I borrowed this idea from another member here
@Franklink, 5 gallon bucket, 2/3-1/2 full of rubber mulch. Screws or nails to hold the mulch keeper in place. Lid cut in half or to suit. Target clip at front top of bucket. This setup keeps the target backer debris in the bucket. And any rubber mulch that might leak through.
Yep, been using this method for 5 or 6 years and will continue to do so since it works so well.
Want to point out that they also nest inside of each other and can be stacked to take up less room when not in use.
I've got three in constant use and it sure makes dope work convenient. Every time I walk out to move the targets I can come back and get dope data for 3 different distances. 5 or 6 trips is actual/verified dope for 15 or 18 different distances.
They even work well as a pellet trap for Chrono sessions in the garage.
I use cardboard as the mulch retainer/target backer. The nails hold the cardboard next to the mulch and targets can also be tucked in under the nails and to keep the wind from blowing them away. Any time something comes to my house in a decent sized box I cut out cardboard circles. Simple process, set the bucket on the cardboard and "trace" around the bucket with a box/utility knife. By using the smallest circumference of the buckets taper (the base) it prevents any issues with the cardboard not fitting all the way down to the mulch.
I'll clean em out every so often, usually when they get heavy. This was the clean out that was everything from early summer until about 6 weeks ago.
I've got 8 or so of those same plastic containers of lead now, probably about 95% good soft JSB. I estimate the container above to weigh about 12pounds. I've dabbled with casting for muzzleloaders and have molds in .50, .357 and also an NOE pellet mold that drops 19.6gr .22 pellets. Emptying out the lead is pretty simple, shake shake shake. The lead goes to the bottom, the rubber mulch stay on top. Gradually remove the rubber mulch into one of the other bucket and eventually left with mostly lead. I've considered making a filter out of hardware cloth, just haven't done it yet. Anyway, lots of lead collected for potential reuse versus just getting spread all over my property.
The 5 gallon bucket pellet trap is a dirt cheap and super simple method that just works.