Little bulge when seating .45 ACP

[David2011]

It's been mentioned but it's hard to emphasize enough to not over crimp with the taper crimp die. The mouth opening may have a tiny burr (we are dealing with thousandths) so measure just below the mouth of the cartridge with the tip of your calipers. Starting with the taper crimp die doing nothing and slowly adjust it downward until it irons the bell out and gives an OD of .471- .470. After verifying with a few rounds that you're getting the desired OD, pull and measure a couple of bullets to verify that they are not smaller than .452". Any smaller and 1) accuracy degrades and 2) you will likely see leading appear. I cast my own and this is what works for me. Chances are "your mileage will not vary much" on this particular subject.

David

 

[wingman]

I seat and crimp in separate operations using a Lee factory crimp die, others will tell you it's not necessary but I prefer it, I use the 230 plated bullets, my
reloads look factory no failures.

To a new reloader I always say take your time, reload only small numbers at first make sure you try them at the range prior to reloading large batches, then when you hit a good combination go for the big numbers.

 

[GLOOB]

If you want a real eye opener, shoot at 75-100 yards. You don't even need any paper, unless you're really that good. Just pick a spot on a berm and watch where your bullets impact. Compare that to your jacketed ammo.

When the base of a soft bullet gets mashed in, the bullet might still shoot straight as you could hold a gun out to 15-20 yards. But things go wonky at an exponential rate, after that.

Before fixing my expander issue, I thought plated bullets shot fine on paper, at paper shooting ranges. But trying to hit a beer bottle at 50 yards with my affected calibers was pretty much like playing the lottery. I actually thought that some of my guns just weren't as accurate as others, (because some of my dies didn't need any help). Even though whenever I shot jacketed bullets, I had a "better day," I didn't want to believe there was that much difference in the bullet for a long time (because I'm cheap). But expanded properly, my plated bullets shoot straight as jacketed, as far as I can tell. Which means a bottle at 50 yards is game on with just about all my handguns. No, I can't hit it every time, but it's not complete luck when I do or don't! OK, I might still believe my Glock 21 has some magical properties; that's hard to shake when a gun has shot right where you expect it to with every kind of ammo you have put through it and has never let you down in any "bet you can't hit that..." situation. But now I see the same potential is there in my other calibers, too, and part of that magic was in the sizing die.

Even better, I now get the same accuracy and no fouling using cast bullets (and out of most of my semiautos, I get virtually the same amount of smoke as with factory jacketed ammo; meaning it's there, if you look hard enough).

So if you have a coke-bottle bulge and you are loading soft bullets just fine, or if you are using an FCD and it's not affecting your ammo, maybe you should not try this and just keep on shooting and enjoying your ammo for what you do with it. But if your die is as tight as the OP's, I wouldn't count on any magical experiences with plated, coated, or cast bullets. If you want to keep the magic out of it, then try the 100 yard test.

 

[kwg020]

I run my finished .45 auto cartridges through an RCBS trim die. The finished case measures between 0.470 and 0.471 and the bump is gone. I do this after taper crimping.
kwg

 

[entropy]

I think you're worrying about a non-issue. If your finished rounds will fit in your pistol barrel's chamber easily, they're fine! Called a "plunk test". If they drop in and go "plunk", choot 'em!

What he said. I keep an old 1911 barrel on my loading bench for just such a purpose.

 

[Mad_Charlie]

So, basically what we are talking about here is "neck tension" with straight wall pistol cases, what specification would you recommend Mr. Gloob? Particularly for .44 mag cast at max loads at 18bn. and mouse fart with soft lead?

Right now my combination gives me .003 (RCBS stock), but I can make an expander any size I want.

 

[GLOOB]

(Ok, I edited this many times as I thought through my reasoning. And I'm glad you asked, because I filled in my theoretical model quite a bit.)

In my estimation, which is worth at least twice what you are paying for it, I figure the expander ought to be about 1 ten thousandth of an inch smaller than the bullet at the case mouth. And then starting about 2 tenths of an inch from where the base of the bullet seats, it should start to taper to 3 ten thousandths of an inch smaller than the bullet and should reach at least as deep as your bullet will seat by the time it adds just a little flare. And the flare should be about 3 thousandths of an inch larger than bullet diameter. And that would be the same answer, no matter what you are shooting, although with jacketed bullets you are probably just as good going up to a couple mils smaller.

Note that this answer does not depend on measuring the brass, at all. That doesn't matter in my book, whatsoever. As long as your size die gets your brass undersized, a bit. Or maybe at least enough to see a bulge with your bullets, anyway. That is all you need to know. These expander dimensions are what I find will work with such a tight sizing die. If your sizing die is a little loose, already, then these dimensions may be too big; my theory is that this is due to the larger die not getting the case small enough, and that the plug will only be cycling the "spring" of the case an extra time, increasing the "set" that a new spring takes, weakening what was already less than full neck tension to begin with. In this case, it appears like you might retain more of that tension by using an undersize plug (or just a flare die, because this case doesn't need to be expanded at all). In a tight enough case, this plug is making a new "spring" by redefining the inelastic boundary of the metal. And because it's pushing the brass in the opposite direction from the sizer, it's ok to get up to full bullet diameter. The springback is going to make the case smaller by the exact amount it needs to get full neck tension, and no more. And any set that the new spring is going to take is going to act only in the direction that makes the neck tension tighter. So it's kinda like either you need an expander at all, in which case these dimensions will work. Or you don't need an expander, at all, in which case this will probably hurt neck tension. But I contend that in no case do you benefit from an expander that is 2 mils smaller than the bullet over the one or the other: a flare-only die or this monster oversize expander. It's a kinda-sorta compromise that just might sorta even out a case that might be too big at the casemouth, but too small at the bullet base, due to increasing thickness of the brass, but it can't open up the base enough to be optimal for soft bullets.


Footnote: you WILL notice that the bullets are easier to seat, but if you compare the neck tension of the bullet by whatever method you use to test that, I predict you will find the neck tension is essentially unaltered. Again, provided that your size die is tight enough to begin with.