You experienced inertial bullet pull. The firearm is so light that the recoil is pulling the bullet out of the case. This is strictly an issue with the weight of the firearm—not the ammunition—and some firearm manufacturers have a warning in the owner’s manual that addresses this issue.
Because it is designed for use with short barrels, shooting Short Barrel Personal Protection ammunition in a full-size firearm will result in a higher velocity than advertised for the load and can over-expand the bullet on impact. However, it will not damage your firearm.
Do not shoot shotshells in your suppressed firearm. The shot capsule breaks up on the rifling and you will fill the suppressor with plastic and lead shot, possibly damaging it.
When ammunition is repeatedly chambered in semi-automatic firearms—in other words, a single round is loaded and unloaded every day—it can weaken the case mouth enough to cause neck tension failure of the cartridge. Replace the top round on a regular basis to prevent this.
We recommend storing ammunition in cool and dry conditions in original packaging. For a full recommendation on storage, refer to SAAMI storage guidelines, http://www.saami.org/PDF/SAAMI_AmmoStorage.pdf.
An even better choice than standard Lawman is Lawman Clean-Fire®, which has a patented Clean-Fire primer that eliminates airborne lead, barium and antimony. Also, the TMJ bullet’s full enclosure of the lead core prevents hot gases from vaporizing lead off of the bullet base.
Look at Gold Dot® ammo. We have a 200-grain 44 Special load whose bullet was designed expressly for 44 Special velocities. It expands at velocities as low as 780 fps in our tests. That's less than most 3-inch barrels generate with this load.
That bullet dates to about 1970, when it was state-of-the-art. It was great in some guns and troublesome in others. We replaced it with a 21st century Gold Dot hollow point +P load. The new load gives more reliable expansion, more velocity, improved feeding, and better bullet integrity.
Gold Dot is loaded with premium, service-proven jacketed hollow point bullets in a nickel-plated brass case, while Lawman® is loaded with less-expensive TMJ and FMJ bullets in a standard brass case. Other than that, the attention to detail that is our hallmark is the same for both.
No. Both headspace on the case mouth. The shorter 40 S&W will not be supported in the 10mm chamber, so headspace control is lost. You'll get misfires, blown primers, deformed cases and potentially gas jetting from the action. Always use the correct ammunition for your firearm. Don't cut corners!