Has anyone Chrongraphed Loads

[ohio ramrod]

I did a lot of chrony testing when I first bought my chrony. But I soon learned that grouping was more important to me than velocities. I do still use the chrony now and then to test powders for consistancy but I rely on groups to develope the best load for a new gun. :idunno: :idunno:

 

[Va.Manuf.06]

Good post ohio ramrod. Grouping is all that is important. The chronograph is an expensive waste of time.

 

[hanshi]

I've chronographed in fits and starts but seldom have done so in a "scientific" order. I did a fairly comprehensive bit of testing on my .40 with a 38" barrel. The results were interesting.
90grn lead ball, .020" ticking/Hoppes lube with NO wiping between shots.

30grns 3F = 1371 fps
35grns 3F = 1449 fps
40grns 3F = 1678 fps
60grns 3F = 1848 fps
65grns 3F = 1920 fps
Note the huge jump in vel from 35 to 40 grns.

With the .45 and its 36" barrel my figures were virtually identical to rb's until I got to 70grns of 3F which gave 1750 fps (rounded). .440 ball, ,020" patch/Hoppes lube, no wiping between shots.

Years ago I clocked a .490" ball through a 24" Traditions barrel at 1710 fps using 100grns 3F.

 

[hanshi]

Good post ohio ramrod. Grouping is all that is important. The chronograph is an expensive waste of time.

Maybe so, but it sure is fun to play around with. :thumbsup:

 

[jdkerstetter]

We all shoot through a crony set a few feet away from the muzzle but with a PRB that loses velocity quickly that is a poor test IMHO. What we need is velocity at various ranges- 50 yards, 75 yards, 100 yards. I once read that years ago a set of paper targets were set up- say 5 -10 yards apart- at the desired ranges (50 yards/100 yards/etc) and a level was used to set the two targets even. Then the bullet drop between the two sheets enabled one to estimate the velocity. NOW I'm probably wrong on some of the details- but that was sort of the nuts and bolts of it.

I would hope if this test were performed, and I don't doubt that it was, that it was performed before published data was available...and it has been available for some time.

Ballistics is a science and the formulas are out there as well as charts and computer calculators that will give you your velocity at any range.

If you know your muzzle velocity, Bullet weight, sectional density (or for round balls diameter), temperature and reference to sea level, you can find the velocity at any point very accurately. Drop needs the sight hieght and zero plugged in and drift needs cross wind.

Ballistic calculations have enabled artillerymen to fire over miles accurately for well over a century.

Setting up a chrony at varying distances or setting up targets on level would only confirm what ballisticians have known for a very, very long time.

Enjoy, J.D.

 

[George]

Grouping is all that is important. The chronograph is an expensive waste of time.

Except for the few fools of us who are interested in trajectories.

Spence

 

[roundball]

Grouping is all that is important. The chronograph is an expensive waste of time.

Except for the few fools of us who are interested in trajectories.
Spence

Of course it's not a waste of time...it's relevant information / factual data, the results of which shows what a ML and load is doing compared to published data, can clarify unknowns and misunderstandings, can often disprove old wives's tales, etc.
The original poster asked a simple basic question of the MLF members and a number of us have been offering assistance.

No, the real waste of time is evident in this thread...

 

[ApprenticeBuilder]

I once read that years ago a set of paper targets were set up- say 5 -10 yards apart- at the desired ranges (50 yards/100 yards/etc) and a level was used to set the two targets even. Then the bullet drop between the two sheets enabled one to estimate the velocity.

That series of tests came from the book titled "The Bullets Flight From Powder To Target" written by Dr. F. W. Mann, he was doing alot of work with Harry Pope and his barrels.

The book was about the ballistics of small arms and the causes of accuracy loss at the target, its actually a great book for those interested in true accuracy. The book was written in 1909 and was very cutting edge for the time.

The section you describe had to do with deformed projectiles and also shooting within 1/4" or less of a fixed object and how this affects the flight path of the projectile.

