9MM Primer Test

I believe it will be an honest representation of what the average hand loader will find in the course of their work. There are just too many variables to try and control every aspect. I do sort my brass by headstamp, just to try and remove some of the variables and achieve some form of uniform consistency.

Just as one boring rainy night I sat at the bench and weighed each bullet in a box of 500 Xtreme 100gr FP 380. Mostly out of curiosity than anything else. Of that box I found a variance of 1.4 from the heaviest to the lightest with the majority of them between 99.7gr to 100.2.. I recall the lightest was 99.3 and the heaviest was 100.7gr and there were only 3 or 4 of those. I did separate them into 5 groups, all below 99.7, 99.7 - 99.8, 99.9 - 100.0, 100.1 - 100.2 and then everything above 100.2.. When loaded it made no difference in my groups.

kmw1954 said:

Go argue with yourself. I'm done with this one.

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Thank you...

I believe his point was that there are allowable tolerances within the manufacturing process. as such, no matter how hard you try, they will not be exactly the same. if they are, it was from luck.
and brass ball valves are a good example of having to work within an "allowed" spec.

for this test, im certain that sorting by weight would be plenty good. but im just some guy

Walkalong, thanks for putting in the effort to satisfy our curiosity about the velocity differences between all the different primers. Looking forward to the test results. Are you planning on testing accuracy at the same time? It will be interesting to see if there are any measurable difference in the groupings.

fxvr5 said:

Walkalong, I'd suggest a change in your method. It looks like you're selecting FC cases from various fired brass you had around. They could, and probably are, from different production lots/runs. This potentially introduces a difference in case volume, which could affect your results, and could lead you to a false conclusion in your primer comparison. That means you've wasted your time and money and/or led you to believe something that isn't true. That's not the best method for a science experiment.

I suspect that weighing them is not a reliable method to estimate if they have the same volume. Volume seems like the critical variable here, and if you want to ensure they are the same volume, you have to measure volume, not weight. Whether they weight the same does not matter. Whether they have the same volume does matter.

I'd suggest using new cases from the same lot. Buy new brass.

Any experiment worth doing is worth doing right. If you do it wrong, you won't be able to trust the results, and you're efforts/time/money have been wasted.

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If he was doing one with each primer I see your point but he is doing ten of each and giving the average, that's going to be close enough for most of us.

Could turn this into a casual long term test also. Shoot these and record results and save the cases, then when the opportunity arises load them the same way and repeat. Also this will rotate the brass randomly with the primers. Then compare the results of the two tests.

My downfall is with new loads I save targets. I have stacks of shot targets with all kinds of scribble on them. The one definitive thing I've learned is there is nothing wrong with my handloads, it's all me! Good days, poor days, days I should have just stayed home.

Not only that, but there is no such thing as a perfect test. Purposeful, useful, entertaining, yes. Perfect, never. Nothing perfect about something scientifically sound either.

But there are right ways to do things and wrong ways to do things. Why knowingly choose the wrong way?

fxvr5 said:

But there are right ways to do things and wrong ways to do things. Why knowingly choose the wrong way?

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I do believe if you are so concerned regarding the internal volume of the cases, I'm sure Walkalong would take the cases that you send to him to use. Provided, you would need to find cases from the same lot, and not only that but you would need to measure internal volume of each one and sort for consistency.

Or you could develop your own test and post the test/feedback here. We can never have too much information.

I would be very curious to compare and contrast fxvr5 results with tighter controlled cases, vs Walkalong's findings.

The small weight difference may just be the length. Most vary by 0.010", but it does not impact the internal volume. You could very simply measure a light one and heavy one and see if the lengths are the same. I would bet not, nor does it really matter. Most any thing mass produces is going to have a tolerance, if not we could not afford them. One off's custom machining is very expensive.

fxvr5 said:

But there are right ways to do things and wrong ways to do things. Why knowingly choose the wrong way?

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Because.......................it's his test, we live in free America and he can, or.....its plenty good enough for who and what its for. Who cares? That's way more than my mother gave when I questioned her motives as a child.......for her it was just .....because.

Right or wrong? That's a bit strong.....I like good or gooder.

I'll add my thanks to Walkalong for his test of various primer brands. No it won't be a laboratory test with high tech equipment rivaling NASA and there might not be pressure curve/time charts available, but I'm more than sure the results will be well worth his effort for most of us...

Looking forward to results...

fxvr5 said:

But there are right ways to do things and wrong ways to do things. Why knowingly choose the wrong way?

