We all know that scant amounts of fast powders and small amount of medium powders are used for target loads but what about the standard loads as well as magnum type loads.
I have been doing a lot of test with 6" and snub nose loads the past few months and am putting all the data in my log book and will go over it when the weather is too bad to go outside and test loads,which will be soon, I just need one more test.
I have noticed that different primers and crimp pressures do make a differeence on velositys and patter accuracy but I also noticed that with the best primers and crimps for a load, the amount of a powder also has an effect on velositys and target accuracy.
When loading rifle ammo many of the loads call for at least 68% of case volume to make sure the primer will be covered with powder but you never hear or read about this with pistol reloading to my knowledge and only Nosler has a minimum and maximum Density % of powders in their data, that I can find.

Testing one load in my 686 6" with a 110 jhp bullet........ only 9.5grs of a powder with a f100 primer gave higher velositys than did 11.0 grains of the same powder with the same components and crimp.

Does case volume with standard or +P loads mean anything or am I making a mountain out of a mole hill?

If you'd care to share your data from your log book maybe it will enlighten some of us to make an opinion.

I haven't explored the topic like you have but I think there is a general acknowledgement that with certain loads, if you tip your gun up before each shot you will obtain different results than if you tip it down, so something to do with powder position and by inference, % of case volume, seems to be in play there. So I too think there is a correlation.

How do you gauge the amount of crimp your putting on from load to load, bullet to bullet, session to session?

I'm not sure I understand the question either. Even though most powders have a wide range of uses, most of them have certain areas where they are better than others. Even with powders that are close in burning rate it doesn't mean they are close to being equally good. Some are more sensitive to position and loading density than others and depending on case volume some of their burning rates will change. When working up loads I always research the powders that are listed in the various load data to make sure it's a "better" choice for the task at hand. The difference in velocity in the load you mentioned may be due to several things. The increased heat and pressure from the higher load maybe changing the overall burning characteristics or it may be that with the higher load density the force from the primer may be dislodging the bullet before the powder fully ignites creating a larger combustion chamber. The first would creat an increase in pressure while the second would cause a decrease.

Crimping question;
All my brass is set into units as per how many times they have been fired and by make.They are then sized,deprimed and expanded for the next reloading.

My die has marks on it per a light crimp,medium crimp and heavy,which I use for lead bullets in +P loads.
The brass should measure 1.15 to 1.155 if shorter it is placed in a "Odd" box, and the brass is then sorted to size and marked so the crimp will fall in the correct area. Many of my jacketed loads are set first with the correct OAL then crimped in the fourth stage,since some factory canelures are not all placed in the same spot on the bullets.

2" snub nose Data, win. 110 sjhp,cci500,med. crimp.
Unique 5.8gr 793-960fps ES 167
Unique 6.4gr 905-960fps ES 55

Suter's 158 Lswc cci500 Hvy. crimp.
Unique 5.0gr 794-863 ES 69
Unique 5.2gr 773-896 ES 123

6" 686 Magnum win 110 sjhp,f100, med. crimp. 38 brass.
SR4756 6.2gr 817-961 ES 144
SR4756 6.6gr 875-1135 ES 260
SR4756 7.5gr 970-1056 ES 86

As you can see some of the lower powder loads are the same or higher in velosity than the loads with MORE powder. I do not do the muzzle down or up, thing.......and just wounder why this happens in light and heavy loads.

I've got to go along with 125JHP on this one.
Without seeing you do your chrono measurements, the most likely answer is that you are seeing variations caused by your chrono technique, not your loading.
The fact that you don't systematically position the powder suggests you are producing bogus data that have nothing to do with lower amounts of the same powder giving lower velocity--they don't unless you introduce another variable.
I do a lot of chrono work at matches, and I often see folks that don't know proper chrono technique. Like anything else, there is a learning curve, and having an expert check your technique and do mentoring helps tremendously.

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Science plus Art

Are the 158 gr lead bullets being shot out of the same 2" barreled gun? If not none of this data can ever be compared especially if primers and powder also change. Only one variable can be changed at a time if you want comparisons other wise its all speculation. If it is the same barrel lead bullets also tend to be faster or require less powder to reach the same velocities as jacketed bullets. However since the 2 loads are 158 & 110 gr this is a bit weird. How far was the chrono?

The rifle range has a seam in the cement at 9 feet in front of the tables and the chrony is set up at the same distance,the same way,every trip. Their is tape on the four legs to mark the line where the sights should aline for the bullet to pass in the same spot each time for the load, in the center of the chrony both vertical and horizontally.

The revolvers are shot off sand bags with with no contact with the barrels...........................
and yes the 110jhp and 158L were both out of the snub nose.

I know that you will get two differen readings for a down vs up barrel before shooting...........why can't I just get reading from a sand bag which will be more to the method of firing off hand at a "Target" or SD case ?

You may be missing the point of tipping the gun up or down before
firing over the chronograph. To see the effect of variations of your loads
on velocity, powder charge, crimp or whatever you must be consistant
in your chronographing technique period. Consistancy in powder
positioning is a must or your readings will reflect your technique, not
load variations. There's nothing wrong with firing from sandbag rest to
simulate offhand shooting but the reason for chronographing is to
check your handloads and so your sandbag readings will be largely
irrelevant.

My brain is begining to itch. It's too early in the morning for this. I'm a load and shoot kind of guy, own a chronograph, and simple is better.

At matches, it is align the sights and squeeze the trigger. For me that is real world shooting so I use real world results. But thank you for an interesting read. Now I need more coffee.

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S&WHF 366

Those are some pretty wide readings. It could be your chronograph technique or it may be due to your powder dispensing/measuring tools and techniques.

