Ed Doonan and i built a bullet recovery box for the purpose of examining fired cast bullets. This was an all day build project with several previous weeks saving used motor oil to soak the sawdust.
Two four by eight sheets of plywood cut into four strips, scrap lumber for the frame and oiled sawdust for the filler. The entry hole was foam rubber cut into a funnel shape like a fish trap. This looked like a coffin for a fat python. The box was set on saw horses and the rifle or pistol was carefully aimed to travel through the center of the box.
The one modification after using a day was to cut slits every two feet that held waxed paper so we could see where the bullet rested. We could pull the paper up until there was no hole and then would know where to dig to retrieve the bullet.
The box worked very well. The bullets showed how they entered the rifling. The depth of engraving on one side showed if the bullet traveled askew in the barrel. With the .44 Magnum and a full load of 2400, the powder granules impressed on the base before burning. We shot a Super Black Hawk and a Marlin .44 Magnum carbine to see if the same phenomena occurred and it did.
One example was my Marlin 1895 .45-70 where the rifling marks showed the bullet traveling markedly sideways in the bore. After this revelation, I bought a .460 sizing die to only lube the bullet as-cast (.4595+) and the accuracy improved. I had been sizing the bullet .458, the slight difference helped.
As to stopping bullets, the only bullets to go the entire length (eight feet) of the box were full patch .30-'06 National Match and full power Trapdoor loads with the 500 grain round-nose Government bullet. The .45-70 load dented the end panel, the .30-'06 load stopped against the end panel. Even the Lyman 335 grain hollowpoint bullet only penetrated six feet, the heavier bullet went the distance. Most cast bullet loads, both rifle and pistol, went three to four feet.
Farm boy from Western Illinois, living in the Magical Pacific Northwest