PRB Ballistics

[SDSmlf]

Don't get me wrong, knowing an average velocity with all SD considered is a good thing while learning the distant and terminal ballistics of the rifle, but for me it's always been a result found "after" the accurate load is developed.

I have also usually found a good ‘SD’ with my most accurate loads, but have also found most loads with smallest SD were typically the most accurate. Kind of a chicken and egg thing. Small SD, accurate load. Accurate load, small SD. Doesn’t really matter how one gets there, does it?

 

[necchi]

Small SD, accurate load. Accurate load, small SD. Doesn’t really matter how one gets there, does it?

Your right.
But if your going to change patch, if your going to change powders, if your going to change bore condition,,
,All while testing nothing but velocity during those changes,, the SD is rendered mute as part of a "shotgun" approach to changing the variables searching for a consistent load.
But it is fun to document velocity data,, because it means the guy is at least shooting the thing,,
\
The OP has shared with us in this thread that he has changed, powder make, powder charge, ball size, patch thickness and shot to shot bore conditions with shots fired from two guns all while documenting for us the velocity of all 23 shots made in the last 11 months.
YOU, gather the data and figure the SD for the accurate load.
Get it?

 

[hanshi]

There is one important thing velocity testing (done properly) will do. Sometime back I was corresponding with Bill Knight (AKA "Mad Monk"). In discussing my results from a couple of chronograph sessions with a .40. Interestingly, my two favorite loads had the lowest sd and the lowest spread. The primary favorite load, 40 grns of 3F, had an sd of 5. The top load, a favorite also, had an sd of 17. The most consistent loads generally give the best accuracy and chronographing is the only to find out.

I don't chronograph loads in many calibers or in many rifles. So when I have a finely accurate load that has been reliable for a few years, I will often (but not always) chronograph that load. Of course it won't tell one everything one needs to know, but using a chronograph is a great help for most.

 

[Johnny Tremain]

My standard load for my 45 cal is 1630fps, so yours are hauling donkey.

 

[Santa Fe]

necchi
I’ve always been fascinated by ballistics this was never intended to be an exhaustive study. I’m just the curious sort and I thought some other Forum members might be in interested. Not everyone has access to a chronograph. As time permits I’ll do some testing

 

[necchi]

I’ve always been fascinated by ballistics,,
,I’m just the curious sort,,

I certainly get that part, . Me too.
Ballistics is a great study,, internal and external,, measured external velocity is part of it,,

 

[Okie Hog]

More round ball ballistics:

Plugin diameter of ball, velocity and sight in distance then hit Fire.

Rb ballistics (ctmuzzleloaders.com)