I just ordered the Ultra Flate Plus Co2 dispenser. I have the small dispenser that only accepts threaded cartridges. I am getting tired of buying the expensive threaded 16 g carts. So my theory is that with this new dispensor, i will be able to use the mini pump to pump up to about 30 lbs or so, and then use some of those cheap threadless cartridges for air rifles available at Walmart. Anyone else do this?

I am pretty new to the road, and always just used mini pumps on my MTB's. I have to use the mini on my road bike to make the tube take shape so i can insert it anyway. Why not just pump it up a little with the minipump and then top it off with the cheap threadless carts?