Coal adjustment

[sigtactical]

well,i have a question i'm still not able to fully understand , it still half a mystery to me, and i know many of you guys are deeply involved into reloading ,so i told myself maybe i could find an answer explaining it all.

i'm presently reloading some 9mm rounds 147gr with vv340.


my vihtavuori reloading data book stipulate an COAL of 1.142, but i want a 1.100 max COAL for my CZ shadow,so my question is:

how far we can play with the recommended COAL , and how it affect the whole round VS the pistol.

should i load a lower charge since i reduced the headspace of the cartridge , shortening the COAL lenght, or can i still load to max charge even if i've reduced the headspace in shortening the COAL??

...and what about load density if i reduce the gap between the powder and the bottom of the bullit?? what's the minimum space allowed between powder and bullit base?? is that bad if the load is mildly compressed??

all i realy know, is that a 9mm max COAL is 1.169,then, when i look at some reloading data across the different books, i notice it seem suggestive a lot.....HOW IT WORK??

thanks for sharing your knowledge .

 

[sigtactical]

eeeu,anyone know,or am i at the wrong place??

 

[jethunter]

well,i have a question i'm still not able to fully understand , it still half a mystery to me, and i know many of you guys are deeply involved into reloading ,so i told myself maybe i could find an answer explaining it all.

i'm presently reloading some 9mm rounds 147gr with vv340.


my vihtavuori reloading data book stipulate an COAL of 1.142, but i want a 1.100 max COAL for my CZ shadow,so my question is:

how far we can play with the recommended COAL , and how it affect the whole round VS the pistol. should i load a lower charge since i reduced the headspace of the cartridge , shortening the COAL lenght, or can i still load to max charge even if i've reduced the headspace in shortening the COAL?? You can make adjustments to cartridge length, but good to to decrease powder charge 5% and work back up to the max.

...and what about load density if i reduce the gap between the powder and the bottom of the bullit?? what's the minimum space allowed between powder and bullit base?? is that bad if the load is mildly compressed?? No. lightly compressed load is good

all i realy know, is that a 9mm max COAL is 1.169,then, when i look at some reloading data across the different books, i notice it seem suggestive a lot.....HOW IT WORK?? You can make the adjustments to fit your pistol, just remember that shortening COAL can increase pressure, so decrease the load and work up again whenever you make a change to OAL.

thanks for sharing your knowledge

 

[iceman2]

You are not changing headspace on a 9mm by having a shorter coal. You headspace on the case mouth , not the bullet. Shorter round means less internal volume means decrease load and work up in my opinion. Just my opinion and worth what you paid for it.

 

[sigtactical]

You are not changing headspace on a 9mm by having a shorter coal. You headspace on the case mouth , not the bullet. Shorter round means less internal volume means decrease load and work up in my opinion. Just my opinion and worth what you paid for it.

well, if i follow well, is that mean that if a 1.142 coal is mentionned for a 3.8 gr charge(minimum load), shortening the oal to 1.100 - 5% load would mean reducing the load to around 3.6 grs???

 

[jethunter]

well, if i follow well, is that mean that if a 1.142 coal is mentionned for a 3.8 gr charge(minimum load), shortening the oal to 1.100 - 5% load would mean reducing the load to around 3.6 grs???

yes. Then if that load works ok, increase/test load in .2 grain steps until you get where you want to be.