Precision Ballistics Swaging, How 6mm (.243) Precision Custom Benchrest Bullets Are Made

Swaging Process Details:

Overview: Bullets are manufactured in various ways. My custom bullets are hand-swaged. Bullet swaging is a method of using extremely high pressure (approaching 80,000 PSI) at room temperature to force a lead core into a copper jacket to form a bullet. Unlike casting, no heat or molten metal is used. The high pressure is applied with special, powerful presses, each designed to hold a precision, diamond-lapped, carbide die. I dedicate a separate press to each of the seven dies needed to make bullets to assure that there are no variances due to switching dies on a press.

First die squirts cores which makes the lead cores to exact size and weight for both flat base and boat tail bullets.
Second die seats the lead core into the copper jacket. I use one die for flat base, another die for boat tail bullets, or a third die for VLD (very low drag) bullets.
Third die points up the bullet with a 6/9 double radius ogive (15 ogive for VLDs) and forming the open tip meplat. I use one die for flat base, another die for boat tail bullets, or another die for VLD bullets.
Fourth die used for my Target VLD bullets, to close the meplat to a very high ballistic coefficient point with my custom Hoover tipping die.

My bullets are currently offered in 6mm, with a 6/9 double radius ogive, and have a 0.064" open tip meplat, in either a flat base, or a 0.062" by 14 degree, slightly rebated, boat tail base. New for 2010 are my VLD (very low drag) bullets in 90gr, 95gr, 103gr, 105gr and 108gr. My Target VLDs have a 15 ogive, a closed point, and a long 10 degree by 0.0175" boat tail, which is slightly rebated. My Hunting VLDs are the same bullets as the Target VLDs but they have not gone through the extra step of closing up the meplat, therefore the meplat is open and is 0.056". These are made to expand on fur targets.

Flat bases have slightly more surface area for the combusted gases to push against and are generally considered most accurate at shorter ranges, such as 100-200 yards. Boat tail bases are more aerodynamic and have a slightly higher ballistic coefficient (BC) than flat bases. Bryan Litz wrote in his book, Applied Ballistics For Long Range Shooting, "In word, the ballistic coefficient is a measure of how well a bullet penetrates the air. The attributes of a bullet that will determine how well it penetrates the air are: weight, cross-sectional area, and form factor." Boat tails have slightly less bearing surface and less dynamic core pressure which provides less friction and keeps the jackets a little cooler. This increases their velocity from flat base bullets of the same weight and they are more stable for longer distance shooting, such as 300 plus yards because they have a lower drag coefficient and produce less air turbulence. Bryan Litz defines drag coefficient in his book, as "a dimensionless quantity that has to do with how much drag the bullet will have at a given speed. More streamlined shapes have lower drag coefficients and at supersonic speeds, the drag coefficient changes a lot with velocity." Bryan Litz states that boat tails are less precise than flat base bullets because by adding the boat tail there is potential for imperfections like making the boat tail off center. Also, boat tails are more susceptible to muzzle blast and may cause the bullet to pitch and yaw, and they require a higher twist rate to stabilize. In his book, he summarizes, "The reason why we use boat-tails is because at extended ranges, the aerodynamic benefits overcome atmospheric variations better than flat bases, and make up for the marginally compromised precision potential." As a bullet loses velocity, base drag becomes more prominent in overall drag, thus boat tails, which have less base drag, work better at longer distances since the velocity drops the further out you shoot. This function is not as significant when shooting under 300 yards, so flat base bullets are theoretically better for shorter ranges.

I find that my customers and I are experiencing extremely good accuracy and precision with both my flat base and boat tail bullets out to 600 yards, and my VLDs excel particularly well at all ranges from 100 yards to 1000 yards! I close their 0.056" meplat to a point with a third pointing die, custom made for my VLDs by John Hoover, to increase their ballistic coefficient. Because both my standard 0.062" boat tails and my 0.175" VLD boat tails are slightly rebated, they combine the best features of both a flat base and a traditional boat tail base. Adding the rebate provides a more consistent and precise base like a flat base, making them inherently more accurate than a standard boat tail. Because they are also a boat tail, they offer the benefits of a boat tail and so a rebated boat tail is sort of a hybrid between the two designs. As the bullet leaves the muzzle, it is in a transitional state, no longer inside the bore, but still being propelled and effected by the escaping gases. This is where the yaw and the helical path is introduced, and a rebated boat tail allows a quick release of the gas and is directed more away from the bullet which has a smaller effect than a standard boat tail, theoretically making the rebated boat tail more accurate (published claims are up to 15% more accurate), and regarded as superior, to both flat or regular boat tail bullets. They reportedly gain up to 10% in muzzle velocity, while being easier on barrels.

