Results: mild recoil (gas autoloading must be doing its job, given the nearly 600gr slug at 1200fps), excellent accuracy. Four shot groups at 25 yards are all less than the slug diameter in size, working out to about 2.4MOA — and that’s with just a red dot! Without rifling, from a bead sighted maverick 88, the groups are around 3-4″, some of it coming from variable sighting.
When properly loaded, this load cycles SX3 just fine. My sample pack had four squibs out of ten, which was a novel experience. The primer did push the slug downrange and the projectile even hit the 25 yards target, though a foot low. I will be testing much larger quantities of the slug from actual production (mine were pre-production samples) before I can recommend it for reliability, but accuracy in rifled bores is stellar.
By contrast, Teamneverquit slugs (1 oz, 1200fps) were not quite as accurate from rifled bore — 1.5″ at 25 yards — but had no variation between rounds. Rifled chokes gave similar results, smoothbore around 3-4″, same as TSR. Recoil, at least from SX3, was minimal.
Overall, if I had to pick a tube-fed defensive rifle, the SX3 would be the top contender. It’s light, handy, has minimal felt recoil, and serves 12ga bullets that expand to 1.5″ (Team Neverquit) or 2.6″ (TSR). I do wonder if the magazine tube could be extended past 4-shot capacity — 6 total would be nice, but I am not sure if that would compromise the currently excellent balance.