John in WI
08-02-2022, 08:10 PM
Before I start, the ultimate plan is to pressure test the loads prior to firing them. I'm a relative newbie, and by no means am I confident in safely making my own recipe.
I found some new, primed Cheddite 2.75" hulls. From BPI I ordered gas seals, fiber wads (1/2"), cork (I think it was 1/8"), and overshot cards. I already have #F (0.22") and #1 (0.30") hard cast lead balls that I made years back. It was WW with a big dose of lino.
I cannot find recipes for these components, so I want to create my own. I have a bunch of Unique, and a bunch of International.
For plastic wads, with unique and a 3/4oz payload, 15gr gives around 9000psi and close to 1200fps. Am I safe in assuming that with 3/4oz, but using a gas seal and fiber, the pressure would still be safely below the pressure limit? Ie, if it's higher, it would still be safe?
Likewise for International, 12.5gr gives around 1200fps and 9600psi with plastic wads. If I work them up with 12.5gr, the fiber wad/gas seal substitution would presumably be below 12000psi?
How do people generally go about pressure testing? It's not cheap, so I think I would prefer to try and make a good guess to begin with, and hopefully verify the guess with data. Would it be smarter to push it a little bit, and try to figure out what's the maximum I could safely do, and then dial it back from there?
My goal is to make a low recoil round mostly for shooting paper and jugs. Maybe a 3/4oz close up coyote load from the 0.22" balls.
I just want to make sure I'd send the tester something that's safe on their end as well. It's concerning, from reading a lot of reloading data, how something like a wad change can add 2000psi. I had no idea it was that touchy! (which is why I have never deviated from a published recipe). Thanks for any ideas. This is my first go at it.
I found some new, primed Cheddite 2.75" hulls. From BPI I ordered gas seals, fiber wads (1/2"), cork (I think it was 1/8"), and overshot cards. I already have #F (0.22") and #1 (0.30") hard cast lead balls that I made years back. It was WW with a big dose of lino.
I cannot find recipes for these components, so I want to create my own. I have a bunch of Unique, and a bunch of International.
For plastic wads, with unique and a 3/4oz payload, 15gr gives around 9000psi and close to 1200fps. Am I safe in assuming that with 3/4oz, but using a gas seal and fiber, the pressure would still be safely below the pressure limit? Ie, if it's higher, it would still be safe?
Likewise for International, 12.5gr gives around 1200fps and 9600psi with plastic wads. If I work them up with 12.5gr, the fiber wad/gas seal substitution would presumably be below 12000psi?
How do people generally go about pressure testing? It's not cheap, so I think I would prefer to try and make a good guess to begin with, and hopefully verify the guess with data. Would it be smarter to push it a little bit, and try to figure out what's the maximum I could safely do, and then dial it back from there?
My goal is to make a low recoil round mostly for shooting paper and jugs. Maybe a 3/4oz close up coyote load from the 0.22" balls.
I just want to make sure I'd send the tester something that's safe on their end as well. It's concerning, from reading a lot of reloading data, how something like a wad change can add 2000psi. I had no idea it was that touchy! (which is why I have never deviated from a published recipe). Thanks for any ideas. This is my first go at it.