Artillery carriage for springer - experiment

[WhatUPSbox?]

In the past I remember threads on things like paint roller supports for better artillery hold with springers. More recently the suggestion was to use a drawer slide and then the suggestion was to use the cheap linear rails from china (sorry, I forgot who suggested it). I have some of these but didn't want to mod them for this, and then I saw a linear rail on Thingiverse that uses BB's for bearings.
https://www.thingiverse.com/thing:2847294

I thought this might work, especially since you can mod the shape of the parts into grips, mounts, etc. The only mod I made was to shorten the rail to 140 mm (from 220) so it would fit. The models printed fine (check the units match for all the parts), took all day, I printed PLA at .16mm, no supports. The carriage part prints vertically so the BB grooves have a texture. I wrapped some sandpaper around a bamboo skewer to smooth it out.
I had some old, low cost Crosman BB's whose size varied. I tried to pick a common size and then had to use one less in each channel to get easier motion. Overall it moved freely and did not have side play. Probably getting better BB's (Daisy?) would smooth out the motion a little more.

I don't have a much springer experience but I do have a stock Quest 1000 (.177) that is a good test piece. I attached the rail to the underside of the Quest with some strong double sided tape and shot some at 11 yds. Shots were on a bag, on a box, on a lightweight table.

Does it work? Who knows. I'm not good enough with a springer for this to be a definitive test. On the other hand, it was a fun print. If someone was more serious, shaping the top of the rail to match the stock and shaping the carriage into a grip would be easy mods.

I did find out the Quest seemed to like the Supermags (first time try) and I may try some tuning and learn to shoot it.

Note: if you print this and are loading it with BB's, the final close-out benefits from a piece of paper to retain the BB's, and then is slid out.