For 2230 a magnum primer may help. So can just deburring flash holes, IME. Spherical propellants are just harder to light up consistently, especially when case fill is poor, as in your situation. This article
I started with your load in QuickLOAD and found that if I increased the case water overflow capacity to 44.8 grains (fired capacity) I get 81.4% case fill with 34 grains of 2230, 3555 fps from a 26" tube and 1.096 ms of barrel time. Usually a sweet spot will correspond well to some particular barrel time, even across different powders.
Switching to 4064 I get 34.2 grains giving me the 1.094 ms barrel time (as close as I can adjust it without going to hundredths of a grain). It's a lower bulk density powder, so you get a much better 92.9% case fill. You have to settle for a slightly slower 3535 fps MV, but that's within your current velocity SD. Your particular lot of powder may differ from average, but if you adjust the charge to match that velocity, you barrel time should be a very close match to what you were getting with 2230.
I'd expect this load to have lower velocity spread because of the case fill and good ignition characteristics. Be aware that stick powders sometimes produce best consistency when dispensed to the same case fill percentage rather than the exact same weight from one charge to the next. The JDS Quick Measure is best for this with stick powders, IME, but isn't inexpensive. The inexpensive Lee Perfect measure does surprisingly well with stick powders and would be my next choice.