I don't usually bother with chrongraphing handgun loads anymore, especially for target and self defense loads. I have enough gray hair the way it is.

Some of the ES you are getting is usually a detriment to accuracy. Are these all bulky powders like Unique is? You don't mention how you throw your powders. If you are just throwing via the powder measure you may be getting much more variance that you think. Bulky powder doesn't meter well, that's why I switched to mostly all ball powders long ago. I use an RCBS powder measure, and with 231 it meters +/- a half a tenth of a grain. For rifle powders, usually stick type, like Varget, I hand weigh every load. My Prairie Dog rifles all shoot under a 1/2" at 100 yds.

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H Richard
SWCA1967 SWHF244

Thanks for your ideas...........

Each load is weighed on a scale before the powder is placed into the case.

There might be a better way to get better readings but I don't think a BG is going to wait for me when I ask him to stop, while I position my powder in the case.

Guess I will have to use the old "Redneck" way.

I wouldn't worry about powder placement in a BG situation but when your testing for numbers it might make a slight difference. Otherwise all that matters is placement, penetration and expansion. As I understand it, I don't think it makes a lot of difference if the case has a good amount of powder in there, mostly filling the case, it does seem to be of interest when using small amounts of fast powder that would lay below the flash hole allowing the flame to go over it.

Ed, your problem isn't with powder positioning, it looks more like either the chrony is giving some erratic readings or your charge weights aren't reading right.

Is your scale digital and do you have any check weights? And have you ever shot any factory ammo through the chrony? And if so, was it consistant?

Jellybean;

It could be my chepo Beta chrony..............but it at least gives me ball park info where I can at least figure out the energys of my loads +/- .

I have shot Federal 158lrn factory in my snub nose and it's 3.5grs puts out 647fps and I can match it with 4.0grs of trailBoss.

I do have a target 158L at ES 29fps, a FBI 158gr Speer at ES40, a 148hbwc at ES 28 and a 135 GDot +P at ES 9 fps.......all at or near poa.
I just tested a target load 158 LRN today at 10 feet with the snub nose and did not look at the chrony........not important, since all 5 were in a cluster at the edge of a 1.25" orange dot, that measered .54" over all.
Just funny that you get lots of loads in the 40 to 80 ES and then for no reason there is a 120 or a 167 reading on the screen.

Done testing the snub nose, time to put it away and grab the 12Ga and go out and get some ducks and geese while there is still time.

Good shooting

Your beta chrony is probably working just fine, I wouldn't worry about it's output if it is fairly consistent from test to test with the same ammo. I don't have one but I have heard countless good reports on them and I doubt they are any less accurate than other competing models without adding a 0 or two to the end of the price.

FWIW I have a pretty good database of loads I have tested and better quality factory ammo often has an ES of 25-30 in semi-autos and 40-50 in revolvers. This is just eyeballing the numbers in my spreadsheets from several pistols tested in different calibers. Some of the OEM stuff has shown ES up to 150fps! Surprisingly, Blazer has shown ES numbers in the teens more often than any other OEM I have tried.

ES isn't that good of a consistency indicator. You probably should be looking at Standard Deviation as a better measure of how consistent your velocities are performing and maybe even compute it out to the 95% level with Excel to see what hi/lo range you should expect out of any given load.

I sort my brass by head stamps and hand trickle each of my test loads and try to be as consistent as possible, but even then I will get a flyer or an extreme velocity variant more frequently than I would expect (or like). I can't account for them by anything I'm doing during the load process, so I figure it must be a combination of component variances or some other hocus pocus. I just shoot until I find a combination I like that is repeatable. It's the shooting that is the fun part.

Ed, with the closer ESs on the other loads it looks like your powder handling tools and techniques are capable enough. It is possible you are getting some wild readings on the Beta Chrony. I have an older Chrony model that I used to use a lot, until I was working on an experimental idea and shot one of my light diffusers in half. Now in bright sunlight it can't be depended on to give an accurate reading so I have to find some shade or wait for a cloud to move in.

But in the meantime, I learned that a narrow ES doesn't really matter for SD ammo or even for shooting targets at a set distance.

With your screen name I gather you are in Nevada (can't fool me)

I went through two Chrony brand units here in SUNNY Florida. They did not work worth a damn. Very inconsistent, sometimes no readings, sometimes gibberish. Tried everything, shade , different screens , card board etc etc. The angle of the Sun just killed it. I returned them.

Bought a Competition Electronics Pro Chrono.

Problem solved!

Just a thought

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Still Running Against the Wind

I don'tknow about you guys but.................

Those plastic roof set ups in day light sort of suck..........

At the rifle range the unit is in the shade of the metal roof ( not a good thing ) with the sky over head. Very seldom do I get real bad readings, maybe a error if I miss the C/L of the unit or too high (never low!)with a bullet. Just put the four metal rods in the unit that has a bright orange ribbon scotch tapped to them, half way up, that aids in my aiming spot.

Seems that about 6" over the unit works best for a revolver, I
use at least 10" with a shotgun !!

There is always going to be variations in vel from one shot ot the next. Yes, case volume has an affect on pressures & vel. Yes, pressures have diff affects on diff powders. Medium burners like Unique, want higher pressures for a more uniform combusiton. The reason powder volume isn't as critical in handgun laods is the powder is quite fast.
COnsider the fastest rilfe powder is the slowest pistol powder, position of the powder isn't as critical for good cumbustion.
As to good chrono readings, first you need a good chrono, The Chrony line are not it, not at any price level. They all use the same poor screens. Then you must be far enough away to not have blast or ejecta trip the screens. Fot me, 10ft is min for handgun, 15ft for rifles.

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NRA Cert. Inst. IDPA CSO