4grs and a 158 RNFP from Missouri bullets, lubed

66 4"

731
688
719
705
749
734

Avg 721

66 6"

773
746
739
737
778
780

759 avg

What is the question?

First, 6 round samples are not statistically significant. You really nee to fire at least 20 round samples to be even reasonably confident in the data obtained.

Second, velocity results from different guns mean nothing when compared with each other. I have .38 Spl and .357 Magnum revolvers ranging from 2" to 6 1/2". Often my 4" guns will show higher velocity with the same load than any of my 6 and 6 1/2" guns! It will take chronographing hundreds of rounds in each gun to make a significant observation of the relative velocity potential of each of your revolvers.

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Gunsmithing since 1961

Those appear to be light .38 loads.....If that is what you're striving for great!

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S&W Accumulator

Not much to comment on.

Did you have fun?

How about building a story behind your data

Or pictures of the guns and targets, heck or even puppies
Everyone likes puppy pictures

Or you can list all the details, so everyone can tell you what you did wrong

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I'd like to agree with you BUT

It's an answer, not a question. Who cares if it's not statistically significant? It shows real world results, not Hodgdon's overly optimistic velocities.
Thanks OP

Simply following up on a previous post about Universal loads. Very mild loads obviously.

But which thread or post?

Did someone say PUPPIES??

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Still Running Against the Wind

I'll contribute a puppy and a kitten to the thread.

"It shows real world results, not Hodgdon's overly optimistic velocities."

Especially with revolvers, you can't believe the MV information provided in anyone's reloading data. Not the bullet manufacturers, the powder manufacturers, the reloading equipment manufacturers, no one.

Which is why I bothered to measure them. I'll try 4.5 grs next. I like mild stuff in these K frame's.

Dogs can be very funny, even when they're not trying...

Attached Images

f6558e0753dog-baby-photos.jpg (23.8 KB, 109 views)

I for one greatly enjoy reading about the chrono results other are getting in their guns. So keep those results coming everyone.

I found that if you run out of Alliant Unique powder...
Universal can take over the job in either 12 Ga. or my 38 or 357 loads.

Seems a little cleaner and meters better and one thing I liked.....

it was a great powder for X-lite target loads with a 125 grain bullet
in my little J frame snub nose, at around 600fps.

I'll add a puppy and a kitty

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I'd like to agree with you BUT

With 38 cases I got 857 with a medium load of Universal.

In a 357 case you make that 158gr lead bullet get up to 1315fps out of a 6" barrel....
or pull the reins in to a mild 1156fps.

Looks like good data to me. I shoot 38 level loads in my .357 with a 6" barrel. Thanks, Stan

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"He was kinda funny lookin'"

That should be interesting; the .38 special load on my canister of Universal is 5.2 gr. for 1032 fps, iirc, which shoots really nicely in 357 brass...that is Hodgdon's "overly optimistic velocity". I do believe Mother Hodgdon uses some outlandishly long barrels to produce their velocity data. I think we all wish they would shorten them somewhat.

In the older Lyman manuals, they said they used a vented 4" barrel for its .38 and 357 Magnum data, but in my latest manual, it just says a 4" barrel. Oh, well...progress. (?)

For my purposes 3-6 shots are fine. I just started with some tests that go beyond just checking the velocities and will probably do a little more analysis.

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"He was kinda funny lookin'"

I'm about to start running more 357's with Universal through the chrono along with some reduced 243 and 257 Roberts loads for the kids. The rifle loads won't be with Universal.

By the way, those light 357 loads are a blast in my Marlin 1894, fun gun.

My chronograph does all the stats calculations for me (average, ES, SD), but only for strings of up to 10 shots.

The results mean exactly what they say. Sure, different guns/barrels will give different velocity results with exactly the same load (not necessarily always higher fps with longer barrel, lower fps with shorter barrel) . That's why it's actually useful to chronograph the same load (if you're planning to load and shoot lots of it) in multiple guns, so you know what to expect with that load from each gun. OTOH, if he's getting 700-800fps from them in one .357 revolver, it's a reasonably safe bet that they're safe to shoot in any [otherwise safe to shoot] .357 revolver.

I shoot a lot of different bullets with 5gr Universal from 130gr coated lead to 158 coated lead and some Berrys Target HP. Have really started liking this powder. Meters well in my Dillon 650 and shoots very clean. The loads I've run through my chronograph show it is very consistent. Got several thousand of various weights loaded and ready.

Your loads are near Hodgdon load data they use a 7 1/2'' barrel. So with that said enjoy playing with your chrony. Ladder up your loads and shoot targets as well.

Statistics is mainly a matter of confidence you can have in the results. If you fire five shots and get an average MV and then ten shots, you can have considerably more confidence in the average MV from firing ten shots being correct, all other factors being the same. Of course, there is a limit at which the incremental increase in confidence is small vs. the time and effort it takes to get it. Mathematically, the standard deviation of the mean (which somewhat represents confidence in the mean) is the standard deviation of the population (shots fired) divided by the square root of the population number (5, 10, or whatever). Let's say you fire 16 shots and get a mean MV of 1200 ft/sec with a SD of 40. The SD of the mean would be 40/(sq. root of 16) = 40/4 = 10. You could then be highly confident the true mean MV would be in the range of 1200 +/- (3x10), or 1170 to 1230.

My chronograph does not record. I write everything down and later use Microsoft Excel to calculate the MV means and standard deviations. I generally fire no fewer than ten shots nor more than 15, as I think that is enough for practical purposes. In an industrial ballistics lab, they might fire 20 or even 50.

If I got a standard deviation of 40 on the first cylinder there wouldnt be a second.
No reason to shoot that many rounds in ladder work. Single cylinder can tell you what u need to know. You can watch the velocity and SD change and figure out if the combination is working or not before wasting alot of components.
Its only then when I have things dialed in would I load 50 rounds or so and sand bag for groups and confirm velocity.

I agree.

Small shot counts may be problematic (in terms of fundamental precision) from a long-term statistical standpoint, but they're generally fine for our purposes and context.

When running a pressure (ladder) series I'm looking for two things... signs of pressure and accuracy. More broadly, I'm looking for patterns.

I'm dismissive of unicorns... a single really pretty group or a lone very lovely SD number in the midst of garbage.

But when the groups and the SD tighten up in lockstep you're almost always on to something. When you head home with a smile in your heart from what you saw and a pretty good idea of what your next loads at the bench will be - tossing out the bad ones and spending more time with those that show promise - you're on your way, maybe, to one of those great loads that pass the test of time.

You'll end up eventually with the shot counts necessary to make the statisticians happy, but it might take a few trips.

Yeh pretty much, I am usually loading for a game with rules on power factor (weight times velocity) So will usually aim for that level plus 5. Once I have that average down, and single digit SD's, I'll shoot some more of that one loading to iron things out.
Although I have learned to not try to reinvent the wheel. For any particular use there have been plenty of experimentation doone and You will find a very small set of components being used over and over by large percentage of users. Usually all thats required is a tweak of a 1/10th grain or two and maybe an OAL adjustment.

Well, I'm trying to keep things simple. I like one load for all 5 of my revolvers and the marlin 1894 in 357. Set up the Dillon and run em all the same. We shoot steel. Even the ladies like these loads. The 27-2 hardly moves, the 586 some. Fun for all

And there is alot to be said for that. when I find a load that Mrs Dumpstick enjoys shooting, you can lay odds that there will be several hundred available at any given time.