How many rounds of a new load?

[Chipperman]

If you are just starting a new load, how many "experimental rounds" do you crank out?

You don't want to make 1000 rounds of a load that may not work well. So how many do y'all make to test out? 10, 50, 100?
I suppose the cost of each is a factor
(as well as how different it is from other loads you've done) but there must be some general guidelines that you follow.

Thanks for the replies.

 

[bullet44]

I start with 5 rounds,if they shoot well, I
will then load 20 for accuracy test. Works
for me through the years.

 

[Marshal]

I used this procedure after I visited with the head reloading guy at a large gun shop, and it makes sense to me. He said to start with four rounds, checking the dimensions of each. Remove the magazine and chamber a single round. This is so if something bad happens, the gases can vent out the magazine well. Fire the round. If all is okay, put one round in the magazine, chamber it and fire. If taht works, put the last two in the magazine and see if the slide cycles properly. You could use more in this step if you like.

When I did it, we realized that the starting load was too weak, because the slide wouldn't cycle properly. We bumped up the charge an increment, and things started to work better.

Of course, I had a slight advantage, in that I have some acreage and could just go outside and test, and come back in and adjust. The disadvantage was that it was after sunset, and it was a little difficult spotting the brass on the ground with a flashlight. If I had to go to a range, I think I'd make sets of four or five rounds each in increasing increments, and go test those one increment at a time. After that, you can move on to accuracy testing.

 

[Calif Hunter]

I load nine rounds so that I can try 3 groups of 3 shots each. I used to load up 20, but got tired of pulling bullets! Of course I experiment more now.

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Calif Hunter www.hunttalk.com

 

[Hutch]

Depends on what you have in mind. When trying to work up a rifle load for benchrest/varmint type shooting, I load 10 of each flavor I'm trying. Back when I shot silhouettes, I'd cook up 20 or so per load.

 

[char923]

I load 20 rounds and shot a groups of 10 rounds over my chrony first then shot for group. per load

 

[beemerb]

I just worked up a load for 44 spec.I loaded 10 rds of 3 different loads.Wheelgun so no check for function but shoot all 10 to check for overpressure and accuracy.
Autos I normaly load 12 of each load.6 to check functon and 6 for accuacy.

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Bob--- Age and deceit will overcome youth and speed.
I'm old and deceitful.

 

[HankL]

It would be great to have a fireing tunnel in the reloading room but... When I work up a load for a new caliber I usually settle on 2 or 3 of the most mentioned powders showing good qualities in several reloading manuals.
Using the same case, primer, bullet combination I load 5 rounds of each powder in progressive steps from a starting point and work them up in appropriate steps.
I shoot each powder from the bench, over a chrongraph at a target. This seems to work for me. This will get you going without ever having to pull 999 rounds down. Once you settle on someting you feel comfortable with you can start making adjustments to the load again using 5 round batches. Once you think that you are in the hunt for the best load I will try 20 rounds.
HTH


[This message has been edited by HankL (edited October 30, 2000).]

 

[Cheapo]

I start with five each of maybe three different charge weights, sometimes four charge weights.

I combine group and velocity/pressure sign testing in the first outing. Fire one, inspect the case, and proceed if all is okay. If approaching max, I'll inspect every fired case as fired; otherwise I check #1 and either #3 or #5, depending on my mood.

Only BIG differences in group size may give a reliable clue of accuracy with such one-group samples. I go back and load 15 each of the two most promising loads which meet my desired velocity range. Then it's three, five-round groups to nail down the accuracy/velocity differences.

I *could* do some statistical analysis using the T-test instead of standard deviation, and get a very firm indication of how *likely* it is that the differences are real and repeatable...but I don't...yet.

The statistical gurus tell us that the test data become quite reliable once you hit 30 rounds per load tested. I choose to break them up into six, five-round groups, but I usually am satisfied with (or settle on) the results after the 15-round sample described above.

It got real interesting a while back when testing some loads in two different revolvers.

 

[Chipperman]

Interesting to see the different protocols that each of you follow. Thanks.

 

[OkieGentleman]

Get your self some of those little ziplock sandwich bags. You can load up your test rounds, put in a slip of paper telling you what you have loaded and take them to the range. When you do your test firing you can put the fired cases back in the bag for later inspection and write the results on the slip of paper. When you get home you can enter the information into you log book for later reference. This way may seem like more trouble, but you will be surprised how much trouble it is to "spill" a bunch of test loads and have no idea what is what.

 

[jtduncan]

Gentleman:

10 or 20 rounds is not sufficient to determine accuracy, reliability, or operations.

I research the most probable accurate loads and start there. I look at all of the available reloading data from several reloading manuals and make a matrix. I throw out the outdated or skewed data.

I call the powder manufacturers and then their technical service people tell me their loads and pet loads customers have passed on to them.

Then I take to reloaders using the same guns with the same barrel length.

Then I pick my starting point. Experience has shown me that I either hit it right on the mark or had to increase the grainage by 1/10th of a grain.

I prefer to work up a batch of 50-60 rounds depending on my confidence level. I then shoot at (15-20) rounds at 10 yards, 15 yards, and 25 yards to determine the best overall short and long distance accuracy.

I also take notes on round performance and look at the cases, the primer, and the bell of the case to make sure it sealed well, no gases leaked and that the case structure remained stable with no cracks, buldges or deformities.

Then I use the load that gives me the most consistent accuracy throughout.



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The Seattle SharpShooter - TFL/GT/UGW/PCT/KTOG

 

[twist996]

i usually load about 20 or so, and normally discard a few of those during the reloading...out of the 18 or so left, we check fit and function first, making sure they run through my weapon alright...after that...if they run well, i'll load some more to check accuracy, about another twenty....still new to this, so i need the practice anyway....got time and will to load 40 or so each time i want to change or modify the load...

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speak now, or forever hold your peace

 

[Bogie]

Disclaimer: I shoot benchrest. I use wind flags to minimize horizontal drift. I do not develop loads on days with an appreciable head or tailwind.

I load a handful of rounds in "off spec" brass. These are used to fire two rounds for barrel fouling. Then I fire three-shot groups, incrementing the powder charge for each group. As I increase the charge, I see the groups start to tighten up. I load hotter, and I keep watching to see where they blow up again. I shoot three five-shot groups to confirm.

Then, after I've found one or more "sweet spots," I go back, and move the bullets in and out of the case slightly, again shooting a 3-shot group for each variation. I follow this up with the 3x5 shot test...

Chronographing doesn't matter. It merely confirms that you're moving at a particular speed, and helps you figure your ballistics. I've known technically good loads over the chrono that wouldn't shoot for beans. If you hit a deer with a heart shot at 100 yards, it doesn't matter if you started with a muzzle velocity of 2400 fps or 2600 fps.

 

[Cheapo]

I also mark each case with the powder charge weight (rarely do I test loads of two different powders at the same time) and bullet type if I'm doing a/b testing of different slugs.

Use a new "Sharpie" magical-type marker, so the marking tip isn't too dull yet.

This is particularly important when follow-up testing from a semiauto. I often lose a round or two of brass until the final cleanup. It's discouraging to find evidence of a pressure spike but not know which charge weight batch it came from.