Is there a way to calculate velocity?

Cupcake · October 5th, 2008, 09:16 AM

I guess the first question is, why do a lot of reloading manuals give a velocity for a recipe, but fail to give barrel length and twist? Doesn't that make a pretty big difference?

In this case, I used 22.6 grains of H335, hornaday 68gr BTHP bullets, and a 16" AR15 with a 1:7 twist.

Is there some online calculator that would spit out a velocity, or does a guy have to pony up for a chronograph? (which is on the to do list).

SSDD · October 5th, 2008, 11:19 AM

In a word NO! You need to realize that every bbl is a rule unto itself. You need to chrono. Reloading is not about guessing! Chronographs are cheap enough, buy one or borrow one. NEVER GUESS!

Ram Rod · October 5th, 2008, 06:35 PM

Sure...a chrono would be a good idea. I'm trying to remember, but I think some of those variables can be plugged into the Lee Shooter program. I haven't been able to find mine since my last desktop crashed a few years ago, and don't have it installed on this one. You can do some searching here to see what's out there-
page8b

SSDD · October 12th, 2008, 02:58 AM

Be real and get a chrono! Use a 22LR rd as control, and actually chrono your loads.

October 5th, 2008, 09:16 AM	#1
Cupcake VIP Member Join Date: Mar 2007 Location: Michigan Posts: 2,664	Is there a way to calculate velocity? I guess the first question is, why do a lot of reloading manuals give a velocity for a recipe, but fail to give barrel length and twist? Doesn't that make a pretty big difference? In this case, I used 22.6 grains of H335, hornaday 68gr BTHP bullets, and a 16" AR15 with a 1:7 twist. Is there some online calculator that would spit out a velocity, or does a guy have to pony up for a chronograph? (which is on the to do list). __________________ Stupidity is not a crime...so you are free to go.

October 5th, 2008, 06:35 PM	#3
Ram Rod VIP Member Join Date: Dec 2007 Location: crawford county, arkansas Posts: 5,206	Sure...a chrono would be a good idea. I'm trying to remember, but I think some of those variables can be plugged into the Lee Shooter program. I haven't been able to find mine since my last desktop crashed a few years ago, and don't have it installed on this one. You can do some searching here to see what's out there- page8b __________________ RamRod-----sans remords

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October 5th, 2008, 11:19 AM	#2
SSDD New Member Join Date: Jan 2007 Location: MN Posts: 14	In a word NO! You need to realize that every bbl is a rule unto itself. You need to chrono. Reloading is not about guessing! Chronographs are cheap enough, buy one or borrow one. NEVER GUESS!

October 12th, 2008, 02:58 AM	#4
SSDD New Member Join Date: Jan 2007 Location: MN Posts: 14	Be real and get a chrono! Use a 22LR rd as control, and actually chrono your loads.