Just received the BBPT, it's tough, not even the USPS UPS could screw it up. Nice and solid, well constructed. Looking forward to giving it a shot tomorrow, pun intended.
Addendum: Not picking nits here just my observations for my requirements. Firstly I'm in an urban area, not on top of each other but...still. Gun, Maverick 600mm .25 with DonnyFl Moderator, 33.95 gr pellets at 900fps. Set it up at 25ish yards, This thing is light, I've got a steel trap that will stop most anything up to .308 and it's VERY HEAVY. 6 shots down towards the bottom, OH OH, not backyard friendly. Not BELL LOUD but very noticeable. Interesting thing is the pellets were pulverized, steel held up very very well. Ok what to do, well my good old standby, rubberized mulch, brought the trap in, laid it out and added about 2" of rubber mulch and layer of carpet and good old duct tape, put target on cardboard back on and put it back. A few more shots, ahhhhh much better, not as quiet as a cardboard box with the mulch but MUCH better in the bottom and 3/4 of the way up, at the top not so good, but perhaps acceptable. Next I'm going to try a mix of Flex Seal and Rubber Mulch, just to see if it'll hold up better and my Carpet/Mulch that does the job for 500 rounds or so. Later I'll try my Maverick .22 Compact.
I'm still happy with it, it's light, I can move it around as necessary and it's weather proof, well, except for the cardboard, but I can bring it in on the off chance we get rain in the next few months, not likely but it happens on occasion.