I think I might have made mines a little too tall for my liking. It's at 68" including the bottom 12" that's supposed to sit in the ground.

Any pics would be appreciated since I know there are different ways to build them.

My current frame is bout 3 feet from top to bottom.  This gives me about 21" of target area, which means I can fit one 8" target, and one 12" target on my frame at the same time without overlapping the top or bottom of my frame.  I usually use those black and yellow "shoot and see" ones. The next frame I'll make I'll probably make 40" so that I can fit two 12" targets at once.

I drive a Mazda3, so I can't really make my frames much longer than that.  I think that is a good size for my applications.

You have to figure, 12" legs + 3" for the combined thickness of the two 2x2 (actual width is about 1 1/2" each) will be "unused target space".  68"-15"= 53" to place targets.  That's enough for four 12" targets stacked on each other with room to spare.

I made my first frame 6' tall. It just fit in my 6' bed of my truck. It was a little long for my taste so I built the next one 5' tall.

I made my first frame 6' tall. It just fit in my 6' bed of my truck. It was a little long for my taste so I built the next one 5' tall.

Similar.  I have a 5' bed in my new Tacoma.  So my frames are 5' top to very bottom, giving 4' of target mounting height.  I like the length. 

Good compromise between maximum target height and ease of carry, not to mention it lays flat in the truck.

For fastening, I just use 4" carriage bolts with wing nuts.  I find it much easier to just drill 8 centered holes on the ends of al my corners, and then use the bolts to secure them all together. Rather than screwing in my corners at 90 degrees.  Also gives the option of folding, or disassembling my frame if I need to. 

I buy a 8" length of 2x2 wood at city mill and have them cut it on half
that's my frame

I clamp the cardboard onto it but I may switch to velcro

Velcro? Damn u rich.$

I buy a 8" length of 2x2 wood at city mill and have them cut it on half
that's my frame

I clamp the cardboard onto it but I may switch to velcro

yeah, talula's velcro/campaign sign version was mighty impressive

Thanks for all the input guys.

I chopped off another 14" to use for spare parts in case I end up shooting it up lol. My frame now stands at about 54" total and can now fit in my car without having to put the seats down

I kinda want to chop down the 14"ers and screw them on permanently, I just hate how they stick out so much.