MtGun44
07-17-2010, 11:56 AM
The 9mm Parabellum (9mm Luger) is a bit of a problem child in reloading
with boolits. :twisted: There have been a lot of newbie questions, and
this leads to repeating the same old stuff, but in bits and pieces. I decided
to pull together my recommendations on how to most likely hit a good
load the first try. Not the only way, but a way that has worked for me in
a number of 9mms.
WITH JACKETED BULLETS the "standard bullet size" is about .355 or .356.
If you use this diameter in the great majority of 9mms with cast, you will get
boolits hitting the target sideways at 10 yds and often terrible leading. The
problem is that the groove diameter of the barrels run up to .357” or even
more and you need to have a boolit that is .001 or .002 inches LARGER
diameter than the groove diameter.
Measure groove diameter by “slugging the barrel” - remove from gun, drive
a soft lead slug thru the barrel with a brass rod and measure the largest
diameter WITH A MICROMETER not a caliper.
The typical caliper is rated to be accurate within plus or minus .001 inch. This
means if you measure a bore slug at .357, it could be .358 or just as well, it
could actually be .356. There is absolutely NO WAY to know between the limits
what the actual measurement is. Pretty useless for this application, really.
You need a micrometer which is accurate to .0001 inch, or TEN TIMES the accuracy
of a dial caliper. In answering a question on another thread I went out to
Enco, a large national supplier of precision tools and equipment for the machining
industry and found an amazing sale. It is amazing that you can get such a
precision device for under $35 delivered.
http://www.use-enco.com/CGI/INSRIT?PARTPG=INLMKD&PMPXNO=16720828&PMAKA=619-3106
This is a real decent tool for an amazingly low price. If you do not have a
micrometer, you should consider dropping the $35 or so (with shipping) that
this costs and start REALLY knowing what diameter that mold drops, or what
diameter that sizer die sizes too
Select a good boolit design. IMO, avoid the Lee tumble lube designs for 9mm.
They can work but 9mm is a bit of a PITA and using this marginal lube design
(which is easy and cheap to get started with, I admit) increases your probability
that you will fail and need to start over with a new mold and conventional lube.
Try the excellent Lee 356-120-TC (pn 90239 in 2 cav) or the Lee 358-105-SWC
(pn 90316 in 2 cav) and air cooled wheel wts, sizing to actual slugged (measured)
groove diameter +.001 or .002 inch diameter, use a standard lube like NRA formula
50-50. It is possible that you would have chambering difficulties with a .358 boolit
and a very tight chamber. If this happens, try different brand brass cases, some
are very thick in the neck and can cause this problem. Thinner case
necks may solve this problem.
If you do not have a lubrisizer, you can pan lube or hand lube. Use the search
function on this site to learn about these simple and cheap methods.
Get some approved loading data for your chosen powder. If you are starting
from scratch, Bullseye, Titegroup, Unique, Universal, HP38, W231 are all good
choices. Start at a starting load, slowly work up once you get things working.
Hodgdon has a great site:
http://data.hodgdon.com/cartridge_load.asp
It is best to have a separate taper crimp die, but careful use of a single stage seat
and crimp die can work it set up carefully. Remove the barrel and use the chamber
as a gauge to set the crimp and depth of seating. Look for the boolit to be
engraved by the rifling if seated too long, and the cartridge will not drop freely
into the chamber all the way flush with the end of the barrel hood. Keep increasing
seating depth until the boolit does not interfere with the rifling and seats fully with
no more than 1 lb force. IGNORE load book seating depths, seat to just clear your
rifling and so the cartridge drops all the way into the dismounted chamber.
Quick review:
- avoid Lee tumble lube designs and LLA lubricant in this caliber
- fit the boolit to the barrel +.001 or .002 over groove diam (slug the barrel)
- use a conventional lube groove boolit design and known-good lube like NRA 50-50
- use air cooled wheel weight alloy to start
- use barrel as seating depth setup tool - ignore book seating depths
- slight taper crimp is preferred, regular crimp can be OK, remove the flare plus a touch
- use a factory load data for similar bullet weight, exact match is not important
- use a starting load, then work up slowly
Enjoy. :drinks:
with boolits. :twisted: There have been a lot of newbie questions, and
this leads to repeating the same old stuff, but in bits and pieces. I decided
to pull together my recommendations on how to most likely hit a good
load the first try. Not the only way, but a way that has worked for me in
a number of 9mms.