The open tip design has long been revered for it's accuracy. It is designed for precision shooting, rather than to expand upon impact like a hollow point design. A jacketed hollow point bullet has a fairly large hole specifically added to the tip, whereas an open tip bullet gets it's small open tip as a result of forming the jacket into a bullet in the point up die. An open tip design has an extremely small aperture compared with a hollow point design. The open tip lightens the forward section of the bullet, shifting the center of gravity towards the back of the bullet. This produces an improved ballistic coefficient, greater down-range velocity retention, and greater resistance to crosswind deflection.

The common abbreviation for "grain" is gr., but highly sensitive scales use gn. as the abbreviation for "grain" to avoid confusion with grams. I have chosen to use gr. rather than gn. because it is most used, but both abbreviations mean the same thing. I make both my flat base and boat tail precision custom 6mm benchrest bullets 66 grains, (gr./gn.), as well as 68 grains, but can make them for your needs anywhere between 66 grains and 108 grains. I am expanding this to include 90gr, 95gr, 103gr, 105gr and 108gr in VLD design this year, as well as 88gr, 90gr and 95gr LBT (Long Boat Tail). Each one is made with J4 copper jackets, long known as the very finest jackets available with the closest tolerances in the jacket walls, consistently within 0.0003". My lead cores are squirted, cleaned and degreased with the best solution available, so the product you receive is as precise as I can provide it.

My bullets prefer to be jammed into the lands around 0.010" in my 6mmBR 1:14" twist barrel, but prefer to be jumped 0.010" in my 1:8" twist barrel. My 103gr, 105gr and 108gr VLDs prefer to be jammed 0.005" in my 1:8" twist Savage. My initial testing of my VLDs, without much experimentation is that they shoot five shot groups of 13/16" at 400 yards. Fine-tuning them should be fun! Because the bullet weight, bearing surface, ogive, case neck sizing, etc. likely differ from what you currently shoot, you must precisely measure your rifle's head space and experiment with your seating depth to find the exact total over-all length your rifle shoots best with, as well as experiment with the neck size of your brass to effect the internal pressure. Don't expect bugholes right out of the box until after you've done your experimenting with the variables.

Offering you the option of having me uniform the bullet's meplats and countersink them for you, forming them to the frequently winning 6/9 double radius or 15 ogive, and offering them with either flat, slightly rebated boat tail, or slightly rebated VLD base, and putting a proprietary closed tip on my Target VLDs, sets Precision Ballistics LLC apart from ALL other custom benchrest bullet manufacturers!

Here is a view of my shop, showing my six Redding presses.

First for boat tail seating
Second for 6/9 ogive point up
Third for flat base seating
Fourth for VLD and LBT seating
Fifth for VLD 15 ogive point up
Sixth for VLD tipping and my personal reloading

I believe in redundancy. I have at least two of everything needed to make my bullets to avoid down time when something breaks. My shop consists of six new Redding presses, five that have been converted to swage presses, mounted at 20 degrees and one mounted vertically. These allow me to dedicate specific dies to presses. Station one is to seat cores in my boat tail bullets. Station two is to point up my 6/9 ogive bullets. Station three is to seat cores in my flat base bullets. Station four is to seat my VLD and LBT bullets. Station five is to point up my VLD 15 ogive bullets and squirt my cores. Station six is to close the meplats of my Target VLD bullets with my custom Hoover tipping die and to reload my different bullets for research and development purposes (grin), or to compete at matches with my products or just shoot for fun. You can see my own blend of swage lube sitting on my bench. My two tumblers to lube my jackets are next to my two ultrasonic cleaners. Using my jeweler's scales, I weigh out exactly, to the hundredth of a grain, the same amount of my swage lube (2.5gr/1000) to apply to jackets in my two tumblers. Each jacket receives the same amount of lube (0.0025gr) to assure proper function in my carbide dies and proper finished length of each bullet. My core cutter is mounted below my center bench on a heavy block of wood, and the spools of lead wire are on the steel rod to it's left. There is a magnetic box to catch components or finished products and tally counters to validate each throw of the levers.

Precision Ballistics LLC shop.

Supplies and inventory for Precision Ballistics LLC:

Dessicants, Axarel 2200 solvent (I now use Lenium GS), shipping cartons, finished boxes of bullets, lubed jackets, lead cores, unopened J4 jackets, my rifles and shooting equipment, cartons of empty bullet boxes, and my EZ Up tent for selling bullets at shooting matches.

