<< the consensus so far is that other than ballistic putty or similar, it's VERY hard to avoid fragmentation to the point of disintigration as you approach supersonic. Apparently lead dust becomes a concern. Acute angles just cause smearing, and even those with truck-mud-flap rigs report that the very high-powered air rifles still cause pellet disintegration >><br><br>Yup; that's been my experience. And heavier pellets don't fix things - plus they beat the snot out of most commercial traps. Current trap uses acute angles, dampening of the metal (reduces noise) and some baffles - and baffles add a LOT of debris inside the trap (which then needs to be cleaned out more often). As I said, I intend to replace it with an oil-washed decelerator type trap. I haven't calculated my target airflow requirements yet, but the same 12v DC power for the oil pump is going to drive a salvaged muffin fan(s), aspirating thru a HEPA filter.<br><br><< can get close to 20 meters upstairs >><br><br>As for your brilliant approach to the indoor range - Hehe - I have similar contortions to go through for longer-range indoors practice - I gave up and stick to 10 meters, which I can barely get in the walk-out basement without shooting thru more than 2 rooms. Kids who are not shooting at the time, curious dogs, etc. make it impractical to shoot farther indoors.