Depends on the size of the BBs and the weight of the shot. I.E. A 12 gauge 2 3/4" target load that has 3/8 oz shot in #7's will have over 200 BBS while a goose load in a 12 gauge 3 1/2" shotshell with BBBs will have more like 20 or so BBs
What are you asking?
6mm of either .12 or .20 gram bbs. 6mm of either .12 or .20 gram bbs.
never use .12 bbs. they are very inaccurate. Buy some .20 tsd tactical bbs, never use crosman
12 gauge is thicker than 14 gauge.
The 16-gauge (Note how it's spelled) shotgun shell will hold slightly fewer pellets (small BBs). It will have slightly less recoil, but the difference will be so small that you might not notice it. Some 16 gauge shotguns are built lighter and smaller than the 12-gauge versions, but that is not always true. And you should know that today 16 gauge ammunition is less common than either 12 or 20 gauge. 30 or 50 years ago, 16 gauge was very popular but now it is getting rare.
The stinger p9 is good with .12 gram airsoft BBs or you can use .25 gram bbs but then it will decrease the range.
Airsoft does not have gauges (those are for actual shot-guns) but BB's do come in sizes. The sizes are known in mm (mili-meters) and they range anywhere from .12 to about .48
Do a web search on "12 gauge ammunition types" Over a dozen.
Yes. .12 grams is the weight of the BB, not the size. Almost all airsoft guns use 6mm BBs. .20 gram BBs are heavier and reduce distance and velocity, but increase accuracy. .12 gram BBs will fire with more velocity, but there will be more spin on the BB and less accuracy.
No. .12 is the cheapest bbs. They have the least pain to the hit, the least length to the hit, are more vulnerable to swerving from wind, and cause the most errors and jams in your gun. All professional grade bbs are at least .2 or .25. I highly recommend getting at least .20, not .12.
As many as the magazine will hold.