Number of Rounds for Chrono?

[bigdawgbeav]

So I've had to switch powders and need to redevelop a 45acp load. This means a lengthy chrono session. Just wondering how many rounds to chrono for each load.

Just wondering what everyone thinks is a good number.

[Svickstc]

Not a whole ton of exp here with that, but i would venture you could see in 20 or so rounds...I know with my handloads when i test new batches its only 20 or so, but like i said im no pro...

Could get away with more or less id imagine, but for me reloading for target plinking i do i dont get caught up in that too much

[Guns N'at]

For me it's 5, maybe 10 at most, *IF* the machine catches the shots. You get a pretty good snapshot of your loads after 5 in my experience.

I wrote *IF*, because of my experience with Shooting Chrony. I had two, one bought in 1995 that got most of the shots, and I liked it pretty well. My second was a total POS after a couple years, was nearly all err's/no reads, read about 6% fast (yes, it was totally unfolded) and had a catch zone above the eyes about the size of a baseball. The company would not honor their warranty, and were snotty... Using a CE Pro Chrono Digital now, and love it. Nearly 100% reads in all lighting conditions, huge shooting area, light and speeds jive with other chronographs, and it's made in the USA to boot.

[NathanB]

I do 10 rounds per load. gives me enough data to make a decent estimation of what I need to do

[Brick]

I try to do 10 rounds for each charge weight and I vary charge weights by 0.2 grains to 0.5 grains depending on the range between starting and maximum.

[West Chester]

You are asking a statistical question. Obviously the larger the sample size up to a point the more accurate the average and standard calculations will be. You have to ask yourself what you wan the data to tell you. Are you shooting precision rifles at 1000yds , pistol plinking at 15yds or hunting rifle minute of lungs at 100yds