ELR LVR
Silver $$ Contributor
What I have found is The harmonics of the barrel don't change in relation to where the lands have eroded toI just watched Eric Cortina explain why chasing your lands means nothing. Must admit ,
In short, he suggested to Jam your lands back off .020. Then load 5 shots groups ( could be 3) and keep backing off by .003
You will get large group, large group, a better group then maybe 2 or 3 groups that are tight. That is your best seating depth and it means nothing with respect to the lands? He claims you need multiple tight groups that are .003 apart before you settle. Then take the longest AOL and subtract .001. Has anyone done this type of testing?
Sorry, I am new to this method and looking for input
So yes, in my opinion Eric is correct, Why chase the lands if you've found your magic seating depth?
(This may be totally different however if there is a lot of erosion and say now you're suddenly jumping .200" in which case the pressures and velocity behavior may change with the same load compared to before when the throat was newer, in this particular circumstance then, changing seating depth may help to correct load characteristics)
But once I have found the right seating depth, it stays the same for well over 1000 rounds in any rifle.
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Some people may get it into their mind that since their rifle shot best .020" off the lands....
......They need to stay .020" off the lands as the throat wears.
Mt. Cortina is helping to correct this type of false thinking
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