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Masters Theses the effects of flash hole deviations

From the Abstract;

Results showed that muzzle velocity and chamber pressure varied 1-4% from the control flash hole as hole diameter, offset, and orientation changed. The precision, particularly in the 3mm diameter and centered flash hole cases resulted in improvements of up to 28%. Variations in flash hole diameter, offset, and orientation do affect cartridge performance. Alternate flash hole diameters exist that improve powder ignition consistently as well as precision. Off centered flash holes increase target grouping size and result in less consistent muzzle velocity and chamber pressure values.

Intriguing to say the least.
CW
 
Browsing through the theses, I ignored the pressure and velocity data and could see from the precision data in the appendices that the centering of the flash hole had a significant effect on the precision, which is of interest to us on Accurate Shooter. That had to be a fun theses.
 
That's interesting, especially on a less than full case capacity load when the powder lays down in the case.

Browsing through the theses, I ignored the pressure and velocity data and could see from the precision data in the appendices that the centering of the flash hole had a significant effect on the precision, which is of interest to us on Accurate Shooter. That had to be a fun theses.
ing
 
Browsing through the theses, I ignored the pressure and velocity data and could see from the precision data in the appendices that the centering of the flash hole had a significant effect on the precision, which is of interest to us on Accurate Shooter. That had to be a fun theses.
Tons better than the one I presented.
CW
 
Not be a killjoy as it is a huge amount of work. Concerned about the conclusions given the type of rifles being used, targets being shown and components in the ammo.

Lots of opportunities for the 'system' to corrupt the data.

Jerry
 
I'm going to work on a go/no go gauge for flash hole centering of primer pockets.
If somebody took the time to write a 256 page thesis on this subject there's gotta be a market for it.
Supported by this "emperical" study I'll wager I could sell a few thousand of my gauges before I ran out of customers looking for greater load accuracy.
Stay tuned ........................
 
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I wonder how many actually read or skim through all those pages???? Or did they just fixate on the Abstract at the top of the thesis????

The beginning is all really well done... Obviously written by someone that has been in the science field and understands writing journals. Very much appreciated the pictures and process for drilling the flash holes and reloading. Simple but still, all good stuff.

For me, things start to go sideways around pg 53 (top corner of the report).... When I set up an experiment, my first goal is to ensure my results are consistent and accurate but also reproduceable. And the tests I would run should eliminate all other variables except what I am trying to test and prove... no?

For accuracy testing, would you choose some of those ingredients?

Then the test rifles, optics, rests and bench might be suspect as well. But hey, 10rds on a sporter Rem 788. For all the effort to drill those cases, interesting choice of test equipment dont you think????

I think the ProChrono would be a hit now with most precision LR shooters... wonder what the inherent output error on this device would be????

Wonder what that error might have on the "absolute" values of the data. wonder what the results would be if any one section was repeated oh say, another time????

The real excitement starts at section 3.6 - Data Analysis. 3.6.1 is certainly my fave... Outlier removal. Worth a read. Then there is the distance from center analysis.. also interesting.

On a second read, I paid more attention to some of the charts and yes indeed, not all columns have the same number of data points. Would make sense to only use the data that MADE SENSE

But then it all comes together when you surf through many many pages of data.. no I didn't bother to review at this point. I did like that he highlighted the data point outliers that were removed. That was quite thorough don't you think...

I wanted to see his test targets. P198 is where it starts.... you can decide for yourself on how to compare each target and ammo spec with the other.

But my takeaway from this is that I also truly like the Outlier Removal... Referee, that shot is an outlier... it is much further away from my normal group and I feel it should be removed. I will take another shot in its place so that the results are a fairer representation of the quality of my shooting (data).

Wonder how that will fly at the new sanctioned match?

Whether FH diameters make a difference or not, this is not the report I am likely to be refering to in my discussions.

But hey, it must have passed "peer review".

Jerry
 
I wonder how many actually read or skim through all those pages???? Or did they just fixate on the Abstract at the top of the thesis????

The beginning is all really well done... Obviously written by someone that has been in the science field and understands writing journals. Very much appreciated the pictures and process for drilling the flash holes and reloading. Simple but still, all good stuff.

For me, things start to go sideways around pg 53 (top corner of the report).... When I set up an experiment, my first goal is to ensure my results are consistent and accurate but also reproduceable. And the tests I would run should eliminate all other variables except what I am trying to test and prove... no?

