[cpileri]

What would be the problem, from a safety standpoint, of taking a factory loaded shotshell, opening the crimp, dumping out a portion of the pellets, and closing it back up, then firing it?

Safety should be Ok, as pressure would be less right? wrong?

Dwell time in the chamber would be less, so it may be slower despite the lesser weight. No way to tell, I know.

Mostly concerned about safety only.
Can worry about effectiveness and p[atterning later.
C-

[HSMITH]

No safety concerns at all so long as the shot load is less, and you stick with lead shot without adding any filler material to make up the extra volume.

Getting a good crimp is going to be nearly impossible. Ignition without a good crimp is spotty. Pressures are going to be low, so wad sealing will not be as good as it can be, leading to further inconsistencies. All in all it is a pretty good recipe for a very poor performing shotshell. I would recommend that you buy the "extra-lite" and "extra-lite low noise" variants if you desire reduced payloads and expect decent performance.