I do like your process. I do find that one can do several things at the same time though. You can also be testing velocities and standard deviations while breaking in the barrel and fireforming. They may be a little less consistent, but they will still give usable data though maybe not as precise. With a hand lapped barrel especially, there is not really a lot of break in.
Why do you need to "fireform" brass that is already the same cartridge the gun is chambered for? Anyways after your first shot, you're going to resize it in a die that is going to resize it differently anyway...
It is all about reducing v9lume differences. When you fire forming the brass, you are expanding the brass to fit the chamber. Then, as you said, I will resize the brass and them load it again with the actual rounds or recipe that I intend to use. New brass is never as consistent as it should be due to the packing and shipping process. And it comes smaller than the chamber. When there is inconsistencies in volume and/or how much expansion is needed to fill the chamber when fired, that will create inconsistencies in the internal pressures. In return, you have larger Standard Deviation and larger Extreme Spread. It may not seem like much, but it is all the difference when it comes to group size on target. The name of the game is small groups and small SD and ES.
I didn’t see if you chamfered your cases prior to bullet seating. Did you or did I miss it? I’m asking because I have 100 Lapua cases I need to fire form for my 6.5 CM.
They shot just fine. I didn't really get stats on em. My 2 goals in this shoot was fire forming and barrel break in. I achieved both. Right now I am still in the development process with 153gr Hornady A-Tips and H1000 powder. Thanks for watching!
I do like your process. I do find that one can do several things at the same time though. You can also be testing velocities and standard deviations while breaking in the barrel and fireforming. They may be a little less consistent, but they will still give usable data though maybe not as precise. With a hand lapped barrel especially, there is not really a lot of break in.
I agree. I am happy with the results that I get.
Thanks for watching.
Did you misspell re: COAL? You started process desiring 2.95 and ended claiming 3.95 was perfect.
It was an oops. 2.95 would be the correct measurement. There is a 1 inch difference with the comparator.
Why do you need to "fireform" brass that is already the same cartridge the gun is chambered for? Anyways after your first shot, you're going to resize it in a die that is going to resize it differently anyway...
It is all about reducing v9lume differences. When you fire forming the brass, you are expanding the brass to fit the chamber. Then, as you said, I will resize the brass and them load it again with the actual rounds or recipe that I intend to use. New brass is never as consistent as it should be due to the packing and shipping process. And it comes smaller than the chamber. When there is inconsistencies in volume and/or how much expansion is needed to fill the chamber when fired, that will create inconsistencies in the internal pressures. In return, you have larger Standard Deviation and larger Extreme Spread.
It may not seem like much, but it is all the difference when it comes to group size on target. The name of the game is small groups and small SD and ES.
I didn’t see if you chamfered your cases prior to bullet seating. Did you or did I miss it? I’m asking because I have 100 Lapua cases I need to fire form for my 6.5 CM.
Yes. I did chamfer them
How did they shoot ?
They shot just fine. I didn't really get stats on em. My 2 goals in this shoot was fire forming and barrel break in. I achieved both. Right now I am still in the development process with 153gr Hornady A-Tips and H1000 powder.
Thanks for watching!
Primitive
In what regards?