As you may know, I have made some posts on cleaning range brass by boiling it in water and two squirts of lemon juice. While this initially looked like the way to go across the board, I had problems with 9mm brass sticking in the carbide size die and bending or tearing the rims off.
Since then, I have done some additional work, and thought I would post the results. To begin with, let's compare the tradition method of brass processing and the boiling water and lemon juice method:
EDIT!! After boiling my cases with water and lemon juice, I DO rinse them in plain water to remove any lemon juice residue.
With the traditional method, you pick up the range brass, and unless it's rained, it's fairly clean but may have some tarnish on it from powder residue in the chamber. If it's caked with mud from a rain, it's best to wash it off before you put it in the tumbler, or you'll just add that much more dirt to your tumbler media. Hopefully you are leaving the fired primers in the case, because picking walnut shells out of the firing pin hole is a major PITA. Then you put the cases in the tumbler, and after 5 - 10 hours or overnight if you forget, the cases come out nice and shiny. Then if it's a straight walled case, you run it through the carbide size die. Now, when you do this, there is microscopic residue on the shiny case from the tumbling that actually acts as a lubricant in the die, but the particles get smeared along the case during resizing, so they get LESS shiny than they were when they came out of the tumbler. The picture below shows pairs of cases, with the left case being a resized boiled lemon juice case, and the right case being a tumbled and sized case.
Now, with cases processed with the boiling method, you dump in the cases into the boiling water and lemon juice, and magic happens before your eyes almost instantly. The cases become factory fresh and shiny as long as they are being boiled, but then when you drain them and wash off the residual lemon juice they get less shiny after they are dried. Still, they are really clean, and when you run them through a carbide size die they actually get MORE shiny because of the polishing action of the carbide on the brass case wall. Now, with 45 ACP brass there is no downside, and the cases resize just fine. I suspect the same is true for 38/357 and the 44's and 45's. With any necked rifle or pistol case (like .223 or 357 Sig) you have to lubricate the cases anyway, so resizing those is just the same as doing tumbled brass.
The one problem that comes in is resizing 9mm brass, and the boiled brass definitely resizes harder than the tumbled brass. Now, some of you may have noticed that 9mm brass resizes a hell of a lot harder than a 38 Special or 45 ACP brass, which always seemed strange to me. It has finally dawned on me why this is so, as the 9mm case is one of the few that is TAPERED. That means that the mouth of the case is a smaller diameter than the base of the case, so when you reize it the case is essentially getting resized TWICE in one press stroke. That's also why 9mm carbide cases are a lot more expensive, because they are not just a simple carbide ring that just sizes the whole case to a constant diameter. So you need a longer piece of carbide, and you also neet to grind the taper into the carbide, which is a bunch more work and thus costs more.
Now, with 9mm cases boiled in water and lemon juice, the cases are REALLY clean. You can resize several hundred cases, and your thumb and forefinger of your case grabbing hand will stay clean, as opposed to the black fingertips you get with several hundred tumbled cases. Unfortunately, if you do the resizing step like you normally do, which is ram the case into the die, and then haul it back out with a nearly continous press stroke, the 9mm case rims can suffer and or a case can get stuck in the die with the rim torn off. It should be noted that this is also dependent on how powerful the load was, and with mild loads the 9mm cases may still resize just fine. With "Tim Warner" 9mm loads, however, the case can go into the die extremely hard.
The fix I have found found for this, which is not perfect, but does work, is to push the 9mm case up into the die, and depending on how hard the sizing pressure is, wait from 1-4 seconds until you pull the case out with a firm and steady pressure. If you do this, you can get 99+% of the cases out of the die with the rim intact. This definitely makes the resizing step more tedious, and you'll have to decide for yourself if it's worth it to do it this way rather than spend time tumbling your brass. Obviously, this treatment won't work with a Dillon press at all in 9mm, but with 38/44/45 cases it will probably be just fine.
As far as my own viewpoint, I'm willing to do this to get selected headstamp cases (Win, FC, R-P, and PMC) into my case stash, and from there on out my 9mm loads tend to be on the mild side, so resizing will be fairly easy, and I may not choose to clean my brass every time with my own handloads.
In general, boiling cases in water and lemon juice when you get back from brass picking is a good idea, because you are getting the most crud off your cases at the top end of your reloading cycle. That's worth something right there. For a variety of straight walled and most bottleneck cases, this case cleaning method is far quicker than taking the 6 hour tumbler route, and doesn't have any downside. For 9mm cases, it will depend on how you reload and what the strength of your reloads are to decide whether this method is for you.