The Old ( as in age ) Bob Lee of the most recent books .
Young and middle aged Bob Lee favored .45acp in his 1911 's .
Hunter ages his characters pretty closely for the years the books are set . Bob Lee's age was fixed by his Millitary service , being a senior NCO in 1966 .
Even more specifically, by his birth being a plot element of Hot Springs ( featuring his father Earl ) happening in 1947 . That would be a little continuity fuzzy to make Earl a 20 y.o. Gunners Sgt in his own timeline .
But not picking on Hunter , he's still much more timeline correct than most authors of continuing series characters. Most authors that do age their characters, do so at 1/2 to 1/3 the real passage of time .
But still, the Bob Lee character didn't switch from .45 to .38 Super , and .308 to 6.5 Creed until well into his 70's .
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Within the Hunter Universe , the big gap l want to see filled , is the middle years of Carl Henderson. In Dirty White Boys set in early '90s he was drizzled over the hill OSBI LT alluding to his long history of gunfights . In Hot Springs set in 1947 training under Earl he was young rookie . There's got to be a whole series worth covering his interviening exploits .