Grain Count?

[Vlad G 345]

Ok think of bullet weight and powder weight as the weight of your car and the power of its engine. You can have a big old car with a 80hp engine, and you can have a small car with a very powerful engine or any other combination. The car is your bullet, the powder is your engine. If you want to drive a bigger car faster you need a bigger engine, if you want to drive a smaller car just as fast you can get away with a smaller engine.

 

Where this analogy breaks down is that if you put TOO much engine for the weight of car, the car might explode. Because the the heavier bullets have higher inertia, they are a bit slower to get going so the they don't make as much room for the powder gases to expend as quickly leading to higher pressures. Also heavier bullets are also normally longer, take more of the case volume resulting in even less space for the gasses to expand and hence more pressure. To much pressure and things go boom the wrong way.

 

When you see a recipe for a load such "max load for 115gr bullet of this SPECIFIC shape is x.x grains of some powder" you also will see "and the C.A.O.L is 1.xx inches. Basically any load data that doesn't specify how far the bullet pokes out of the case is worthless, seat the bullet too deep, you have to much pressure and say hello to Mr Handgrenade

[KpdPipes 388]

Is there any difference in perceived recoil based on bullet weight?

 

Somewhat..it isnt as pronounced as it is with Rifles, but the difference is there. There are several factors, there is the weight of the projectile, and the Weight/type of Powder. Heavier bullet with a Lighter powder charge will probably have less recoil, than say a lighter bullet and a Heavier charge to drive up velocity..it's all a balancing act. That said, Heavier bullet doesnt ALWAYS mean Heavier recoil.... For example, there is a noticable difference in my .45 between my Practice/Match Ammo, (230 Gr Standard Ball at around 840 FPS at the muzzle) and my Carry Ammo, which is Magtech First Defense (165 Gr SCHP at 1150 Fps at the Muzzle)..the Magtech Recoil is "Sharper" than the Ball ammo..the ball has a "Push" feel to it, where the HP's have a "Snap" feel if that makes any sense.

[JackDaWack 2,895]

Force = Mass x Acceleration

Was someone sleeping during physics class?

[JackDaWack 2,895]

So does the grain count for the bullet affect the amount of grains of powder in the cartridge? Or is it generally the same?

Absolutely if your using the same powder. If you take a look at load data, powder charges vary based on bullet weight. Lighter bullets tend to use less powder, middle weight use slightly more, and heavier bullets use less. You kinda see a peak in the middle weight range. This is from max and min charges, and factory ammo. anything is possible with your own recipe, but load data seems to reflect this trend.

[Vlad G 345]

So does the grain count for the bullet affect the amount of grains of powder in the cartridge? Or is it generally the same?

 

Yes, no, maybe. There are too many variables.

 

If you had a lighter bullet and a heavier bullet and you wanted to drive them both at the same speed with the same powder you would need to use more powder. On the other hand normally speaking heavier bullets are actually launched moving slower then lighter bullets so they might not need extra powder to make that slower velocity. On the THIRD hand heavier bullets are longer, take up more of the case space which means there is less room for powder and more importantly less room for the powder to burn in hence resulting into unsafe pressures so may be that heavier bullet has less powder behind it then the lighter one.

 

And then there is the forth hand of course, which says you might not even use the same powder behind the two bullets. Some powders are more suited for lighter bullets some are more suited for heavy bullets, and x grains of one powder have nothing to do y grains of a different powder, there I are all very different.

 

This is why people who reload often have a couple of heavy books linking all the safe combinations, and then crosscheck that with the data from the component manufacturers websites.

[Larry1851 0]

Hickock45, on Youtube, recently posted a video about "grains" as it relates to bullet weight, amount of charge in the cartrisge and oxygen ratios, etc. I found it very helpful. Your mileage may vary...

 

[dgstinner 11]

+1 on Hickok45's video.

 

 

Sent from my iPad using Tapatalk

[JLHockeyKnight 0]

jackdawack & Vlad G,

 

Thanks for the replies. I guess I try to think of this when you compare a 9mm & .45 ACP.

 

9mm has less mass & travels at a higher velocity than a .45 ACP. Kind of explains why people argue the .45 has more "knock down power" because the .45 ACP is a higher mass bullet which is fired at a slower velocity (I believe it's closer to roughly 900 ft/s vs. 1100 ft/s for 9mm). So many argue the "knock down power" is more because the bullet for the .45 ACP likely won't penetrate the target, thus the target absorbs all the energy of the round, thus likely "knocking them down." 9mm is a faster speed and less mass (smaller bullet) so it will be more likely to pass right through the target, thus not all of the energy will be absorbed by the target.

 

I hope I generally got that right.

[JackDaWack 2,895]

In a nut shell, yeah. But that has more to do with bullet dynamics. It's not over penetrating that is the issue, its how much actual damage a bullet does while traveling through an object, and how fast you can project the bullet safely and accurately. But this is just scratching the surface.

 

Powder is a very tricky subject tho. You could potentially load the same amount of powder of the same powder for both 9mm and .45 with good results, titegroup comes to mind. and were talking about 100gn difference in bullet weight. More powder doesn't always mean faster either, remember pressure is the biggest limiting factor.

 

To really answer your question, factory ammo is loaded based on pressure and FPS +p and +p+ loads. They are hotter loads, and are always loaded based on bullet weight. My HD round is a 230gn .45JHP +p, i don't know what powder it uses, but it has higher then normal pressure in comparison to a standard 230gn JHP from the same manufacture. Hotter loads can be dangerous tho, and it would be a good idea to make sure what ever your using can handle it. Most firearms can shoot +p and some +P+, revolver more so, but continuous use can and prob will wear your gun out. Unless your loading your own ammo, you can only read the manufactures specs on the cartridge, you generally don't look at what powder and how much. Companies will also vary specs on standard +p and +P+ loads since they all use different powders to hit a general mark in terms of pressure and fps.