Originally Posted by mo
I pose this question. My buddy I and sort our ammo in f-class .001 .002 together then we separate .003 and .004. We see no difference between them. I hit the x ring just as many times with .004 as I do with .001. The question, if you're seating your bullets 20 to 30 thousand in the rifling, and your chamber is cut perfect wouldn't your .004 run-out go to .000 or .001 chambered?
Two campfires here, and they're barely within sight of each other:
1. Those who run with loose chambers and very high pressure loads. They Jam everything, FL size everything, neck turn nothing. These tend to be competitors using turn-key cartridges & guns.
2. Those who run with tight chambers and lower pressure loads. They put every effort into precise control over their loaded ammo. Again competitors, and varmint hunters, often using wildcat cartridges.
Hard not to argue for/against either, and they frequently banter in forums on a wide range of reloading subjects.
One of them is RUNOUT -vs- CONCENTRICITY, and their affects.
They are completely different, but definitions aside, they boil down to this:
-Concentric means a bullet points with case centerline. Bore centerline might be achieved provided headspace is zero and there is enough chamber clearance to prevent misalignments from runout. This means FL sized and jammed.
-Low runout means a loaded cartridge is straight, and concentric, independent of chambering. This is as good as you can do for rounds seated OFF the lands. But tighter clearances in every respect are in order to get bullets pointed down the bore centerline. It's more work for sure.
I don't believe it's easy to prove that either improved concentricity, or reduced runout, would always provide gains.
I'm sure it's easier to demonstrate otherwise.
Reason being, like all things in reloading/shooting, it's an abstract.
One guy shoot's great with weighed charges. Another shoots great without weighing charges.
Hell I work with a guy who's 30br banana's can clean my perfect 6br ammo's clock at 200yds.
Is it because my fitted necks and fitted coaxial throat, and TIR below .0005 are a bad thing?
Or because of our stocks, scopes, bullets, & barrels?
Could I convince him that he needs straighter ammo -like mine?
Not while he's cuttin ragged holes next to my daisies...
He jams & FL sizes,, No trimmer,, No scale,, yadda, yadda
I'd be ashamed to narrate my efforts!