W
WHL
Guest
when you read the term seated hard into the lands, how many thou over the bullet jam would you set your seater
C
Chuck Bogardus
Guest
It doesn't matter - the jam will run it back in the case.
The fun you get into here is with neck tension. And remember - if it's hard enough to jam into the lands, it's hard enough to STAY in the lands if you have to pull the case out. Which means that the powder's probably gonna go everywhere.
The fun you get into here is with neck tension. And remember - if it's hard enough to jam into the lands, it's hard enough to STAY in the lands if you have to pull the case out. Which means that the powder's probably gonna go everywhere.
sbindy
Steve B
Neck Tension
I size my cases so that they have .001 neck tension, and with my bullet seated .005 into the lands, it goes into the case easily when chambered. If the neck tension is .003 however, it resists going into the case much more. The only thing I can see that hard seating will get you that soft seating wont, is galled bolt lugs.
I size my cases so that they have .001 neck tension, and with my bullet seated .005 into the lands, it goes into the case easily when chambered. If the neck tension is .003 however, it resists going into the case much more. The only thing I can see that hard seating will get you that soft seating wont, is galled bolt lugs.
Bob Kingsbury
New member
Wilber,its never been said better.
Subjective really applies here. Ihave been really amazed with the
descriptions I have heard about how people seat bullets.
comparing seating depths in newly chamber stubs and ones
cut off after 1200rds, but done withthe same reamer is interesting.
Ferris Pindell once told me that a bullet can be in the lands 7 thou
before it is ever marked.Experiments have shown this to be true.
As the lands become dulled by use and cleaning,it takes more
presure against the lands to get the same mark.this is not always
total throat advance,but the rounding that comes with wear.
Do this,after finding the seating depth that works. place a case
in a barrel stub. stand this up under a dial indicater(finger type
with low preasure) zero the dial on the head of the case. Now seat
a bullet and put it gently in the stub. slide it under the indicator
and the reading will be how far you are in the lands. Most
people are very surprised. when you seat a bullet progressively
deeper in the case untill the dial is just at the point where the
case head was when you zeroed it, the bullet will still be stuck in the
lands enough that you can pick the whole stub, case and all up
by just grasping the case.
Subjective really applies here. Ihave been really amazed with the
descriptions I have heard about how people seat bullets.
comparing seating depths in newly chamber stubs and ones
cut off after 1200rds, but done withthe same reamer is interesting.
Ferris Pindell once told me that a bullet can be in the lands 7 thou
before it is ever marked.Experiments have shown this to be true.
As the lands become dulled by use and cleaning,it takes more
presure against the lands to get the same mark.this is not always
total throat advance,but the rounding that comes with wear.
Do this,after finding the seating depth that works. place a case
in a barrel stub. stand this up under a dial indicater(finger type
with low preasure) zero the dial on the head of the case. Now seat
a bullet and put it gently in the stub. slide it under the indicator
and the reading will be how far you are in the lands. Most
people are very surprised. when you seat a bullet progressively
deeper in the case untill the dial is just at the point where the
case head was when you zeroed it, the bullet will still be stuck in the
lands enough that you can pick the whole stub, case and all up
by just grasping the case.
Boyd Allen
Active member
As a matter of personal definition, jam is the length that a bullet will be pushed back to, with the amount of neck tension actually being used. I find this length by seating a bullet, measuring the OAL (To the bullet tip is OK at this stage.) chambering the round (or dummy if not at the range, at the line) , and remeasuring the round to verify that the bullet was set back when the bolt was closed. Subtracting the second measurement from the first and adding the amount that I want to be "off of jam" tells me how much to lengthen the seater stem/cap assembly of my arbor type seater die. At that point I record the OAL of the stem and cap assembly along with how far off of jam that setting will seat that particular bullet in the barrel that I am using (also noted). It is this stem and cap length that I work with from that point on, and since the stem contacts bullets on their ogives, and the initial setup was done with one bullet, it is not necessary to use an attachment on my calipers to measure off of the ogive. If you were to look in my range notebook, you would see powder measure setting, seater stem and cap length, temp. and humidity, date, and any other things that I did differently for that load such as bushing size. Obviously barrel, powder (including lot) and bullet are recorded as well, along with comments about the apparent accuracy of the load. I have barrels from several different manufacturers. Even though they are chambered with the same reamer, and I shoot the same bullet with them all, each has a slightly different optimum seating depth, relative to jam, which is itself different for each.