If I had one of those fancy Cartridges of the World books, I could look it up as they have the (supposedly) exact specs. But I don't.
Re. using the taper crimp die to rectify anomalies, perhaps we are talking about two different things. The case distortion that I speak of imparted by the carbide ring in the sizing die is down near the base of the brass case, about a quarter of an inch up, just above the web area.
There is another unsightly case deformity that occurs and that is case bulge when the bullet is seated. This is a result of a slight mis-match between case wall thickness and bullets used. It could be that some taper crimp dies might ameliorate this bulge, but the CH brand that I've used for years does nothing for it.
Case bulge resulting from bullet seating is hard for hand loaders to eliminate completely on some pistol cartridges. In my experience, it is more pronounced and apt to be encountered the smaller the caliber. .32 ACP can be troublesome for those of us who are crazy enough to hand load it. .380 ACP and 9mm are less so, but it does affect them. It usually doesn't bother much in .45 ACP but does happen.
Reason: Ammunition manufacturers engineer their components so that the brass case and bullet are entirely compatible with one another. They don't necessarily use the same components in production that are available to hand loaders. You can see this in the thickness of various brands of cartridge case brass. In my own experience, RP pistol brass is usually thinner than other makes. For example, many RP cases in .32 ACP won't even hold a lead bullet in tension. I've had the same experience with some RP cases in .45 ACP, insufficient bullet pull.
RP isn't necessarily using oversize bullets in these thin-walled cases. More likely, they are making a round using a "normal" spec bullet (or close) but their equipment is such that it will assemble a thin-walled case to a normal bullet and do it with normal bullet pull.
One explanation for this is that considering the enormous quantity of brass cases used in manufacture, the savings in material adds up to a considerable amount.
I'll give you another RP headache. .38 S&W (not Special), of recent manufacture. One time I tried to use some pulled lead bullets from some RP factory ammo. When I tried to seat the bullet in a sized case, it fell right into the case without any friction. At first, I thought perhaps I hadn't gotten one of the cases sized, so I tried another. Same thing. Then I miked the bullet and the diameter was (if I remember correctly) something like .006 smaller than spec, which for the .38 S&W is .360.
I came to the conclusion that RP intentionally undersized these bullets as so many of these cartridges would have been fired in old, top-break, cheap, turn-of-the-20th Century revolvers. It was an easy way to bolster defense in a liability case. Much like they load 8mm Mauser ammo significantly below its potential. It certainly didn't do the reputation of the old revolvers any good to cause them to be fired with undersized bullets.
On the opposite end of the spectrum, the thickest brass cases that I've encountered were headstamped AMERC. They come from a company in Florida. Their brass is soft and thick. In my own experience, it's basically unusable for hand loading. Talk about your bullet bulge. I've seen 9mmP cases with the unsupported head section nearly blown out. .32 ACP's were un-loadable. .223 Rem. case mouths very thick. So with overly thick brass, what adjustment in component could be made to allow it to function through its first firing but reduction of bullet diameter?
In the matter of overly thick brass, the manufacturers might be using a bullet that is, say, .0005 or .001 smaller than spec in order for the ammo to be properly assembled at the factory and function through a first firing. Then when hand loaders go through their motions and use true size bullets sold in boxes of 100, they get the case bulge when the bullet is seated. Usually, these will function just fine as chambers normally aren't that tight.
Not having to do with pistol ammo but germane to this issue is the following. I've had pulled bullets from Speer .30-06 factory ammo that measured .309. Not much off .308, but an illustration of how factory ammo can vary. After all, we usually just shoot it, rather than analyze it and never know about any deviations for whatever reason.
Back to the issue of case bulge from bullet seating, hand loaders can minimize this with careful case selection. By that I mean by brand, not individual pieces. We cannot do much about tweaking bullet diameter without going to the trouble of re-sizing them. And then you might be under-sizing a bullet to the bore. For a mostly cosmetic issue, I don't think it's worth the time with pistol ammo.
With rifle ammo, there is always neck turning.
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