHJ]

For what it's worth, Enlarge Person is on the Magus list and gives the same increase in weapon size. I think the two spells might even stack...

Personally, were I the DM, I'd look at it this way; a large-sized creature would be doing 2d6 with a longsword and could use Perfect Strike, so it's hardly metagaming to use a spell (Enlarge Person or Leaden Blades) to achieve the same effect.

If in doubt, ask your DM whether they would allow it. If you are the DM, think about whether you feel it unbalances the player; it uses up two resources (arcane pool and a spell-slot) to achieve, so it's not something they can keep doing, and it doesn't even offer double their average damage. When you add in the strength-bonus, it's even less of a significant boost.