shoot them and see results. I load 9mm with 115 and 124 grains, so 125 grain 'might' be little heavy for 380, but that does not mean they won't preform well. Try & see ??
The smaller the grain weight, the faster you can make the round go. 90 Grain bullets can reach 1,350-1,400 feet per second maximum, 147 grain bullets can only go 950- 1,000 Feet per second maximum. Assuming you're talking about bullet weight and not powder weight.
Some .40 caliber bullets are supersonic and some are not; it depends on the load. Generally lighter bullets (155 grain or less) will be supersonic, and heavier bullets (165 grain or more) will be subsonic, although there are a couple 165 grain bullets out there with advertised velocities about equal to the speed of sound. No matter what bullet you purchase, if you feel like subsonic/supersonic is a difference-maker to you, then check the manufacturer's specifications on the ammunition you're purchasing.
The correct bullets for a 223 WSSM are .224.
The .243 Win is a great, it shoots 80 to 100 grain bullets, the 7mm-08 Rem is also very good it shoots 120 to 140 grain bullets. The .243 recoil is very lite te 7mm-08 is mild with 120 grain bullets. The 243 is a great deer round.
All else being equal, heavier bullets lose velocity and trajectory faster than lighter bullets.
Generally they don't. Lighter bullets generally have a worse ballistic coefficient as compared to heavier bullets of the same caliber.
Why are you making your own 9mm bullets? What do you need 9mm bullets for? What do you even need a gun for? Jeez, just move to somewhere safe.
Grains refer to the bullets weight. A 40 grain bullet weighs four grains more than a 36 grain bullet. It's a little heavier, that's all.
Grain is a measurement of weight. There are 7000 grains to 1 pound. Bullets can weigh from as little at around 20 grains to over 750 grains. Grain is also used as a measure of weight for gun powders.
No one answer to your question. I shoot light .243 bullets for groundhogs, heavier bullets for deer. All other things being equal, the lighter bullet can be driven faster, but the heavier bullet will retain energy at long range better.
500g of ham 33 230 grain 45 cal. bullets
Grain generally refers to weight- of bullets and gunpowder. The Mossberg 45B was a caliber .22 Long Rifle firearm. .22 LR is tpically a 40 grain bullet weight cartridge.