Wrong, but closer than most things you post. Per Beretta's website, it's 11.8 empty, not 10.5; which is a difference of 12%, and so definitely closer to right than most of your statements.
https://www.beretta.com/en-us/21-a-bobcat/
And that's empty weight. Loaded with 8 rds adds another ~1 oz or so, taking it to around 14.
- Plus you claim you use an extended (Taurus) magazine, making it taller and heavier, and slightly increasing ammo weight as well.
- Plus we have to add the weight of the extended and threaded barrel.
- Plus you claim you add an additional metal plate on top of the slide.
- Plus you claim you add a dovetailed sight on that metal plate on top of the slide.
- Plus you claim you add an extended speed safety.
- Plus you claim you add a manual slide lock.
- Plus you claim you add an extractor.
- Plus we have to add the weight of a suppressor.
- Plus you claim you add a luminous sight onto the suppressor.
m21 Beretta needs steel cap added to the slide so that you have the needed metal to fit a dovetailed rear sight and the extractor. a vertical pin thru the slide retains the extractor.
...I preferred the speed safety lever and cocked and locked carry anyway. I put the luminous front sight on the can and the rear of the slide, and the sight that I dovetailed into the thread protector was just plain blued steel.
...m21 Beretta pocket .22. 7.5" OAL. needs sights, extractor, slide lock, the longer PT22 Taurus mag, speed safety...
...the SA-only, re-worked M21 Beretta as my only .22lr handgun. I'd have about $900 in it, by the time the luminous sights were fitted.
When you add the silencer to the M21, you can hunt any time and anyplace. That 9" 15 oz, 2" at 25m combo constantly entertaining on the trail. Adding the can would be another $400...
All those added items mean added weight; no way around it. I know you don't like being reminded of the laws of physics, but they're laws that simply can't be ignored anywhere other than a drug-induced fantasy.
So starting at around 14 ounces (loaded with the modified, longer Taurus magazine) before all those adds, what is the finished weight likely to be? I honestly don't know, because I've never kludged up my 21A that way.
But I do know that when you start with a gun that weighs 13.5-14 oz loaded, add all the stuff you say you add, and then add a silencer on top of everything else, you don't end up with a finished weight of 15 oz.
A 9" long, 15 oz silenced M21 .22lr Beretta AND a Sig P938, also 9 ozs, weigh no more, (both fully loaded)...
Then again, I don't think a one-pound Sig P938 weight only 9 ounces either...