Load testing data

P

physikal

New member
When you are working up a load and you go to the range to test it, what kind of information do you log/track?

For example, I'm a noob so I typically only gather velocity of each shot. I usually work up 10 rounds of a new load and log each shot's velocity then track the average difference.


So my logs look something like:

Rifle - Barrel Length - Load Data (bullet & weight, brass, primer, powder & weight)

Shot 1 - 2700fps
Shot 2 - 2790fps, etc.


What additional information is important that you track?
 
I generally write down environment as well, that way I know what type of weather I was testing in. Temp, Wind, Humidity, Density Altitude, time of day, sunny, cloudy, wind direction, etc.
 
I used to chronograph test all of my loads, ten shots of each powder charge, noting average velocity, extreme spread, standard deviation and high/low. For a while I was really into the chronograph and I did learn a lot from it. I found that shot-to-shot consistency isn't always a predictor of best accuracy though. Nowadays I just shoot for group, ten rounds of each charge fired into a single group. Best ten shot group wins and is what I settle on for that bullet/powder combination. Shots on target is what really counts.

Ten shot groups is what I use for pistol. For rifle I only shoot five, whether over the chrono or on paper. If five shots out of a rifle doesn't look promising five more of the same load probably won't improve things. Time to stop wasting components and move on.

I'm not advising you to give up on the chrono by any means. You will learn a lot from it, especially as a newbie. Always verify your loads on paper though. I've had loads that had good SDs and were at my desired velocity but couldn't group minute of pie plate.
 
I write up any shooting like a lab report.
I write up any hunting like a trip report.

"Who would have thought reading and writing would pay off?" -Homer Simpson
 
mmb713 said:
For a while I was really into the chronograph and I did learn a lot from it. I found that shot-to-shot consistency isn't always a predictor of best accuracy though.
Click to expand...


Depends on distance when it comes to rifle.

At 100yd, it doesn't matter all that much.

At 600+ yards, it matters a lot.
 
I write down each velocity, Standard Deviation, Average, Extreme Spred, Group Size. I then calculate what I need from each load to make either major or minor power factor for USPSA or ICORE matches and calculate what I need.

Once I know what will make the factor I need I test accuracy again and then I'm good to go.
 
Here is my load data sheet . I covers pretty much all I need . In the case of hand gun loads it has much more then needed .

Feel free to use it if you'd like . I make copy's with the data on the front and back giving me 4 data sections . I then shoot at a same sized paper with 4 targets on it . The data sheet and target are then stored together in a 3 ring binder for future reference

http://thefiringline.com/forums/attachment.php?attachmentid=100403&d=1446367658
 
I've simplified my testing, I use labels with sticky backing, the load, the rifle, and brass type are written down on this label and stuck on the plastic bag that the 5 rnd test is in. The label is stuck on the target just below the group, and the brass is put back into its own bag until it can be diagnosed back at the lab.
When I chrono, I number my loads from 1-10, and they are shot that way at the range, then I recover the information from the chrono back at the lab and record this info into my rifle load log book at home. Loads that don't make the grade, do not get chrono testing.
 
I used to chronograph test all of my loads, ten shots of each powder charge, noting average velocity, extreme spread, standard deviation and high/low. For a while I was really into the chronograph and I did learn a lot from it. I found that shot-to-shot consistency isn't always a predictor of best accuracy though. Nowadays I just shoot for group, ten rounds of each charge fired into a single group. Best ten shot group wins and is what I settle on for that bullet/powder combination. Shots on target is what really counts.
Click to expand...

Same here. Now I test loads for accuracy first, logging case, bullet, powder, charge weight, case, OAL and primer.

Once I find a load both the gun and I like, I chronograph the loads if I find myself interested. Most of the time I don't. I chrono handgun hunting loads more often than anything anymore, because I'm usually close to max loads with those loads and I want to watch for anything squirrely with velocity.
 
I don't own a chrono , l list my loads like mmb713 . Start with weather, cold temperatures rounds shoot lower, I'll list case, primer, powder & charge, bullet & seating depth also total round count for barrel life , total times case sized. Adjustments are made based on 5-10 shot groups.
 
To Metal God's list I would add barometric pressure and relative humidity, as both affect air density and, to a lesser extent than temperature, the speed of sound. Light conditions are important for iron sights. I would also add spaces for barrel length and rifling pitch and twist direction (or simply adopt + for right-hand and – for left-hand). I would add a space for number of clicks of elevation and windage off the rifle's reference load zero, and a check box to indicate you returned it to that zero at the end of the range session. The number of rounds between cleanings and fouling shots after cleanings before measurements begin again might deserve spaces or might simply be better put in the notes.

I also wind up logging specifics for particular experiments. If I have the Pressure Trace out, I want to note the settings and to note any load I am using as a pressure reference. I often want to note either jump to the lands or the distance from the headspacing location on the case (rim, belt, shoulder datum, case mouth) to the bullet ogive in place of OAL. Cartridge runout, target type employed, average groups size for the day, sight used, firing angle if not flat. If you are shooting long range, longitude and latitude and firing direction can all factor in.

With all that data, you probably won't fill out half the spaces under many circumstances, but having them there helps serve as reminders not only for filling out, but to make allowances for each factor as you set up your gun. Filling out as many spaces as you can gives you the opportunity to use data at a later date to help identify an issue. You might have, say, irregular accuracy, but discover later it turns out to correlate to some factor on the list you hadn't thought was important before.

You also want not only the shooting log but a gun log. You want to track how many rounds are through your barrel, what trigger weight you have, note maintenance events, changes in configuration, etc.

One other thing you can do is look at databooks published for the various target shooting disciplines. A lot they have in them may translate over to your experiments and help you decide what to include.
 
You must log in or register to reply here.
Back
Top