Deviation?

ArXane · Rookie Member Joined: Mar 17, 2009 Posts: 6

Does the software tell me somewhere what my standard deviation is?

Vince · Posted: Thu Jul 05, 2012 8:56 pm Post subject: Re: Deviation?

Can't say I've ever seen that function in there mate.

That is usually one of the functions of a chronograph. To get a standard deviation you would need to be able to enter the velocity of every round you fire and I don't believe you can do that with PB.

Cheers, Vince

DallanC · Site Admin Joined: Jan 18, 2005 Posts: 3572 Location: Utah

The old version used to calculate it. Its on my TODO list to bring it into version 2.0 ... I havent had any requests for it till now, but I can bump it up a bit and get it in... its not a big deal to add.

-DallanC

ArXane · Rookie Member Joined: Mar 17, 2009 Posts: 6

DallanC wrote:

The old version used to calculate it. Its on my TODO list to bring it into version 2.0 ... I havent had any requests for it till now, but I can bump it up a bit and get it in... its not a big deal to add.

-DallanC

That would be great. Thanks!

SyberShooter · Member Joined: Jul 23, 2010 Posts: 93 Location: Arizona

I usually calculate all that with my Excel reloading log (including MAD, ES, & 95% SD). Since the straight SD is technically only 65.4% of the expected variance range, I like to calculate the SD to the 95% level (2x SD) which I then add/subtract from the median velocity to arrive at an expected +- range that my reloads should fall within most of the time. Its a nice feature for some situations but in general the +/- velocity spreads can be eye opening (disappointing, alarming, scary etc) on otherwise good loads.

DallanC · Site Admin Joined: Jan 18, 2005 Posts: 3572 Location: Utah

Ok I have this in and working. I will run a few more tests to double check for bugs then I will push up a new version, probably later tonight.

-DallanC