One very interesting tid bit was the effect of frontal deformation and how its meaningless, but the base is another story.

When I was mucking around with the modern stuff I read this book.

 

[Dean2]

Thanks for the quality info RB. Clearly tells me a lot of what I have been reading is not correct. The lower charges might be fine for target work but the heavier charges is definitely what you want for larger game.

Pretty clear that more powder equals more speed, and it is pretty linear. My .32 groups as well with 15, 20, 25, 30 or 35 grains of powder, all that changes is POI. I settled on the fairly light load of 25 grains of Goex 3F, .310 Hornady ball and .018 patch as it groups well and since it is a small game, and paper punching rifle, the light load has no kick and gets lots of shots per pound of powder.

If I was shooting a .45 or larger for big game, I would definitely be using the heavier loads for flatter trajectory and better energy on target. Thanks again.

 

[nkbj]

Used a chronograph to great extent when designing cartridges in the '80's... and I kinda miss it. Could get a multi-function wonder machine now for what a klunky Ohler black box and sky screens cost back then.

 

[damron]

How many shots in each load/charge change for the velocity data?

George

 

[roundball]

How many shots in each load/charge change for the velocity data?
George

5 shot strings
Averaged the 5 readings for each powder charge
Rounded off the average to the nearest 5 FPS

 

[ebiggs1]

paulvallandigham
Mr. Biggs and his fans always FAIL to mention that the Davenport Formula

jerry huddleston
You left out the phraze, [ for maximum efficiency]

ebiggs
I didn't make mention to the Davenport Formula!?

Did I? :hmm:

 

[roundball]

Did I? :hmm:

Of course you didn't...claims like that is the game played when someone is trying to save face.
This is yet another thread that's been hijacked with irrelevance.

 

[jdkerstetter]

This is yet another thread that's been hijacked with irrelevance.

TROLLS!!!! :rotf: :rotf: :rotf:

 

[crockett]

Yeah- that's why no one seems to put a crony out at 50 yards or 100 yards- a stray shot could trash the device. Terminal ballistics however seems to be what is really important, not what is happening at the muzzle.

 

[roundball]

Yeah- that's why no one seems to put a crony out at 50 yards or 100 yards- a stray shot could trash the device. Terminal ballistics however seems to be what is really important, not what is happening at the muzzle.

You've got me thinking...I bet in this day and age more sophisticated units are or could be available, or made...may not be enough of a market for them though.

Imagine a remote unit with larger screens including a recording unit with wireless transmitting back to the main unit on the bench...or a removable storage card like those in digital cameras, etc.
:hmm:
Biggest question would be making or buying a heavy steel protector...do you spend a fortune to protect a set of $25 screens or not

 

[jdkerstetter]

You've got me thinking...I bet in this day and age more sophisticated units are or could be available, or made...may not be enough of a market for them though.

Really? There are units today that have PC interface with ballistics calculators that will figure velocity and drop based at any distance on standard screen placement.

The only thing you achieve by placing screens downrange is confirm what the engineers have already worked you after years of R&D.

How do those snipers make those 600-1000+ yard shots without shooting through chrony screens at all those distances to confirm their velocities? Ballistics calculations based on know values.

The work has been done for us already.

Enjoy, J.D.

 

[George]

A ballistics software program coupled witha good chronograph makes it unnecessary to shoot over distant screens. Using muzzle velocity and a little other data, true drop, bullet path, decreasing velocity and energy over distance and time of travel to target are at your fingertips. Tell it the distance you want the gun sighted for and it will give you the near and far zero, point blank range and mid-range trajectory. Change the elevation, temperature and pressure and it will compensate and show you the correction. Change incline angle, crank in some wind of any angle and speed, and the effect is available. All that from muzzle velocity at minimum chronograph range. And no walking.

Spence

 

[roundball]

I agree completely...but still, ya gotta at least find this possibility interesting.

"...Imagine a remote unit with larger screens including a recording unit with wireless transmitting back to the main unit on the bench...or a removable storage card like those in digital cameras, etc..."