A chronograph is the finest tool I use in working up loads. I am able to compare my loads with factory (
read: safe-pressure in my gun) loads that have been shot from my particular rifle or handgun and work up to that velocity if I desire. Or at least compare them to what an average of reloading handbooks are getting from that load as far as velocity.
This is normally more important for someone working up hunting loads or handgun loads than for someone who only pursues accuracy on a range. It also is a real aid to those loading for autoloaders.
And unlike a standard tenet of "Conventional Reloading Wisdom," I have every once in a while seen accuracy come with loads that were overboard in pressure - a recent .223 TAC experiment that with the aid of the chronograph told me the "accuracy" load was too hot before most other pressure signs were readily apparent.
It will also tell you when your handloads are TOO SLOW! This can be very dangerous when loading light .38 Special
e.g., or other slower loads because you can stick one in the barrel and fire the next load into that bullet causing major damage!!
Knowing velocity also aids in inputting REAL data into any computer ballistic program, which is nice for getting a better handle on exterior ballistics.
I would agree with
Handloader Magazine writer John Barsness in his June 2008 article:
10 GOOD TOOLS
A chronograph does many things for the handloader. Obviously it indicates just how fast the bullet is going, but it also tells us how consistently the bullet leaves the muzzle. This may or may not have any bearing on accuracy, at least at "normal" ranges, and holes in the target are the ultimate measure of consistency. But when things are perking right, the chronograph is one more indicator of consistency.
More importantly, a chronograph is one of the great indicators of handload safety. Handloading lore is full of high-pressure "signs," such as hard bolt lifts, flattened primers, bolt-face marks on the case head etc. With a chronograph you shouldn't ignore those signs, but you can generally avoid them. A chronograph will tell you when you're approaching the practical maximum velocity for a certain bullet and powder combination. If you stop there, you'll normally avoid ruining any brass or stressing your fine firearm... |
I use the legendary Oehler 35P chronograph, but sadly this flagship of chronographs has been discontinued as Ken Oehler has retired and sold the company. They only make commercial stuff now.