Precision Jackets: J4 jackets have a Total Indicated Run out (TIR) less than 0.0003". They possess the uniform wall thickness vital to accuracy due to a state-of-the-art computerized manufacturing process. Concentricity and weight are controlled per lot and all jackets are run through the same set of renowned Detsch carbide dies to ensure complete consistency. J4 has been defining and refining precision jackets for 40 years now with a reputation - and results - that are second to none. Precision Ballistics LLC is dedicated to that same standard, and uses only the finest materials in our manufacturing process. All customer orders are made up from the same jacket lots.

Precision Cores, Swage Lube, Degreasing Process: Each core is cut with a high heat-treated core cutter and swaged through a precision squirt die to be the exact weight needed for the bullets I am manufacturing. I run each bullet through the same set of renowned Detsch carbide precision swaging dies for consistency. I blend my own premium swage lube, of four parts 100% pure anhydrous lanolin and one part 100% pure neatsfoot oil. It is used to lube cut cores before squirting them, as well as the J4 jackets before they are loaded, seated and pointed up. It is completely removed from the squirted cores before they go into the jackets, and from the finished bullets ultrasonically at 60kHz with Lenium GS, which is heated to 160 degrees (it's boiling point) in my two ultrasonic cleaners. I used to use Axarel 2200, but Lenium GS works better, evaporates faster and is safer to use. Lenium GS is a high performance cleaning agent which is stabilized n-propyl bromide, that is safe and environmentally healthy. It is non-corrosive, non-carcenogenic and is ozone-safe. Lenium GS is approved for the aerospace and airline industry. This is the choice of NASA and the entire jet industry to clean their metal parts and printed circuit boards. It is the degreaser/defluxer used throughout the electronics industry. It leaves no residue, as do many other degreasers used in the custom bullet industry, which allows a perfect bond between the lead core and the copper jacket during the seating process. It removes all of the swage lube and turns the dull finish of both the copper jackets and the lead cores into a shiny jeweled finish. Lenium GS is one of the most expensive degreasers I could use, but it is worth it to make the best bullets for serious competitors.

Precision Core Squirting, Core Seating and Pointing Up: Each bullet I make goes through the same set of renowned Detsch carbide precision swaging dies, custom crafted to my exacting specifications, mounted in five Detsch-converted, Redding presses that swage each bullet under approximately 80,000 PSI pressure. Each die has it's own dedicated press so there are no minute changes from interchanging dies in just one press. There is a press for the squirt die to form the lead cores, one for the flat base seating die, one for the flat base point-up die, one for the boat tail seating die, and one for the boat tail point-up die. These presses are made to extremely tight tolerances, which removes all "lever-wiggle" as they are put through their cycles and allow for the proper amount of pressure required to swage bullets. They have been "trued" so each ram cycle is the same and is concentric with the centerline of the press. Using the same set of dies in dedicated presses for each bullet assures the great consistency that is required to manufacture precision benchrest bullets. I use a jeweler's scales that weighs to 0.01gr. when setting my squirt die to get the setting as close as I can make it. Each lead core is manufactured (cut and squirted) identically and is seated in identical J4 jackets, (each customer order comes from the same lot of J4s and that lot number is on the bullet box label), under identical conditions, and each bullet is pointed up identically. Further, at your option, each meplat will be uniformed and counter sunk identically by hand (three turns each for both processes). I manufacture my bullets with either a flat base having a 0.243" pressure ring, with a short boat tail base, with a 6/9 double radius ogive. The short boat tail starts distally from the base 0.062" and cuts back toward the base at 14 degrees, which provides outstanding flight stability. Then going up past the bearing surface, the first radius is the 9 tangential ogive, which is blended into the 6 tangential ogive near the tip, that continues to the 0.064" open tip meplat. My LBT (Long Boat Tail bullets have a 0.175: by 10 degree boat tail and is used on my bullets built with the 1.050" and longer J4 jackets. The word ogive is from the French for a curve, and is pronounced "OH-jive". I wear powder-free nitrile medical gloves during every process in building your bullets, to ensure that zero dirt or corrosion-causing contaminants every touch them.

Cutting and Squirting the Cores:

A 50# spool of lead wire, going into my core cutter, where cut wire cores fall into the bucket.

A cut lead wire core, ready to go up into the squirt die.