WITH JACKETED BULLETS the "standard bullet size" is about .355 or .356.
If you use this diameter in the great majority of 9mms with cast, you will get
boolits hitting the target sideways at 10 yds and often terrible leading. The
problem is that the groove diameter of the barrels run up to .357” or even
more and you need to have a boolit that is .001 or .002 inches LARGER
diameter than the groove diameter.
Measure groove diameter by “slugging the barrel” - remove from gun, drive
a soft lead slug thru the barrel with a brass rod and measure the largest
diameter WITH A MICROMETER not a caliper.
The typical caliper is rated to be accurate within plus or minus .001 inch. This
means if you measure a bore slug at .357, it could be .358 or just as well, it
could actually be .356. There is absolutely NO WAY to know between the limits
what the actual measurement is. Pretty useless for this application, really.
You need a micrometer which is accurate to .0001 inch, or TEN TIMES the accuracy
of a dial caliper. In answering a question on another thread I went out to
Enco, a large national supplier of precision tools and equipment for the machining
industry and found an amazing sale. It is amazing that you can get such a
precision device for under $35 delivered.
http://www.use-enco.com/CGI/INSRIT?PARTPG=INLMKD&PMPXNO=16720828&PMAKA=619-3106
This is a real decent tool for an amazingly low price. If you do not have a
micrometer, you should consider dropping the $35 or so (with shipping) that
this costs and start REALLY knowing what diameter that mold drops, or what
diameter that sizer die sizes too
Select a good boolit design. IMO, avoid the Lee tumble lube designs for 9mm.
They can work but 9mm is a bit of a PITA and using this marginal lube design
(which is easy and cheap to get started with, I admit) increases your probability
that you will fail and need to start over with a new mold and conventional lube.
Try the excellent Lee 356-120-TC (pn 90239 in 2 cav) or the Lee 358-105-SWC
(pn 90316 in 2 cav) and air cooled wheel wts, sizing to actual slugged (measured)
groove diameter +.001 or .002 inch diameter, use a standard lube like NRA formula
50-50. It is possible that you would have chambering difficulties with a .358 boolit
and a very tight chamber. If this happens, try different brand brass cases, some
are very thick in the neck and can cause this problem. Thinner case
necks may solve this problem.
If you do not have a lubrisizer, you can pan lube or hand lube. Use the search
function on this site to learn about these simple and cheap methods.
Get some approved loading data for your chosen powder. If you are starting
from scratch, Bullseye, Titegroup, Unique, Universal, HP38, W231 are all good
choices. Start at a starting load, slowly work up once you get things working.
Hodgdon has a great site:
http://data.hodgdon.com/cartridge_load.asp
It is best to have a separate taper crimp die, but careful use of a single stage seat
and crimp die can work it set up carefully. Remove the barrel and use the chamber
as a gauge to set the crimp and depth of seating. Look for the boolit to be
engraved by the rifling if seated too long, and the cartridge will not drop freely
into the chamber all the way flush with the end of the barrel hood. Keep increasing
seating depth until the boolit does not interfere with the rifling and seats fully with
no more than 1 lb force. IGNORE load book seating depths, seat to just clear your
rifling and so the cartridge drops all the way into the dismounted chamber.
Quick review:
- avoid Lee tumble lube designs and LLA lubricant in this caliber
- fit the boolit to the barrel +.001 or .002 over groove diam (slug the barrel)
- use a conventional lube groove boolit design and known-good lube like NRA 50-50
- use air cooled wheel weight alloy to start
- use barrel as seating depth setup tool - ignore book seating depths
- slight taper crimp is preferred, regular crimp can be OK, remove the flare plus a touch
- use a factory load data for similar bullet weight, exact match is not important
- use a starting load, then work up slowly
Enjoy. :drinks: