Whitey, I'm still looking for the reprint booklet I mentioned, but as yet, no Joy! 

Maybe somebody else has a copy of the reprint booklet that the NRA used to sell covering range building, backstops, etc and would be willing to dig it out and make a copy of the pertinent info for Whitey?  Surely I'm not the only one who ever bought it, am I?  (Maybe I am, and that's why we can't find it!  )

Froggie

I got involved in building an indoor bullet trap around 1980. The range was about 20' wide: we removed a few bricks from each side at head height and cemented in a old truck sidemember channel to run across the range, flanges facing in the direction of fire. 8' x 4' sheets of 5/8" thick steel were then laid on to the sidemember bottom flange to form an angle of 45 degrees with the ground. The plates were electric welded together and triangles of 1/4" plate were welded in to close each side. Old railway sleepers were laid along the ground and covered in 1/2 plate on the side away from the shooters: these protected the floor level strip lights. The plates weighed 747lbs each and we did well to get them into place without injury!
When first used, the bullet trap rang like an enormous bell. The back surface was then covered in old concrete paving slabs which stopped the ringing.
I now live a few hours drive away, but I paid a visit to the range in 2004 and the bullet trap has been  completely trouble free.
Fred.

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