How many shots to gather speed

[John Klingenberg]

Honestly, I do one or two shots to get my basic come ups then true it on the range.

 

[Taylorbok]

and on how many different days?

I do 2 days. I go on one of the warmest days, then in the fall I go on a cold day +25*C and -10*C kind of thing but what ever your extremes are.
I only do 3 shots and then verify with drop at distance.

 

[8x68s]

any statistician will tell you "the more inputs, the better the outputs". in this sport we are limited... LOL

 

[QuietTexan]

Any time, any where, any shot that I possible can catch I do.

Any why not? All it will do is challenge your preconceptions with actual data points..... oh wait, that's why not. Introspection is hard And in the internet world where everyone shoots 0.100" 3ES/1SD 20-shot strings at 1,371 yards, it's just plain embarrassing to look at real numbers.

I think it was David Tubb who was using his Magnetospeed DURING Kof2M a few years go, pretty sure I saw it on someone's barrel on the series that up on YouTube, maybe it was an interview or something like that though.

 

[MagnumManiac]

Any time, any where, any shot that I possible can catch I do.

Any why not? All it will do is challenge your preconceptions with actual data points..... oh wait, that's why not. Introspection is hard And in the internet world where everyone shoots 0.100" 3ES/1SD 20-shot strings at 1,371 yards, it's just plain embarrassing to look at real numbers.

I think it was David Tubb who was using his Magnetospeed DURING Kof2M a few years go, pretty sure I saw it on someone's barrel on the series that up on YouTube, maybe it was an interview or something like that though.

Just watched the latest vid on Kof2M and every competitor had a Labradar in front of them. And all other necessary equipment.
It was very interesting to watch. 4 minutes.

Cheers.

 

[sierracharlie338]

I'm in the 10-15 group per "stage". 10-15 for fireforming load. 10-15 for shoulder bump load after powder charge is adjusted etc.

 

[camcraig]

At least 10, 20 is better and real statistical data starts at 30.
You don't have to do this in ONE SITTING, you can do it over a few shooting sessions.
If I test at 300 and 600 for average group size, I also use the chrony to get speed data on different days to see if anything changes.
If you just want quick reference points then 5-10 will suffice.

Cheers.

Yes I agree 100% I start at 10 minimum and I usually load a box of 20 and measure the base expansion with my micrometer to make sure that I am not to hot. Just my humble opinion.

 

[big johnson]

3 shots on brass that's been fired 2 times . If the SD is under 10 I go with it. If it's 10 or hlgher I'll shoot 3 more to see if the average changes.

 

[Tulsa Reiner]

Ok what everyone's magic number to get speed for the rifle?
I've always done between 5-10 depends on what I'm doing and components. What everyone else do. I lean towards 10 so my average speed is more consistent.

Cal Zandt has an interesting article in his Precision Shooting series, in which he goes into a detailed discussion of the value and weakness of the numbers (Standard Deviation and Extreme Spread), if you are interested in understanding the math. Bottom line, in answer of your question: he says chronographing 10 rounds is sufficient.

 

[Reelamin]

3 shots on brass that's been fired 2 times . If the SD is under 10 I go with it. If it's 10 or hlgher I'll shoot 3 more to see if the average changes.

Then what if it is over 10? Is it all about SD or a combo of max velocity and your SD requirements. Accuracy is separate to me.

 

[big johnson]

Under 10 sd is my personal goal and not some of my friends or maybe not alot of people on this site. usually sd over 10 I'm not happy with my groups and I change powder charge up or down .02 of a grain depending on where I am in the loading data chart Hope that makes sense. I used to chase max velocity ,but now that I'm older I don't care about speed any more and the tires on the race car last longer

 

[waveslayer]

Just watched the latest vid on Kof2M and every competitor had a Labradar in front of them. And all other necessary equipment.
It was very interesting to watch. 4 minutes.

Cheers.

that's because velocity changes almost every range session because of so many environmental factors, that's why they adjust on the fly for that exact Velocity readings. It isn't because they don't know it's because of all the environmental factors .

But OP. You can chase your tail on this, best is to shoot and chrono and every time you shoot use a chrono. Then you just use your best guess and ensure that your BC is trued, that's the most important part.