Bullet Weight Load Differences

[Saggitar]

IM new to reloading & have tons of questions but I will start with thie one-

Can anyone explain this one to me:

On my 357 loads, the Hodgsons Cartridge Load Data Sheet says to load---Just an Example:

125 gr Hornady XTP 6.8gr to 7.5gr (Titegroup)

158 gr Hornady XTP 5.4gr to 6.1gr (Titegroup)

Now for the Dummy Question of the evening:

Why doe's it take more powder to push a smaller grain bullet? Thanks

 

[Saggitar]

IM new to reloading & have tons of questions but I will start with thie one-

Can anyone explain this one to me:

On my 357 loads, the Hodgsons Cartridge Load Data Sheet says to load---Just an Example:

125 gr Hornady XTP 6.8gr to 7.5gr (Titegroup)

158 gr Hornady XTP 5.4gr to 6.1gr (Titegroup)

Now for the Dummy Question of the evening:

Why doe's it take more powder to push a smaller grain bullet? Thanks

 

[john traveler]

The single biggest limiting factor in handloading cartridges is chamber pressure.

A lighter weight bullet, nominally of shorter length than a heavier bullet, will occupy less space in the cartridge case. That extra space translates into less pressure if the same powder charge is used as for the heavier one. Therefore, a larger powder charge is needed to achieve the same chamber pressure as for the heavier bullet.

 

[Saggitar]

Thats what I like about this forum--- short sweet answers to the problem. Good concise answer John, Thanks

 

[Spotteddog]

And you may well have asked one of the few questions possible when it comes to reloading, that could be answered concisely too! 99.9% of the rest of them are likely going to take 3 pages of responses. Half of which of course, will be opinion(s). Nearly none of which, can be decided with finality. Why you may ask?
Because that's the fun part!

 

[Snapping Twig]

Also, a lighter bullet has the potential to move at a higher velocity. For this reason additionally, larger powder charges are used.

Take for example a charge of say 4 grains of W231 under a 125g and a 148g bullet in a 38spl case.

In each case the charge is identical, however the 125g bullet will move faster for the given powder weight.

My point, there is an overlap area where once basic pressure criteria are met and it becomes an issue of speed vs mass for intended results.

 

[Saggitar]

Thanks for the explanations guys, It all is helpfull to a Rookie like me. Any other bits of hard learned lessons that you guys have learned over the years regarding handloading would be highly appreciated. Im totally ADDICTED to this new endeavor & because of the nature of it & it's possible consequences I think I can avoide critical mistakes with all your'e help. Thanks again--NEVADA ROOKIE

 

[Steve C]

All loads are limited by pressure and the loads with lighter bullets will have the same peak pressure as a load with a heavier bullet.

It isn't that it takes more powder to move a lighter bullet it is that you CAN use more powder with a lighter bullet and achieve higher velocities with the same pressure.

 

[Skip Sackett]

As others have said more eloquently than I will, pressure.

Pressure is the limiting factor in any cartridge. If I have a lighter bullet I can drive it to higher velocities with the same pressure that it takes to drive a heavier bullet slower.

I hope that makes sense. Velocity isn't usually the limiting factor. There are some exceptions. Drive a .224 bullet too fast and you will get it to disintegrate when it leaves the barrel.

Not the usual limiting factor though, pressure is.