gloob
05-29-2015, 03:30 PM
Gloob's unified theory of bullet expanders - why some folks need em, and need them BIG, and why some may think a 2 mil under expander is doing something when it's not, and why some people use the Lee Universal Expander with good success. I'm hoping to get some feeback/criticism.
It is no surprise to any members active in this forum that Gloob has some strange ideas, and he has an annoying tendency to spout his own opinions as if they are fact. Well, I formulated a pretty interesting and comprehensive "treatise" on what is the perfect size for an expander, the other day. And with what I came up with, you will may need an oversize plug, and you may not. That is nothing new, you say. But maybe there's more to it. Anyhow, I came up with some of the details in response to a query/challenge I received, after I had spouted off a bit concerning my ideas on another forum. And here is my response, mildly edited:
************************************************** ***************************************
http://images.thehighroad.org/statusicon/post_old.gif Yesterday,
11:16 PM
#32 (http://castboolits.gunloads.com/showpost.php?p=9921022&postcount=32)
GLOOB (http://castboolits.gunloads.com/member.php?u=53020)
Member
Join Date: September 16, 2007
Posts: 5,675
In my estimation, which is worth
at least twice what you are paying for it, I figure a proper 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. So basically, the expander should be about the
same size as the bullet.
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 a tight sizing die.
If your sizing die is a little loose, already, then these dimensions will be too big!
But no worry, because in this case, you do not need an expander, to begin with!
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 should 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. A two mil under expander
is either acting as a perfectly good flare-only die or an inadequate expander.
If you wanted to make the perfect mouth flare die for a caliber, which will never
reduce neck tension, and which will at least make a small improvement on a grossly
tight case then 2 mils under is, indeed, the ticket and there is a technically sound
reason that this size is the default. It's because most of the time (for the average die)
it is only flaring the mouth, anyway, and it needs to be 2 mils under to not ever interfere
with neck tension. But if your sizing die is tight, you will do worlds better by using an
expander the same size as the bullet. So if you need to make the jump up, you ought to
make it all the way. There's no point in getting somewhere between the two. If your die is
tight, a -1 or -2 mil expander won't give you any more neck tension than a -0 expander, but it
will have a much greater ability to swage bullets.
http://images.thehighroad.org/smilies/evil.gifhttp://images.thehighroad.org/smilies/cool.gifhttp://images.thehighroad.org/smilies/evil.gif
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. In fact, using a full bullet diameter expander with a
tight size die will give more neck tension than ammo made with a "good" sizer
that doesn't require more than a -2 mil expander.
It is no surprise to any members active in this forum that Gloob has some strange ideas, and he has an annoying tendency to spout his own opinions as if they are fact. Well, I formulated a pretty interesting and comprehensive "treatise" on what is the perfect size for an expander, the other day. And with what I came up with, you will may need an oversize plug, and you may not. That is nothing new, you say. But maybe there's more to it. Anyhow, I came up with some of the details in response to a query/challenge I received, after I had spouted off a bit concerning my ideas on another forum. And here is my response, mildly edited:
************************************************** ***************************************
http://images.thehighroad.org/statusicon/post_old.gif Yesterday,
11:16 PM
#32 (http://castboolits.gunloads.com/showpost.php?p=9921022&postcount=32)
GLOOB (http://castboolits.gunloads.com/member.php?u=53020)
Member
Join Date: September 16, 2007
Posts: 5,675
In my estimation, which is worth
at least twice what you are paying for it, I figure a proper 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. So basically, the expander should be about the
same size as the bullet.
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 a tight sizing die.
If your sizing die is a little loose, already, then these dimensions will be too big!
But no worry, because in this case, you do not need an expander, to begin with!
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 should 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. A two mil under expander
is either acting as a perfectly good flare-only die or an inadequate expander.
If you wanted to make the perfect mouth flare die for a caliber, which will never
reduce neck tension, and which will at least make a small improvement on a grossly
tight case then 2 mils under is, indeed, the ticket and there is a technically sound
reason that this size is the default. It's because most of the time (for the average die)
it is only flaring the mouth, anyway, and it needs to be 2 mils under to not ever interfere
with neck tension. But if your sizing die is tight, you will do worlds better by using an
expander the same size as the bullet. So if you need to make the jump up, you ought to
make it all the way. There's no point in getting somewhere between the two. If your die is
tight, a -1 or -2 mil expander won't give you any more neck tension than a -0 expander, but it
will have a much greater ability to swage bullets.
http://images.thehighroad.org/smilies/evil.gifhttp://images.thehighroad.org/smilies/cool.gifhttp://images.thehighroad.org/smilies/evil.gif
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. In fact, using a full bullet diameter expander with a
tight size die will give more neck tension than ammo made with a "good" sizer
that doesn't require more than a -2 mil expander.