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Perhaps you could enlighten us with the "right" way?

OK, so everything in the test is not "perfect"
I still think it's a good test and that, the results will be interesting and helpful, and I appreciate Walkalong taking the time to do it and post the results for all of us.

I look forward to seeing fxvr5's precise and perfect test results. I'm holding my breath.

kmw1954 said:

What intrigues me more is the weight variance he's shown and the thought hitting me how at times people on forums respond that they weigh check completed rounds to try and find if they've missed a charge. I always respond that those people must be weighing every component and sorting BEFORE they ever start loading. Just by looking at this data and seeing a 4+gr variation in just the brass with the same headstamp debunks that practice. Many pistol loads use only 4 grains of powder so how would one know if a powder charge was missed or not? I know for a fact that I am not about to start weigh checking, sorting components before I start each loading session. At least not when I'm loading 200/300 pistol rounds at a time, and for many those are small volumes.

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I'm one of those people. I sort by headstamp, and favor those headstamps that have a narrow weight range. One of several reasons I prefer Starline is because they are consistent enough, in my experience, to make this work. There are other brands that I use only at great need, because they don't.

Interestingly, I had the weight check work for me in the last 2 weeks. Except, because I had recently changed a component (to powder-coated bullets instead of plated), I chalked up the short weight to probably just being a projectile weight issue. I marked the head of the case with a marker slash, but did not pull the round down.

That round later became my first (and, I hope, last) squib.

I still believe this will shine light in a real world way. The same way most all of us practice when we reload. I am quite certain that I will not be using brand new sorted brass every time I load. Most likely it will be most don't even separate their brass by headstamp at all. With that I'm even more certain that I am not going to separate brass, weigh sort every bullet and weigh check charge and then measure each and every pistol round before I put it into the gun.

I do not own a chronograph but then I don't have anywhere I could even set one up. The indoor range I shoot at most of the time is not going to allow me to set one up. So I do not have access to that information from my loads. Best I can do is go by the way they feel and how well are they grouping which is all subjective to me and how I feel that day. I am not the greatest shot but I am good enough to know when a round is working well or not. Do I care if one round is 50fps faster than the next? NO! That might matter to a long range rifle shooter but I doubt it amounts to a hill of bean to a 10yd to 25yd pistol shooter.

Walkalong, run your test I will be looking forward to what you find. However unscientific it is.

ATLDave said:

Interestingly, I had the weight check work for me in the last 2 weeks. Except, because I had recently changed a component (to powder-coated bullets instead of plated), I chalked up the short weight to probably just being a projectile weight issue. I marked the head of the case with a marker slash, but did not pull the round down.

That round later became my first (and, I hope, last) squib.

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Curios, how did you find that one round that was light? Do you weight each round before storage? If so how many do you load at a time? I know I would not sit and weigh check 100/200 pistol rounds before I box them up let alone how some here are loading 500 or more at a time.. Also I've learned that pistol bullets can vary by over 1grain from high to low within a box. But again this is a whole different discussion.

kmw1954 said:

Curios, how did you find tat one round that was light? Do you weight each round before storage?

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Yes

kmw1954 said:

If so how many do you load at a time?

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Depends, but in this instance I was cranking out rounds on a 650 for use in USPSA. I use QC'ing (weighing and case-gauging) to break up long loading sessions. In this case, I was filling an ammo can. Several hundred rounds were made that day.

kmw1954 said:

I know I would not sit and weigh check 100/200 pistol rounds before I box them up let alone how some here are loading 500 or more at a time.

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I, however, will and do. I'm a nut that way. And I just got verification that there is benefit to it from my (scary and distressing) experience.

I love doing these types of load evaluations where you start comparing individual components. I have done a few of these non-scientific tests, and always came to some conclusion based on the trends that I saw. One test I did was in 357mag with different headstamp cases to see if some will be stickier during extraction. Another test though not as comprehensive as Walkalong's test, also tested a few different primers. My test was with 40s&w, and definitely produced some trends/results. I am definitely looking forward to the results, especially how the magnum primers perform vs the regular primers.

ATLDave, thank you for that candid response. I will say you take it much further than I do. While I do use a Pro1000 press I go slowly, look into each case before I hand place a bullet, check weigh in my mind way more frequently than is necessary, like very tenth one or sometimes I weigh 4 or 5 in a row. I also look at each primer as it comes off the press before I but it in the box. So far all has gone well.