Like to point out that keyholing can be an indicator of a bullet that isn't completely round, tumbling as the gas blow by tips it leaving the bbl.
A bullet that isn't completely round would also allow some significant gas cutting, regardless of the base diameter...if it obturates and softens, but that .358 is immediately followed by a ring of say, .355...the gas would blow right through. Obturation is good, but it needs cold hard lead to hold that hot squishy lead back at the base of the bullet.
Often, home made alloys can be a little light on the tin content, or it can be unevenly distributed if not fluxed correctly. No tin in your cast = bullets that dont fill out the driving bands completely, as it cools too fast in the mold to reach the very ends.
Your wheel weight alloy combo, water quenched, is sufficiently hard to be pushed at any velocity you can achieve in a 9mm, as a few have pointed out.
LLA is just fine as a lube...also as many have pointed out.
With these things in mind, we're kinda down to two real possible problems, both of which are easy to check, and solve :
1. your throat is large, as many have pointed out is possible. If this is the case, you are going to need a custom mold...but you need to cast it in order to find out... I would consider doing the casting of it before ordering a 100+ dollar mold.
2. Your bullets aren't round enough. Easy fix : Get a sizer. As cast bullets are great... if the size is just right, and your alloy is perfect to allow the bullets to drop as close to perfection as your skill will allow. Hard to do for us casting Newbs, sometimes. A lee sizer is a great tool for assuring that your bullets are the perfect diameter.
Think they are falling the perfect diameter ? Put a few of your perfect bullets through a sizer, and watch the little lube catcher rings squish and become shiny on one side, and stay the same on the other.... or get shiny all around, or not size at all ( undersized as cast ) Even the best casters I know size their bullets for this reason. "Perfect" as cast bullets are a true rarity, the lee sizer is a great way to make "almost perfect" into "perfect" every time.
Given that the sizer is by far the cheapest of the solutions, and that you should have one anyway...I'd say try that route first.
But hey, thats just me ! And I don't know squat about casting....other than its a pain to sit in front of a 700 degree furnace on a hot sunny day.