Hello everyone. I know how to reload ammo but I lack certain mathematical concepts that are needed to work a load backwards from projected performance. I know you lot can be pretty smart so can you help me? I want to find chamber pressure. The cartridge in question is 7.62x25.Case:>7.62x25Bullet weight:>265 grainsVelocity:>1000 fpsI want 300blk but smaller and dumber.
>>64685651You know you could seat the same bullet further back in a .300 BLK case and have the same OAL, right? And that 7.62x25 has the same case head so you can't fit more of them in a magazine?
>>64685660I didn't know that. Thank you
>>64685660Wait a second, I forgot to add, I need to find chamber pressure so I can calculate bolt weight. Thats what I want. I appologise for not including that in my beginning post
You cannot derive the answer from the variables presented.
>>64685744What more do I need?
>>64685651but why tho
>>64685651What is barrel length?
>>6468586512"
>>64685651Get Quickload or GRT software and plug your numbers in.
>>64685673There isn't just one chamber pressure involved, there are infinite different pressure curves that could give the performance you specified.
>>64685673 Checking I understand you: You want to scratch-build a blowback semiauto, correct? If you would: Please state what you hope to make. Toolmaking Step One = Imagine what you want. Describe it in English.
>>64685899>>64685893For example, here's a list of loads Quickload generated. You can see the max pressure on this chart but that alone is not enough for doing any sort of design calculations. You can easily model the individual loads suggested here.
>>64685905>Please state what you hope to makeOP wants to make a super cool armor piercing subsonic gun. He picked the Tok cartridge to start with because he heard it had decent armor penetration, but he's not smart enough to realize that is only because of velocity, which is out the window for his *subsonic* project.
