Ian,
I figured out the 18" rule in 1976, thank goodness, making my first real bench. I had used several 24 or deeper benches and you nailed it
exaclty....excess depth is wasted, collects too much junk.
I wasn't poor as a child, but four years of college and two more of grad school and then three years working and two off (planned) put the
"keep anything you could possibly use or trade with" thing you were talking about into my head pretty solidly. Trying to get past it now. In college
I was fortunate enough to have tuition, dorm and meal plan paid by my parents. Never asked for another cent. My mother told me decades
later that they were surprised. My younger sister hit them up for extra money every couple of weeks. I worked jobs during school and summers
to get stuff. Lived on $3200/year in grad school, plus a bit from mechanic work I did for people. Tight times. I remember pulling the rings
off a junkyard VW engine to put in mine because a new cylinder and piston set was $80, and the used rings went for $10, got me two years
down the road with a lot less oil burn than before. Just got to be a real cheapskate. Slowly, slowly getting past that.
Cleaned out a huge number of used targets today. They had only been shot a little......and pasted, or could be pasted, ghhaaaaa! Thinned
down to only unshot targets. Will buy more if I need them, only pasting targets during one range session, and only once per target. Throw them
out when done.......hand shaking.....
Got a lot of junk mixed brass that is only good for plinking, not for any real accuracy. Need to find someone else to pass a lot of it on to, once I
get it sorted out.
You are doing it way earlier than I figured it out.
Bill