vzerone
Nothing condescending or inflammatory there in my post. I was responding to runfiverun's remark which some might consider "inflammatory". However, I do not consider his remark that but just his usual snide remarks. Other than that my remarks are facts based on what was said in the other thread.
The point is DrB claimed all sorts of "credentials in Ballistics" but it became quite apparent his knowledge on the topic was lacking. I do have a college degree but have learned far more from practical experience and learning by doing/experimenting than I did in college. What I did learn in the science classes I took was how to properly conduct an experiment with a sufficient sampling so that a correct conclusion may be reached. I know many highly educated people, including PHDs, who could not pour water out of a boot with out cutting the toe off to do it. Conversely I also know many highly educated people, including PHDs, who can and do use their education and knowledge correctly. I have been studying ballistics since I was in high school. I have continued through the years and have invested heavily in the study to be able to conduct and measure the results of tests/experiments. What I present is based on facts from that testing.
Did Dr. F. W. Mann have a PHD in Ballistics? No, he was a medical physician (general practitioner including obstetrics) With a degree in science. He began studying ballistics as a young man because he was intrigued by the bullets dispersion on target (what we call groups). He learned through tests and experimentation. We are fortunate for the results of his work.
When I first mentioned preliminary testing was indicating too much RPM might be the root cause of inaccuracy at high velocity on this forum long ago I was challenged by many on this forum. I was told by several "old sages" here that I must prove the theory. I went to great lengths of time and expense to prove the RPM Threshold was valid. Most knowledgeable shooters here believe that proof and believe the RPM Threshold is valid because they have experienced the effect of too much RPM resulting in loss of accuracy also.....at the RPM levels predicted. If you still doubt then you also are more than welcome to present actual test evidence proving otherwise. However, unless you actually post real test results with sufficient groups such as I have at 100, 200 and 300 yards then be prepared to have your results questioned. Posting what someone else says they have done, especially on the internet, without the actual test results is meaningless. Also posting cropped photos of a supposed 4 shot group at 312 yards by a relative is questionable.
You can indeed push up the RPM Threshold. I have also proven that not only on this forum but you can still find the information on the NOE Forum. However, even though you can push up the RPM Threshold you will still bump into it. Several claim by using Cu in the alloy and heat treating they attain "accuracy" at 2400 fps +/- from .308W ARs or similar rifles with 10" twists. For sake of argument let's just agree with that. So then if there is no RPM Threshold then why are they not pushing 2500 - 2600 fps from the .308W.....it certainly is capable. The RPM Threshold of 120,000 to 140,000 RPM is the "magnitude and intensity" based on the use of bullets cast of ternary alloys. Adding Cu, PPing, and it appears some PCing are some methods to push up the RPM Threshold.
However, all of this has nothing to do with the OP's question. I'm all for getting back on topic.