I cut my lead wire 3gr. heavier than the squirted cores need to be to assure consistency in each finished core. For example: 0.790" J4 jackets average 22.1gr., so the finished core needs to be 43.9gr to make a bullet 66.0gr. That means the cut lead wire for 66gr. bullets needs to average 46.9gr.

A couple of freshly squirted cores along with the extra lead that squirts out of the die. The lead is extrude through three 0.032" holes in the die and breaks into small pieces as it falls into the box under the die. You want 2.9 to 3.1 grains of extruded lead to squirt out to assure that the finished core is the correct weight. For a perfect bond with the copper, each core is degreased with Axarel 2200 prior to being inserted into a J4 jacket. .

Weighing the cores:

I use my RCBS electronic scale when I gross-weigh components to a tenth (0.1gn.) of a grain, and I fine-weigh components to the hundredth (0.01gn.) of a grain on my jeweler's electronic scale when I really need the exact weight for weighing swage lube and setting my dies. I also use stainless steel medical forceps with polyethylene covered tips, to prevent putting any marks on the bullets.

Loading and Seating the J4 Jackets:

A tray of J4 jackets ready to accept their lead cores.

A tray full of J4 jackets with a lead core above each one. When I pull out the plexiglass sheet between these two trays the lead falls down into each jacket.

A tray of loaded jackets ready to be seated as either flat base or boat tail base, depending on which die and press I choose to use.

A jacket loaded with a core, mounted on the punch, ready to go

into the flat base seating die. The boat tails are formed the same but I

use a different die with the boat tail shape inside the die.

The same jacket coming out of the die just before it falls into the magnetic box. Note the jackets in the box showing the lead compressed under approximately 80,000 psi.

A tray of seated jackets ready to be pointed up.

Pointing up the bullets:

A flat base, seated jacket going into the point up die. Notice the two finished 66 grain bullets already in the magnetic box below it.

The same seated jacket, which has had it's ogive formed in this die, and just before it falls into the box as a finished flat base bullet.

After I point up my bullets, I check them with a Sinclair quick bullet sorting tool to assure that the base to ogive dimension is the same from bullet to bullet. I set my tolerance indicators for + .001". If I start seeing finished bullets falling out of specs., I'll know to check for wear in the links and pins of my presses, and exchange worn parts with factory new parts.

From here, my bullets go to my ultrasonic cleaners to get a jewelry shine and degreasing, then on to my Quality Control area, get weighed, measured, counted, boxed with foam sheets and a dessicant, labeled and stored to be shipped. At that point, whether you are aiming at the X in the 10 ring of a benchrest target, or the eyeball of a prairie dog out in the distance, you can be assured of the most accuracy and consistent precision from one shot to the next possible!

I have 6mm J4 jackets in 0.790", 0.825", 0.900", 1.050", 1.150" and 1.290". My dies allow me to be able to build 6mm bullets, with a 6/9 double radius ogive, in any weight, from 66 grains through 108 grains, with either a flat base, my short boat tail base, my long boat tail base or my long VLD boat tail base. I am adding 14 designs for 2010, including my 85gr BT, my 88gr LBT, 90gr LBT and 95gr LBT, and my 90gr, 95gr, 103gr, 105gr and 108gr in Hunting and Target VLD designs in 2010. That makes 28 different bullet designs! I am currently building bullets in 66gr, 68gr, 74gr, 80gr, 85gr, 88gr, 90gr, 95gr, 103gr, 105gr and 108gr.

Finishing Process Details:

Precision Meplat Uniforming: The meplat of a bullet is the flat tip, where the jacket is drawn to a point. In a typical match bullet, this is the open tip. Uniformed meplats are very important because even small inconsistencies at the bullet's tip have a direct effect on the Ballistic Coefficient (BC) of the bullet. This is of particular concern for long range shooters, and at Precision Ballistics LLC, I offer you the option of me adding this process to your bullets, no matter what weight bullets you buy. While you will see improvement in your groups in direct proportion to the distance you shoot, you will see improvement at all ranges starting around 200 yards. Where velocity begins to drop off, differences in BC show up on the target as increased vertical spread. By definition, bullets with different BCs will drop at different rates. By trimming the meplats, bullet lengths are made more exact. In turn, the bullet-to-bullet variance in BC is dramatically reduced.

