"I've ordered these a couple of times, once they only sent me a single bottle, but having put around 1400 of these rounds through a few plastic springers I got from walmart, an Co2 GBB UZI, a Co2 VSR-10, a paintball pistol, and a Co2 M84 I would not suggest using these in any gun with a tighter barrel than a 6.06mm barrel or so, as the seams on these bbs are rather large and can stick and rupture in either the loading mechanism, the hop-up, or the barrel.
I haven't had many problems with magazines jamming with them aside from a double to single stack mag with a tight output, and in the cheap pistols the quality is so low the seams don't matter.
That said, even the low power (~350FPS) walmart pistols ruptured the paintballs on contact with a hard surface.
Similarly, the VSR-10 had no jamming issues, although a couple broke when it shot and splattered paint out the barrel. The bbs that did survive were traveling at around ~600FPS when they impacted, and obviously splattered.
The UZI managed to fire a full mag, but like the sniper rifle it was splattering paint out the chamber and the barrel. All of the bbs splattered without issue.
The 17.65mm paintball pistol (with wadding placed behind and in front of about 20 6mm paintballs) broke every paintball with a grouping of around four feet at around twenty, so it's clear that the bbs don't need to be moving that fast to rupture.
In general, I noticed the groupings to be rather poor (around a sq foot at twenty), and the bbs are somewhat light, so they're easily affected by wind.
Regardless, they're incredibly fun to shoot, break with good consistency, and hurt in a gnarly fashion, considering the shell on the bb shatters. I would highly suggest purchasing them regardless of their poor manufacturing quality simply because they're a highly entertaining novelty item and would work great for CQB with cheap guns.
"These DO NOT WORK in a revolver, and 1 out of 10 was too big and jammed my sniper magazine. However, even though it says not recommended for AEG, out of 300 rds, 0 BROKE! These are a good product if you have the right gun.