Trimming the Meplat on
80 grain SMK Bullets
Is the Meplat
Trimming going to be
short lived fad with marginal benefits at best like Moly Coating
out to be, or is it actually going to have some seeable and tangible
for the long range shooter? Only time
will really tell. The little tip
variations you see on hollow point match bullets have always been some
to me. However my very limited
comparison of 180 grain ballistic tip bullets to a 180 grain MatchKings
years ago only proved to me that both hit the railroad rail holding the
500 meters with the same sight setting and same powder charge or
However, when Mr. David Tubb’s speaks I
listen. So his finding at the longer
range caught my attention. I have been
playing around at 600 yards for the past couple of years and I have
more vertical displacement then horizontal on most nights.
So may be the Meplat trim is something I
should try. After seeing pictures of the
Meplat trimmer online, I decided to give it a try.
I also happen to have one mill bite in my
tool collection and it also just happened to be 3/8 inches in diameter
should be just the ticket for
of some before and after
I do not have a lathe but do
have good collection of thin brass tubing.
My Meplat trimmer is made from a series of thin brass tubes
together. I started with a 3/8 inch
inside diameter piece of brass tubing which allowed the end mill fit
First the brass
tubing length was
determined. The tubing length allows the bullet boat tail to just stick
one end and be long enough for the
mill end cutter a shaft collar to control the depth of the cut.
one end of the brass tubing I
inserted several small pieces (about 3/4 inch long) of brass tubing
hold the 80 grain MatchKings. The
diameter of the small tubing pieces were decreased until the 223
would just fit.
the other end of the brass tube
I also added four small pieces of brass tubing 5/16 inch long in
diameter. This increased the area on the
one end for contacting the stop collar on the end mill bit. Some of the little shaft collars I found all
had a small chamber on the inside hole which required the larger area
diameter on one end of the brass tube for the collar to contact.
the small brass pieces were
soldered together except the one to hold the bullet. Since I do not
lathe or any chambering tools or reamers, however I still need a way to
the bullet inside the brass tubing. So
some epoxy to the rescue. With a little
release agent on the bullet I cast a pocket or chamber from an 80 grain
order to have the bullet
correctly centered and aligned within the brass tubing I wrapped the
portion of the bullets bearing surface with some scotch tape. About six layers of tape allowed the bullet
to just fit into the brass tube and centered base
of the bullet within the tube. I then
cast the front part of the chamber or pocket.
After the epoxy was cured I removed the bullet.
Then I removed the tape from the bullet. Next
I removed any release agent on the
bullet and inside the brass tube cast chamber.
Then reapplied release agent to the bullet and cast the rear
the pocket or chamber where to tape was in the brass tube.
When the bullet is placed into the trimming
holder, just the rear boat tail portion of the bullet is sticking out. The bullet is completely supported along the
bearing surface and part of the bullets nose.
A small portion of the bullets nose sticks out inside the
trimming the bullets Meplat and also allows pushing the bullet out of
pocket after trimming.
this cast chamber method requires
a little more effort; the bullet must be pushed in and out of the brass
tube. However this extra effort pays off
later, the bullet is held tight enough to prevent spinning during the
operation and also hold the bullet in the correct alignment while
the Meplat trim.
have incorporated my cordless
electric screwdriver into this trimming operation. This makes the
process go very quickly and easy. Just
press the bullet into the holder and stick the holder on the cutter. The bullet is held into the holder well
enough to prevent spinning while cutting.
Just a small amount of pressure is required on the end of the
while cutting. A small wooded stick
sticking out of a little wooded block
pushing the bullet out easy. Pushing the
bullet out while in the vertical position also allows for all of the
copper chips to fall out. I am currently
over trimming my 80 Sierra MatchKings. I
am removing about 0.037 inches from the nose of the bullet. The first trimmer I made the bullet chamber
was off centered thinking it would cut better and not rotate, wrong,
the end mill deformed the bullet a little to one side while cutting and
burr. Putting the bullet in the center
is crucial for a good cut. So after
trimming some wrong and trimming them again and may be again I am
0.037 of an inch being removed. They
seem to shoot okay so that is wear the stop is on the cutter for now.
so far seem to indicate
less vertical for me. It is hard for me
to quantify this more than saying I think so because I have been
things at the same. For now I am going
to keep doing it for the 600 yard space gun 80 Sierra MatchKing Ammo.
first holders I made were for
a 3/8 inch diameter end mill. However
the better choice is a 3/16 inch four fluted end mill with a 3/8 inch
shaft. Since I am going to keep this
trimming process going for awhile I noticed to remake the holder for
grain MatchKing bullet and document the procedure for this article. I had to dull the outside edges on the 3/8
end mill so it would not cut the inside of the brass tubing. The 3/16 diameter end mill would
be easier to get in and out of the 3/8 I.
D. brass tubing and will
affected by any of the copper chips. The rest of my current holders may be shorten
and used with the 3/16 inch diameter end mill.
Here is my
finished meplat trimmer and cutter. The easy way to do all this
is just order the Ballistic
Meplat Uniformer BMU from David Tubb.
Any Questions or
Web Page Comments
November 3, 2004
Revised - November 3, 2003