The end result is that you get a set of bullets that all arrive at their POC (point of contact) with the same elevation. I use the Montour County Rifles Meplat Uniforming Tool to do this option. It equalizes the BC of Precision Ballistic's bullets. The MCRifles tool is unique among other meplat uniformers because it does not use a Delrin insert to hold the bullet. Instead it features a caliber-specific seat for the bullet's ogive, precisely milled in the stainless tool body. The hole's diameter is milled specifically for only 6mm; accordingly it achieves a very precise fit. One of the drawbacks of other tools that employ a Delrin (plastic) insert is inconsistent bullet seating pressure arising from the natural "give" of plastic verses stainless steel. Because stainless steel is harder than copper, it sometimes puts a minor mark on the shaft, but this does not effect accuracy.

When you order meplat uniforming, I remove 0.002" from the tip, which pushes small burrs inside of the hollow point. I then use the center de-burring tool to remove these burrs and an even countersink is left in their place. This removes any inconsistencies in your bullet’s meplat, which produces better results, particularly at longer ranges. I get tighter groups at 200, 300, 400 and 500 yards with meplats I have uniformed and countersunk, than those I haven't done! The greater the distance the more you'll appreciate my meplat process!

You can see the bullet on the left has not had the meplat uniformed, the bullet in the middle has been uniformed only, and the bullet on the right has had the meplat uniformed and countersunk.

By uniforming the meplat the BC of the bullet is reduced by about 1%, which is equivalent to 1/8 minute of angle sight adjustment. Countersinking the uniformed meplats adds back some of the lost BC so the finished product has practically the original BC, and the POI of each group is on nearly the identical elevation, leaving the shooter to be mostly concerned with just windage.

By doing these extra final steps, I make your bullets more consistent projectiles, thus creating smaller groups. The BC is determined by multiplying a coefficient called the "Ingall's number", which represents the inverse drag of the air upon the bullet, times the mass divided by the square of the diameter. A high BC is sometimes thought to be necessary for one hole groups. An extremely high ballistic coefficient is not really as important as using the lowest practical spin rate, and reading mirage and wind flags. Doing these extra final two steps eliminates one more variable in extreme accuracy reloading. This tool is currently being used by some of the top shooters around the world in 1,000 yard bench-rest, high power, F-class, long-range hunters and many other facets of shooting.

If you are serious about minimizing your groups, and want more consistent shot to shot accuracy, especially at extended ranges, you simply cannot afford to shoot bullets that have not been uniformed and countersunk with this process. At Precision Ballistics, I offer these extra steps to you to ensure that every precision custom benchrest bullet in your box is nearly identical.

Target VLD Point Tipping: I use a Hoover bullet tipping die, custom made for my Target VLD bullets, to increase ballistic coefficient (BC) and to make them more consistent. That is the only difference between my Target VLDs and my Hunting VLDs, where hunters want the meplat to open up inside fur targets.

My Hoover Tipping Die

Here is my set up for tipping my VLD bullets.

One of my Hunting VLDs ready to go into my tipping die.

One of my 105gr Target VLDs coming out of the tipping die.

The regular Bullet Pusher that comes with the Hoover Tipping die is for an RCBS press. They had CTK Precision custom make me one that fit my Redding Big Boss II press much better.

The bullets in the first two columns have been tipped and are now Target VLDs, while the rest of the bullets are Hunting VLDs ready to be tipped up to become Target VLDs.

The pressure ring on my VLDs is 0.2435", whereas on my smaller bullets it is 0.243".

Dessicant/Foam: Each box of bullets from Precision Ballistics are shipped with a dessicant inside to absorb any residual or atmospheric moisture in order to reduce any risk of discoloration of the copper. I place sheets of foam on the bottom and top of the box to prevent the bullets from bumping each other in shipping. That prevents any damage to the bullets and prevents rattles. Each box is secured with packaging tape to prevent any boxes from accidentally opening during shipping as well.

Quality Control: During my quality control, I measure my bullets to the half thousanth of an inch, and weigh them to the tenth of a grain. I make all bullets of the same weight and style as identical as possible. I place the caliber, weight, ogive, style, quantity, J4 length and lot number on every box label.

My preventive maintenance schedules keep every press and die within factory-new specifications to assure my finished bullets are very uniform.

Preventive maintenance schedule for my presses: Every three months I disassemble each press, inspect and measure with a micrometer for any wear, clean, lubricate with 14% molybdenum grease, and replace any worn parts with brand new parts from Redding.

Preventive maintenance schedule for my dies: Every month I disassemble each die, inspect and measure with a micrometer for any wear, clean, lubricate with 14% molybdenum grease, and replace any worn parts with brand new parts from Detsch Custom Bullet dies.

Welcome to Precision Ballistics LLC!

Serious benchrest bullets for serious competitors !!!!