First off, I would not use a powder that fast, especially with a heavy bullet, but for whatever the reason, you obviously do not have enough pressure to consistently cycle the gun.
It might be that you simply need to (taper) crimp as has been discussed........if your cases are black around the mouth, that would be an indication of leakage.
I would strongly advise a somewhat slower powder as well.......there are a lot of good choices, unfortunately, the availability today is very poor.
I do not go any faster than Bullseye/SOLO 1000 in a 45 ACP; PowerPistol is about optimum, IMO, & I like a FIRM crimp.
Here is a burn rate chart showing VV powders compared to various others.
(PowerPistol is not on the chart, but it is very close to Unique.)
MM
VV Burn Rate Chart 
