a lot easier than measuring everything and reporting measures on wood pieces. Ask if you need any dimension but the easiest is to start by making the 'grooves' in the sides 2圆, and the bottom 2x4, and then slide an NRA target into it and mark other measurements from there.
It also allows to use either standard NRA '10m rifle' targets, or any printed target on 'letter' size paper (landscape direction) by the use of 2 sliding slots. No need for a router or a mitter saw like other 'complicated build' out there. Just wanted to post pictures of the one I made as it may inspire others since it is very simple, and only requires a table saw (or a circular saw if you are good with it).
I know this 'duct seal' trap idea is not new and many have done it already.
