Unless you make your own amo...
1000 rounds a month at ~5 cents a piece (.45 ACP) adds up over the years. Not to mention the time to actually load the rounds. If you cast your own bullets it is not much cheaper but takes even more time.
For each weapon , say 9mm, .45 ACP, plus rifle rounds puts it at ~$150 a month plus range fees (gas for road trips to the 'open spaces') targets, safety gear (it wears out you know), gunsmithing plus time to load up the rounds. Not for the faint of wallet or short of timers.
After a couple of months, or so, dedicated practice single ragged holes at 10-15 feet is not so tough for 6 rounds (unless your weapon is worn). Under stress and return fire ... I'm guessing not so easy but I have yet to try that out. Should only take one on target to get the job done.
Private digs, plentiful cash and abundant leisure time helps considerably in most any pursuit. In my younger days living on the posse ranch (free shooting range) and all the .22 LR I could use I got real good real quick shooting ~500 rds per day for a summer. I was required to clear the grounds of ground squirrels and I dare say the population still has not recovered 30 years hence. Any squirrel that caught my attention and was still for 3 seconds did not make it another day.