How do you straighten runout?

Dgutter

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Mar 8, 2011
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59
Precision Reloading For Long Range Hunting

I'm not sure if I agree with only neck sizing but it's his own personal process, therefore his own opinion. However, the section I quoted was what interested me as it explained the answer to the questions I had regarding bullet alignment and concentricity.
 

Gone Ballistic

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Aug 25, 2010
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At the risk of being verbally injured on this one, I'll try to answer your questions. Keep in mind that I took physics close to 50 years ago. That I was taught well and received an A in the class isn't the problem with what I'm going to mention. The fact that my memory is becoming somewhat strained over that much time is.
When pressure is applied between two opposing forces, the one with the least resistance will move first. In the case of shooting a firearm, there are alternate moving forces applied by the same pressure at different rates of sequence. First, when the primer ignites the powder, the two forces are the cartridge and the bullet. The cartridge, being the weaker of the two, expands and seals the chamber where the chamber and bolt face make it stronger than the bullet. The bullet propels forward into the L&G's and exits the barrel. The propellent has maximized it's burn rate slightly before the bullet has left the barrel increasing pressure until the bullet exits. Due to the molecular structure of the brass casing, the heat and pressure that caused it to expand and seal the case is no longer there thus, letting it cool and contract minimally. If this action didn't take place it would make it extremely difficult to extract the casing. Brass is the best material found that will expand and contract this way.lightbulb
The invention of slower burning rate powders has allowed much more precision in reloading due to the reaction timing it creates in the aforementioned paragraphs. I hope this answer has clarified your questions.
 

Dgutter

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I feel as though I have seriously high-jacked this thread. I apologize for doing so. I believe through everyones' replies and some extra research I have found the answers I was looking for.
Gone Ballistic,
You were fairly accurate when talking physics. I just graduated college with a Mechanical Engineering Technology degree about a year ago. :D The only thing you may have missed was the modulus of elasticity of the brass which is actually the largest factor in the case slightly retracting from the chamber walls.
Thanks again all!
 

Gone Ballistic

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Joined
Aug 25, 2010
Messages
720
Location
Orofino, Idaho
I feel as though I have seriously high-jacked this thread. I apologize for doing so. I believe through everyones' replies and some extra research I have found the answers I was looking for.
Gone Ballistic,
You were fairly accurate when talking physics. I just graduated college with a Mechanical Engineering Technology degree about a year ago. :D The only thing you may have missed was the modulus of elasticity of the brass which is actually the largest factor in the case slightly retracting from the chamber walls.
Thanks again all!
Like I wrote you in the beginning, I put myself at risk. I didn't want to write my reply in technical terms, as some perusers of this thread may not be as knowledgeable in the science of physics as others. I like to keep my answers as simple as possible, in case I ever have to go back and peruse what I've written down the road, I'll be able to understand it myself. Good luck with your reloading. Oh, by the way, I iniated this thread and I think it's helped me as well as many others with the answers most have given. Take care everyone and thanks for your information.
 
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