Re: Range Design
A lot of the design considerations will come down to what is surrounding your property...what is downrange?
My property is about like yours, 15.3 acres. From my fixed bench I put up 8ft berms (the limit with my loader) at 100 yds and 300 yds. From a portable bench set up in my driveway, I can get 400 yds. But I don't do that often as the noise is triple for the neighbors when I do that vs from the 300yd bench. Of course I let most of them come use the range so they don't care too much.
Behind the backstop is ~1.5 miles of clear, open fields. Not my property, but nothing to hit. I do not shoot when farmers are in the fields. I strive to make sure that despite that buffer, all of my rounds end up in the berms. I do NOT want anything leaving my personal property. When the state boy brought out an auto M16 we shot it in full auto only from close range at the bottom of the berm.
I've been building up a supply of old tires from the local auto shop...every couple weeks I swing by and load up the pickup. I plan to add about 4-5 ft of tires, two overlapping rows, to the top of my berms. This should make it virtually impossible for a round to leave my range.
I am building another range with the shooting position inside a climate-conditioned enclosure within my barn. One backstop at 30yds for pistol, one at 320 yds for rifle. Both backstops will be 8-9ft of double-row, overlapping tires filled with dirt.
If you have anything within a meaningful distance behind your range, you may need to go even more overboard.