All processes have end goals, and accuracy (or rather precision, meaning group size) improvement isn't always that goal.
Sometimes you have to clean as part of a process, like removing sizing wax or other lubrication at different stages of neckturning or wildcat case forming.
Long term storage, putting damaged or dirty range/once fired brass into service, processing new brass, changing brass from one rifle to another (
), all of those can be reasons to clean cases differently. There's about as many reasons as there are rifles.
I use all of the above options depending on the situation.
- Some precision loads go chamber-press-box-chamber with zero cleaning.
- Sometimes I completely "reset" brass with a long SS cleaning and dunked in alcohol after to remove everything - carbon, oil, etc
- The resets are usually when I change something big or restart a load workup. Sometimes just because after 5+ firings they're grungy and I just want to measure them, check the pockets, case web, shoulders, stuff like that I don't want to get covered in carbon doing it.
- Usually I toss brass in a vibratory tumbler either before depriming or after sizing. No reason other than it's the easiest process and shooting suppressed the cases can get so dirty I don't want to run them up into the die like that.
- I use ultrasonics on parts more than brass, but very stubborn primer pockets get the ultrasonic. Mine is very small so I can't do big batches.
- Walnut is basically magic at polishing anything, I do more not-gun stuff in walnut because it's just a plain handy tool to have for around the house and garage stuff.
TL: DR time: Y'all just move along if you don't want to read a musing on precision and case cleaning.
As far as impact on precision, it's part of a bigger process. You can eliminate case cleaning as a variable in multiple ways - doing it the same way every time, not do it at all, even completely scrubbing the cases to bare raw metal each and every firing might be a good option for someone. All that matters is that it
does not show up on the target.
I make a lot of assumptions around my cleaning methods (I think we all do) and center my logic in making those assumptions around them not creating a negative impact - if I can still shoot well after what I do or don't do, ipso facto what I did is not bad, or to go one step further instead of "bad" I'd say it's not my limiting factor. That's a
negative confirmation, which amounts to saying that something hasn't happpened ..... yet. Not saying that it can't happen still.
I won't make a positive statement correlating cleaning and precision on target. To make a positive statement correlating the two there would need to be a whole lot of evidence to support even practical experience. Unless the test is structed all experiential evidence is merely anecdotal.
My experiential evidence is that case cleaning doesn't show up in my targets. That mean's it's not
my limiting factor, but it could be for others.
I do have hard data via the AMP press showing there is a measurable impact to seating force resulting from different cleaning and neck lube methods. But what does that extra seating force mean? So far - nothing.
I cannot correlate increased seating force to anything. I'm starting to gather data about this - so far only one test of 100 rounds from a 6.5 CM. The first test is showing better consistency in seating force results in a smaller group size - groups match by seating force shot very slightly better than unmatched groups (intentionally varied), but not in a robust statistical and quantifiable manner because it's a small number of shots. Also, matched groups shot as well as each other, even if the seating force varied considerably between the two groups. Interesting, but nothing there yet. I'm more likely to change how I quantify group size than change a loading process based on what I've seen so far. Mean Radius is a much more involved comparison than simply looking at the two shots apart furthest or greatest distance from POA, but it's much more informative.
Even if groups do shrink with more consistent seating force - that does not imply neck lube or case cleaning being causative to the reduction. Could be hardness or spring back in the brass, could be lighter force happens when bullets seat straighter, could be inconsistently high or low force is due to neck thickness variations. Case neck state is a variable and might make an impact, but there are a large number of variables that probably matter more.
