I believe you are into the reason why it matters. It's not the velocity but the ignitial blast or shock. Maybe it changes the way the barrel vibrates. Matt
Vertical Dispersion - Weighing Primers
- Thread starter MikeMcCasland
- Start date
tom
Gold $$ Contributor
I think it almost has to (opinion of course), because I have 3 6mm's tuned right now. They're shooting smaller than anything I've ever seen before on a consistent basis, at my testing range that I've tuned several record barrels on, and all 3 chose different brand/type primers. One will always give me the "ladder shape" I'm after, more so than the others. I won't begin to venture a guess at why, I just roll with whatever the paper is telling me.
Tom
I found this in a new pack of pistol primers
looks like it was fired
But it had no primer compound in it. I’m still scratching my head over this one
https://arxiv.org/ftp/arxiv/papers/1102/1102.1644.pdf
Fig. 2 of the attachment shows blast pressure wave forms, possibly this would affect barrel vibes, generation rates of chamber pressure, and accuracy.
The attachment does not condemn velocity measurements in fact it suggests comparing velocity SD's from mean sample velocities to build load confidence. Chronographs are way cheaper than pressure transducers. The attachment did mention, "numerous loads" Super accurate scales are also expensive.
I visually inspect every primer I use with a 10X magnifier (does not take that much time - line them up and look at each one). I have never (not yet) found an empty primer or double anvil(S). But I have found some with uncentered or tipped anvils. Reading about primers tells me that the anvils have a somewhat flattened top which is intended to increase the firing pin strike area.
Seating that double anvil primer would squash the insides and all sorts of bad stuff could happen.
Fig. 2 of the attachment shows blast pressure wave forms, possibly this would affect barrel vibes, generation rates of chamber pressure, and accuracy.
The attachment does not condemn velocity measurements in fact it suggests comparing velocity SD's from mean sample velocities to build load confidence. Chronographs are way cheaper than pressure transducers. The attachment did mention, "numerous loads" Super accurate scales are also expensive.
I visually inspect every primer I use with a 10X magnifier (does not take that much time - line them up and look at each one). I have never (not yet) found an empty primer or double anvil(S). But I have found some with uncentered or tipped anvils. Reading about primers tells me that the anvils have a somewhat flattened top which is intended to increase the firing pin strike area.
Seating that double anvil primer would squash the insides and all sorts of bad stuff could happen.
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Well I haven’t won and really don’t expect to,considering the level of competitors at DC I may never win and that’s fine as well. I did manage to reduce my aggs by 3 in over the last 6 targets so that’s an improvement I look to build on.
Nice to visit with you last June at the range and hope all is well.
Jim
Alex Wheeler
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No offense intended here Mike, but I highly doubt that 99.99% of shooters would be able to shoot the difference and even if you could, I doubt that you will be able to show statistically significant results clearly showing a difference of weighing or not weighing primers. I will be watching this discussion closely to see the results. I can only imagine how much time this could add to my reloading regime if added, so potentially I’m hoping there is no correlation to be shown.Hey Guys,
I'm not looking to start a debate on the merits of weighing primers, or if it's worth the time investment. I've already decided to give it whirl, and I've weighed out 1,000 of them into groups separated by .02gr mostly (with some extreme outliers culled entirely).
I will say I was pretty surprised by a couple of observations. First, there was way more variation than I was expecting to find. I had a range from 2.28gr all the way up to 2.52gr. Most fell right around 2.40-2.46gr; nice little bell-curve.
It's not my intent to mix any weight groups; just going to load all those that weighed the same together.
That said, I'm not going to get a chance to shoot these until my next match, but as of late I've been struggling a bit with vertical in my load. It'll hold 10-ring vertical consistently at 1,000, but it's not as good as I see from some of the top guys.
I've played around with depth in .002 graduations, but can't seem to tune it any tighter, so here we are. I think my powder node is on point as I'm in the usual velocity range for my barrel length/bullet combo, and generally speaking the gun is shooting quite well.
My question: To those that have weight sorted primers, how much (if any) improvement in vertical did you see?
Bring on the discussion; my body is ready.
Components:
200.20X
N150
Lapua Plama - turned .014"
CCI 400s
.0015 'interference fit'
AMPed every firing
dave
I've read part of all these threads. There are too many. Has it been asked whether the cup and anvil weight are consistent? Has anyone weighed the spent primers to see if they are the same weight? Weighing primers for consistency under these conditions would be like grouping brass by weight when after measuring the volume, you find variations within the same grouping, or atleast I have.
Did you read post #174
its not 99.99 that cant or dont, it is ALL THE PEOPLE THAT COMPETE IN 1000 BR. it has been tested and PROVEN.
period done over.
what you BELIEVE has little to do with PROVEN DATA.
I too enjoyed @dmoran visit last June. He looked at my tuning ladder for my 300 WSM, and said pick that powder charge. That weekend I shot a 4.3 and a 3.8 HG group, both 100s. One might infer that he knows what he is talking about......
Maybe he can come out in the cold for the match at the end of this month, since I have new barrels on both my HG and LG.
Go for it. Do it. More power to you.
I suggest you do the following experiment at 1000 yards. Load 20 rounds identical, with the exception that 10 use primers on the extreme low end of weight, abd the other 10 use primers of the extreme high end of the weights. Then color the primers on the light ones with a red sharpie. Now have someone mix them up really good and put them in you loading block. Shoot all 20 on an e target without looking at the primer while you load or unload rounds. Then we can tell really quickly whether the extreme of the population in a random order blind test have any statistical significance in vertical whatsoever. I say if it makes you feel good and you have the time, then go ahead and do it. People often have rituals or processes that when done increase their confidence. I once knew a ridiculously good shooter with many wins that was convinced that he shot better when he colored the tips of his rounds green. I think the only way we could be assured of beating him was to hide his Shapie. Lol
Sandstorm
Gold $$ Contributor
Dave M. said:
So your implying the because I felt so good about my new paint job on my newly built rifle.
I went out and won the maiden competition....and no other reason.
Hmmmm..you know this game is a lot in the head anyway..and confidence plays a big part.
When I feel good I have a better chance of winning...(and I will buy that any day,) and weigh sorting
primers dont hurt none either...lol
So your implying the because I felt so good about my new paint job on my newly built rifle.
I went out and won the maiden competition....and no other reason.
Hmmmm..you know this game is a lot in the head anyway..and confidence plays a big part.
When I feel good I have a better chance of winning...(and I will buy that any day,) and weigh sorting
primers dont hurt none either...lol
Like I said, I wasn’t trying to hurt the previous posters feelings (6Bra1K) when I stated by all means, if you have the time to do it and it increases your level of confidence on the firing line, then go ahead and do it. And yes, I do believe that your new paint job on your rifle factored into you winning. It increased your confidence and allowed you to focus on your fundamentals and relax.
Dave weighing primer is not a hole im gonna go down, but you gotta admit @Sandstorm John's Mean Green would give ya a certain level of confidence.
John cleaned house his 1st match out. Weather it was the primers or paint...He looked good doing it!!
I couldn’t agree more Brett. I don’t plan to weigh primers any time soon. If you read the article several posts up, it clearly states that in order to likely prove statistically significant, one would have to be accurately measuring primer mass down to 0.1mg (that’s 0.001543 grains). Good luck with that.
dave
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