For accuracy testing, would you choose some of those ingredients?

Then the test rifles, optics, rests and bench might be suspect as well. But hey, 10rds on a sporter Rem 788. For all the effort to drill those cases, interesting choice of test equipment dont you think????

I think the ProChrono would be a hit now with most precision LR shooters... wonder what the inherent output error on this device would be????

Wonder what that error might have on the "absolute" values of the data. wonder what the results would be if any one section was repeated oh say, another time????

The real excitement starts at section 3.6 - Data Analysis. 3.6.1 is certainly my fave... Outlier removal. Worth a read. Then there is the distance from center analysis.. also interesting.

On a second read, I paid more attention to some of the charts and yes indeed, not all columns have the same number of data points. Would make sense to only use the data that MADE SENSE

But then it all comes together when you surf through many many pages of data.. no I didn't bother to review at this point. I did like that he highlighted the data point outliers that were removed. That was quite thorough don't you think...

I wanted to see his test targets. P198 is where it starts.... you can decide for yourself on how to compare each target and ammo spec with the other.

But my takeaway from this is that I also truly like the Outlier Removal... Referee, that shot is an outlier... it is much further away from my normal group and I feel it should be removed. I will take another shot in its place so that the results are a fairer representation of the quality of my shooting (data).

Wonder how that will fly at the new sanctioned match?

Whether FH diameters make a difference or not, this is not the report I am likely to be refering to in my discussions.

But hey, it must have passed "peer review".

Jerry
The tester might have been a democrat!
 
Come on Jerry...give the author a break. It is a Master's Thesis after all, not a post doctoral paper culminating in many years of research by the author, and various members of a lab, on the topic and associated issues.:) I view Master's research as a basis to see if something is worthy of further investigation and the beginning steps of proofing a model. I commend a young student for his attempt to research an interesting issue. I would also, as your comments are suggesting, NOT take the conclusions as gospel or make any assumptions based on this research. If the same conclusions were reached in a couple of different models by a few other independent researchers then...MAYBE...they are on to something.
 
You have to realize that this is done by *students*. It's not peer reviewed, Bob McCoy grade work. (With all due respect to German Salazar, his very interesting article on primers is not really something an academic or serious engineer would cite). That said, it's still interesting. However, with a strong caveat that I haven't made it all the way through, it seems like the conclusion is pretty much "it doesn't matter much" (at least when you read it with a critical eye). At best, it needs more careful study to tease out the variable in question.
 
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Students graduate to build space shuttles, nuclear bombs.... and bridges don't they?

This thesis is published and logged into the Missouri University of Science and Technology as reference material... Up here "university" is usually reserved for institutions of the highest levels of education and science but maybe different below the 49th????

This gent used this research "In Partial Fulfillment of the Requirements for the Degree..."

MASTER OF SCIENCE IN EXPLOSIVES ENGINEERING [Scared yet?????]

and apparently it was reviewed and approved by 3 others including his Advisor. Cause it says so on the Thesis title page.

All with cooperation with Fiocchi.....

Ummmm, some fun huh Bambi?????

Jerry
 
Jerry, in my previous life I reviewed thousands of 'scientific' publications, many of which were various thesis papers or publications of offshoots of such in peer reviewed journals. Some of the literature I read bordered on comical, yet many of these same authors have gone forward in their respective careers to contribute greatly to the knowledge base in their fields. They have to start somewhere:). If it was work done in fulfillment of a Doctoral degree I would throw down the BS flag 'quick fast in a heartbeat'.
 
The title of the theses is "The effects of physical flash hole deviations on factory-grade rifle ammunition". I believe he demonstrated that, using the equipment available to him. Dropping the outlier datum points is OK, seeing as how he identified them.
 
It beat my efforts as a student. My senior project was a novel take on a pressurized beer keg. Our professor said to us after our presentation (which included bribes of beer, to no avail), and I quote - "I think what you guys built is a bomb." And I *wasn't* in an explosives engineering program. Then I went on to build space shuttles for a living. Literally.
 
Nice read. It would be interesting to see similar studies about barrel harmonics.
There was a master thesis done by Huntsville University students back in the early 90's. It concentrated on longitudinal vibrations of rifle barrels. It was presented in a American Institute of Aeronautics and Astronautics conference.
 

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