i just started reloading for my .308 about a month ago and i noticed that all the velocities are for a 22inch barrel. Since I have a 20in barrel i was wondering how much velocity i lose. Any help would be awesome
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new to reloading
- Thread starter millerlite
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Re: new to reloading
Heard a "rule of thumb" of 50 fps per inch. How accurate that is I don't know. If you have a friend with a chronograph you will get a better idea if you check velocity with that.
Heard a "rule of thumb" of 50 fps per inch. How accurate that is I don't know. If you have a friend with a chronograph you will get a better idea if you check velocity with that.
Re: new to reloading
I wouldn't worry about it then. Your velocity is dependent on a number of factors that will require that you measure it yourself. There is no blanket "50 fps per inch" rule, either.
Load for accuracy, not velocity. And once you find your accurate load, measure the velocity in order to calculate your dope, which you will verify practically.
I'm willing to bet that your rounds will shoot as far as you expect it to hit.
Don't worry about velocity right now. Your 20" will hit at 1k.
I wouldn't worry about it then. Your velocity is dependent on a number of factors that will require that you measure it yourself. There is no blanket "50 fps per inch" rule, either.
Load for accuracy, not velocity. And once you find your accurate load, measure the velocity in order to calculate your dope, which you will verify practically.
I'm willing to bet that your rounds will shoot as far as you expect it to hit.
Don't worry about velocity right now. Your 20" will hit at 1k.
Re: new to reloading
Go to loadammo.com/Topics/October5htm. There's a great explanation of where you heard this from. OTT, it showed that it was less than 50 fps for two inches of barrel length; but it has some variables that need to be explained. Formula for computing velocity loss and a CYA on why, "It don't mean nothin."
Go to loadammo.com/Topics/October5htm. There's a great explanation of where you heard this from. OTT, it showed that it was less than 50 fps for two inches of barrel length; but it has some variables that need to be explained. Formula for computing velocity loss and a CYA on why, "It don't mean nothin."
