It depends on the load
Depends on which 45 and which 44 chambering you are talking about the load
A 44 magnum is more powerful than a 45calibur
The longer case of the .44 Magnum holds more powder, and, even though the .44 is smaller in diameter, it tends to pack a heavier projectile, ranging from 240 to 350 grains, vs. the typical 165 to 235 grain projectiles used by the .45 ACP.
yes
trade it in for a 45 caliber
A 44 magnum is just the new and improved version of the 44 special which the special is a 44 caliber. Magnum just means bigger so the 44 magnum is pretty much in between 44 and 45 cal. However, if you mean size, .45 is slightly larger in diamater than .44.
No.
It depends on what you mean by bigger, but the answer to the question you're probably asking is yes. A .45 caliber bullet is .45 of an inch in diameter. A .44 caliber is .44 of an inch, so it's slightly smaller in diameter. However, .44 caliber bullets are many times longer and heavier. A common weight for .45s is 200 or 220 grain, and for .44s it's usually 240 grains.
We can't really answer that until we know WHICH 45 and which 50. In the case of a muzzleloading black powder rifle, the .50 with have more energy, all other things being equal. However, it could also compare a 50 muzzleloader to a .45-70 cartridge rifle, which is more powerful. Caliber alone only tells us the width of the bullet.
No. There was a 45
no, a 45 caliber is way more powerful than a 40 caliber Actually, it depends. The following is copied from another answer of mine: The muzzle energy from a .45 caliber round can vary between 350 to a little over 500 ft-lbs, with velocites from about 850 feet per second to over 1000 FPS. The .40 caliber round can range from about 480 to about 570 ft-lbs of energy with velocities ranging from about 1000 FPS to about 1400 FPS. So, in short, it depends on the specifications of the particular cartridges you are comparing.
As far as self defense handguns go, the .45 ACP is an extremely powerful and effective caliber, with a proven military track-record.