Shot the 358429 for decades, I have/cast/use the standard 358429 mold along with the 358439 hp mold and the extremely rare 358431 hb mold.
As others have stated, 7.0gr of unique is the magic # you're looking for.
An older Lyman manual from 1967. Has allot of good info/reading in it. It still has info on the older molds and reloading tools. Hence: the last of an era/2 generations. In that manual they list 7.0gr of unique/358429 as their most accurate load.
http://castpics.net/LoadData/OM/Lyman44.pdf
Most manuals aren't what they used to be, a link to the last great Alliant manual. It's a 2005 manual that shows a ton of different pistol loads. Starting in 2008 Alliant changed their manual format to what you see now, no bbl lengths/no pressures/only 2 or 3 bullets listed for a caliber load.
http://castpics.net/LoadData/Freebies/RM/Alliant/Alliant_2005.pdf
Another old Lyman manual, from 1951. Another source for info that is long gone.
http://castpics.net/LoadData/OM/IdealHandbook38.pdf
Personally, I like the older manuals, allot of what they say and did can be used to this day. I swage allot of my own bullets, jacketed & lead. There's no manuals to look up oals or loads. But every reloader has the ability to measure how deep a bullet goes into a case and compare that depth to known bullets. The oals are the easiest to figure out, a plunk test or seeing if they extend out the cylinders is simple enough.
Why the seating depth is important to measure and understand with a bullet that you have no data for:
In that link to the 2005 alliant manual if you look at the simple (countless 1,000,000's have been shot) there's a load for the 148gr lwc. The 2.7gr (target load) lists 14,600psi. Same case/primer/bullet/case/test bbl/etc with a 2.8gr load lists 15.900psi. Fast burning powders tend have more issues than slower powders. There's allot of kaboom talk with the 9mm/40s&w's. 1st thing I think when I hear or see a thread about a kaboom is titegroup. Bullseye used to be the bad boy on the block so alliant put this out decades ago.
Ramshot realized the same thing and puts this in their reloading manuals about their fastest burning powder zip.
Why write all this???
Knowledge is a good thing, the more a reloader learns the better they become.
Something else to look at:
If you can recover some of the bullets from your loads/test loads. This will tell you allot about your load/alloy/lube combo.
You're looking for bullet slump/compression. The photo above (not mine) was sent to be from a fellow shooter/reloader. We were discussing bullet slump at the lube groove and how it affects accuracy. Those are "keith" style bullets (358429 is a keith bullet) with rounded and square lube grooves. Look at the height of the unfired bullet's lube groove and then the recovered bullets compressed lube grooves. Same firearm/shooter/caster & alloy on the same day/lube/etc, the only difference is the amount the lube groove compressed/failed.
Chronographs are a beautiful thing!!!!. Not sure about a load? I always set the chronograph up and run some test loads of a know load to make sure it's working properly and then run the test loads. Chronographs will help, if you get 1400fps with your 1st shot you might want to rethink your loads. They will also aid in telling you how position sensitive you load is. Simply point the firearm up before every shot and run a test string. Then point the firearm down before every shot.
Reading your brass is always good. Look for suite on 1 side of the case only, that ='s lite load/barely sealed the cylinders. Test different crimps, it's a real eye opener. The chronograph will pick up on lite/weak crimps as will your targets.
Anyway, just throwing it out there.
Enjoy your 358429/357 combo
. For some reason I feel certain that I've seen Unique data somewhere 
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