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Looking through loading data, I often see separate data listed for plated bullets, but not always. There are some interesting differences that I'm trying to understand.
For example, Berry's says the max MV for their 9mm 124g round nose bullet is 1,250 fps.
OK, so I bust open one of my reloading manuals (Modern Reloading) and for 124 gr *jacketed* bullet and HP-38, it lists a min load/MV of 3.9/920 and max load/MV of 4.4/1,037 (both well within the 1,250 fps limit stipulated by Berry's). It also says a min OAL of 1.150
Now if I drop down the page to "124 Grain Copper Plated" there is no load data listed for either HP-38 or W231. Hmm... (why?)
So I go back up and check to see if there is a common powder for both bullet types so I can compare the load data and find v-N350 (which I don't possess and have never used)
For the jacketed bullet it lists a max load of 5.7 grains and 1,237 fps muzzle velocity (still within the Berry's limit) with a min OAL of 1.142 but the max load for the "plated" bullet is 5.9 grains of v-N350 and a MV of 1,196. The min OAL is the same.
Some questions:
1. Why is HP-38/W231 not listed for copper plated bullets?
A: Because not everyone has tested them out. Publishers would LOVE to have load data for all of the loads out there, but they simply have NOT shot it all...
2. I'm assuming the min OAL has to do with the physical dimensions of the powder grains and how much volume they take up, so the different min OAL ensures that the load is not over compressed when using different powders
A: Sure kinda... Min OAL refers to the overall cartridge length typically and that relates to power by meaning that you need a specific amount of powder and a specific amount of air. Most powders want between x and y of space so they can ignite and build pressure. The shorter your cartridge OAL the higher in pressure it can build up when you shoot it and THAT could be bad if it exceeds your pressure rating of the gun you are shooting it from.
3. Why is the mv on the plated bullet less than the jacketed bullet, yet the powder charge higher? (are copper plated bullets somehow more "slippery" than plated ones?)
A: Because there is nothing to the plating bullet. The plating is there to cover the lead and prevent leading, but it is still there, Imagine plating as a latex suit and a copper jacket is a parka. Which gives you more protection in the snow if you are playing around? See the image below.
Thanks - I've reloaded before, but never paid this much attention to all the data (I was younger and had a shorter attention span, I guess). Its interesting to try to figure this stuff out.
For example, Berry's says the max MV for their 9mm 124g round nose bullet is 1,250 fps.
OK, so I bust open one of my reloading manuals (Modern Reloading) and for 124 gr *jacketed* bullet and HP-38, it lists a min load/MV of 3.9/920 and max load/MV of 4.4/1,037 (both well within the 1,250 fps limit stipulated by Berry's). It also says a min OAL of 1.150
Now if I drop down the page to "124 Grain Copper Plated" there is no load data listed for either HP-38 or W231. Hmm... (why?)
So I go back up and check to see if there is a common powder for both bullet types so I can compare the load data and find v-N350 (which I don't possess and have never used)
For the jacketed bullet it lists a max load of 5.7 grains and 1,237 fps muzzle velocity (still within the Berry's limit) with a min OAL of 1.142 but the max load for the "plated" bullet is 5.9 grains of v-N350 and a MV of 1,196. The min OAL is the same.
Some questions:
1. Why is HP-38/W231 not listed for copper plated bullets?
A: Because not everyone has tested them out. Publishers would LOVE to have load data for all of the loads out there, but they simply have NOT shot it all...
2. I'm assuming the min OAL has to do with the physical dimensions of the powder grains and how much volume they take up, so the different min OAL ensures that the load is not over compressed when using different powders
A: Sure kinda... Min OAL refers to the overall cartridge length typically and that relates to power by meaning that you need a specific amount of powder and a specific amount of air. Most powders want between x and y of space so they can ignite and build pressure. The shorter your cartridge OAL the higher in pressure it can build up when you shoot it and THAT could be bad if it exceeds your pressure rating of the gun you are shooting it from.
3. Why is the mv on the plated bullet less than the jacketed bullet, yet the powder charge higher? (are copper plated bullets somehow more "slippery" than plated ones?)
A: Because there is nothing to the plating bullet. The plating is there to cover the lead and prevent leading, but it is still there, Imagine plating as a latex suit and a copper jacket is a parka. Which gives you more protection in the snow if you are playing around? See the image below.
Thanks - I've reloaded before, but never paid this much attention to all the data (I was younger and had a shorter attention span, I guess). Its interesting to try to figure this stuff out.
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