If the metal pipe when tight enters the compression fitting at the angle shown in the second picture, it probably has stress on it that is not allowing the compression ring to squish it properly.
Make sure, assuming you can take another whack at it, that all obstructions are cleared. Example, if the lower hose is not allowing the upper hose to seat properly, pivot it a bit to clear. You understand what I am getting at. Have to give the fitting a fair chance to do it's job.
Frankly, I like Jack Stands idea of getting a robust fitting on the end. A real and for true one. Looks like you can use a little extra length on that end anyways for added clearance.
Regarding a vacuum, it is never mandatory to pull a vacuum before recharging, EDIT - Scratch the previous sentence YOU CAN ENTER REFRIGERANT INTO YOUR SYSTEM WITHOUT PULLING A VACUUM, but you are not eliminating moisture that has crept into the system. Even the el-cheapo air compressor driven vacuum pump from Harbor Freight is WAY better than nothing.
As noted by brighton, spring the $60 for a new R/D. I would almost like to see you replace the RD without pulling a vacuum, than pull a knarly vacuum with an old worthless R/D. Do both though. :-)
Decent vacuum pumps are available at HF for $100 and you can get a nice Robinaire for $200-ish if you sniff around.
Electric Vacuum Pump - 2.5 CFM
Here is the el-cheapo
Vacuum Pump - AC Vacuum Pump w/ R134A & R12 Connectors
I think you need gauges to pull a vacuum.
Look at the bright side, you can get the medium (electric - $89) HF pump, gauges and R/D for the cost of an AC shop recharge.
AC Gauges - Save on this AC Manifold Gauge Set
One final note. You can buy a 30 pound tank of R134A at the local parts store for $100. That is equal to almost forty 12 ounce cans that sell for $15 a piece as you have a little line loss from transfer into your system.
You could be the AC God of your neighborhood.