Meaning of grains?

I understand that grains does not refer to actual grains of powder, but what I don't get is how a 44 mag. Lever action cartridge can have 300 grains, while the much larger 300 win mag can have 180 grains. Can someone educate me?

Grains are a antiquated measurement of weight. There are 7000gr/lb. Not really sure who's measurement it was, but drams a ottoman scale weighs powder charges in shotgun shells.

Seems your referring to grain weight of projectile in the two calibers. Both very standard for each respectively. Usually 44mag will be a short, fat, round or flat nose....bore .429. Whereas the 300mag bullet will usually be a long sleek copper jacketed Spitzer, with either a exposed soft point or plastic tip...bore .308

Powder charge for 44 magwould be in the range of 25-30 gr, depending on powder. The 300win is pushed by about 75-80 gr powder. Each very different burn rates. Use pistol powder in rifle cartridges, much too fast, probably resulting in blowing up the gun.

I think what you are looking at are bullet weights, not case capacity in grains.
The 44 shoots a heavy bullet at a lower velocity.(around 1000fps)
Around 20 grains of pistol powder would be used in the 44. with a 300gr bullet
About 70 grains of rifle powder would be used to send a 180gr bullet down range out of the 300 win mag. ( 2900+ fps)
Hope this helps.

As mentioned above, the 300gr in a 44mag and 180gr in a 300win mag is bullet weight. Generally speaking larger bore diameters use heavier bullets, hence the 44mag with its bigger bore diameter uses a heavier bullet than the 30cal 300win mag.

bearslayer56 said:

... I don't get is how a 44 mag. Lever action cartridge can have 300 grains, while the much larger 300 win mag can have 180 grains. Can someone educate me?

Click to expand...

The calibre of a cartridge refers to bullet diameter. In that context, .30" is not larger than .44", it is considerably smaller.

https://en.wikipedia.org/wiki/Grain_(unit) it's part of the avoirdupois system of measurement, other posters have covered the mixup pretty well.

BattleRife said:

The calibre of a cartridge refers to bullet diameter. In that context, .30" is not larger than .44", it is considerably smaller.

Click to expand...

And to make things more confusing 44 mag isn't even .44" lol

Although by larger I assume he means the size of the cartridge case not the bore diameter.

In addition to what others have said 300WM is a bottleneck cartridge and 44MAG is a straight walled cartridge

bearslayer56 said:

I understand that grains does not refer to actual grains of powder, but what I don't get is how a 44 mag. Lever action cartridge can have 300 grains, while the much larger 300 win mag can have 180 grains. Can someone educate me?

Click to expand...

Grains are a measurement used in weighing bullets and powder.

There are 7000 grains to one pound...