Chronograph Data!

[DirtyHarold]

I finally bought a chronograph and took it out to the range to collect some data. I decided to try a bunch of different 357s and I was lucky enough to get a hold of the following - SP101 3", a GP100 Match Champion, a Colt Python 6", and a Glock 32 357 SIG. I am really excited about this! I am really happy with the data. It was an expensive range trip for us. Some of the results were surprising IMO where some rounds I feel overperformed and some underperformed. Let me know what you think.

Chrono was about 10' from the muzzle.
Temp: 37F
Humidity: 61%

A photo of the chart with all the data is in the attachment.

 

[DirtyHarold]

Here is a target. It was the first time out with the Python so we shot it a little more than the others. Almost all of this was done with wrists rested trying to go for accuracy. Sorry I don't recall which ammo was used for which groups.
Range 10 yards, little to no wind. Not the greatest shooters here but still not bad.

The Python shot about as expected (very good). Some of the loads shot great, some just ok.

The real surprise were the Rugers, the little SP101 shot a really tight group and the GP100 put 4 of 6 rounds in 5/8 inch!!!

Did not take any shots with the Glock, though from past experience, with the right ammo is surgical.

Didn't shoot a ton of accuracy shooting because of how much ammo was already being blown through on the chrono testing.

 

[rock185]

I've always been ballistically curious, and have been using chronographs for about 40 years now. Most shooters are content with whatever velocity figures the factory publishes, but actual results in real world guns can sometimes vary significantly. And with handloads, published reloading manual results are sometimes a lot different than what one's particular gun produces. The article, "Why Ballisticians get gray", in Speer manuals years ago, has a good discussion of this.

Enjoy that new chronograph.

 

[DirtyHarold]

I've always been ballistically curious, and have been using chronographs for about 40 years now. Most shooters are content with whatever velocity figures the factory publishes, but actual results in real world guns can sometimes vary significantly. And with handloads, published reloading manual results are sometimes a lot different than what one's particular gun produces. The article, "Why Ballisticians get gray", in Speer manuals years ago, has a good discussion of this.



Enjoy that new chronograph.

I’m already having so much fun. I’m really surprised at the data, for example I can’t believe how slow the CorBon 357 SIG ammo is. Way below advertised velocity. And for the Hornady ammo they say they use an 8” test barrel, yet my 6” is basically at that velocity.


Sent from my iPhone using Tapatalk

 

[Ricklin]

Pretty Impressive

I'm rather impressed that the factory velocity data is pretty darn good overall.

Other than a couple exceptions, the factory data is quite accurate. Esp. when we consider the variety of guns.

 

[44 AMP]

I have seen 100fps difference in three guns all with the same (nominal) barrel length) shooting the same ammo.

I have seen shorter barrel guns shoot faster than longer barrel ones, and while not common, it DOES happen.

What the factory gives us for speed is what they got, from their gun (or test barrel) and should be considered a guideline, NOT an absolute. You MAY get what they got with what you have. You may get less. You may even get more.

These things are governed by the factors specific to your individual gun and ammo.

Generally speaking, a handful of fps, while measureable, is not significant, particularly at usual handgun speeds.

 

[RC20]

Back when I was under 50, accuracy would have been important (I could shoot 1.5 inch groups at 25 yards with the Model 57)

Now I am happy to get a decent pattern at 15 yards.

Can't see the iron sights that good, free hand I wobble but I can keep it inside of 4 inches mostly.

sucks getting old but have found no solutions for that.

 

[Shadow9mm]

Chronographs are AMAZING tools. Every gun is a different animal, and barrel length makes a difference. I love mine because it actually lets me see what is happening in MY guns, and in my case, how my hand loads are performing. Most of the ES and ES all looked good for handguns IMHO, some were fantastic, a few were not great.

 

[jrothWA]

The closer the ED is the better and the lower the Sd date is great.

What actually counts tho is the group on paper.

As a high power shooter the ES in the low twenties (20) to tens [10] will minimize the long yardage shot from dropping out to a lower scoring ring on the target.

 

[DirtyHarold]

Question for those who have experience with chrono data, I got some pretty high ES numbers out of these guns up above 80. From your experience, is this typically ammo related or gun related?

 

[44 AMP]

From your experience, is this typically ammo related or gun related?

It can also be chronograph related. Repeat the test on a different day, with everything the same except the time of day and angle of the light. You might get different results.

IF your chrono results are consistent, under different conditions, then velocity spread is most likely ammo related.

A slight change in the ammo, up, down, (or sideways, ) CAN change the consistency and the chrono reading you get.

Do remember to only change ONE thing, then test. Changing more than one factor leaves you wondering which change did what....

I got some pretty high ES numbers out of these guns up above 80.

Just to be clear, you're talking about velocity spread in the ammo fired in ONE gun, right? Not comparing the velocity differences between several guns firing the same ammo?? Because those are two different matters.


Good Luck

 

[stinkeypete]

most chronographs work on measuring the time between dips in light from the shadow of the bullet, across two electric eyes.

The distance between the electronic eye sensors is fixed, so the variation due to the chronograph can only be due to changes in the timer circuit inside the chrony.

So long as the machine is warmed up and the temperature is stable, timers are very consistent.

Thanks for the considerable work in taking this data and showing us! My conclusion: .357 sig really is no joke. Also... I like hand loading even more now.