Drive band bullets are different from standard bullets and easier to reload.
 
Follow the procedure below, it is easier but it differs from the procedure you would follow with other monometal bullets or jacketed lead bullets. 
 
Please read all of it to save you time and money.
 

This data only applies to GS Custom HV, FN, SP and HG bullets with drive bands. Load data does not apply to bullets with grooves on the shaft or bullets with smooth shafts, dangerous pressures may be generated. Click here to see the difference.

For load guidelines with old style GSC HP Bullets without drive bands, click here

Procedure:

Drive band bullets are different from standard bullets and easier to reload. 

If you follow the procedure below, you should complete your load development for speed and accuracy in the minimum of shots.  If you need to fire more than 21 shots, something is wrong and you are welcome to contact GSC so that we can help.

NOTES

  • Always use a magnum primer with drive band bullets.  See the reason.

  • Do not crimp drive band bullets.  See the reason.

  • Prepare cases properly. Do not expect good results with bad preparation. See our loading tips.

  • Start-loads may produce maximum speed in some rifles. The start loads in our tables are safe loads in our experience but not minimum loads.  Start loads can be reduced, if required. Develop loads with a chronograph.

  • Develop speed first by loading one or two cartridges at the start load and one or two each increasing incrementally.  If your chronograph is reliable, one load at each charge increment is sufficient.  Increase the load with approximately 2% steps of the start load.  (Eg.: 10gr start load = steps of  0.2gr, 25gr start load = steps of 0.5, 50gr start load = steps of 1gr and 100gr start load = steps of 2gr)

  • The indicated maximum speed in the tables, after adjustment with the FPS/INCH number, will closely correspond to the maximum pressure allowed for that caliber. The indicated speed in the tables is the maximum speed, it is not the recommended speed.

  • In your rifle, the load that gives the maximum indicated speed is also the maximum powder load and it must not be exceeded. The indicated speed in the tables is the maximum speed, it is not the recommended speed.

  • The powder load required to reach the MAX FPS will differ from rifle to rifle and the suggested start load will give varying speeds in different rifles. The indicated speed in the tables is the maximum speed, it is not the recommended speed.

  • Do not try to adjust grouping by varying speed. Drive band bullets are relatively insensitive to tuning with speed. Groups are tuned by varying cartridge overall length (c.o.l.).   See the notes on cartridge overall length.

  • It is therefore best to separate the two processes and to develop speed first with no regard to what grouping is.

  • Using the start load, load the bullet with two drive bands into the case neck.

  • Check if this cartridge overall length (c.o.l.) will fit in the magazine box of the rifle.  If it does not, seat the bullet deeper until the cartridge fits the magazine. Never seat the bullet deeper than with the first drive band clear of the case neck.  See the reason for this.

  • Check if the c.o.l. will allow the cartridge to chamber. If it does, continue with speed load development.

  • HV and FN bullets do not cause pressure spikes when loaded touching the rifling. See the reason for this.

  • We recommend to load 50fps to 100fps from the maximum speed for general use.

  • Once the desired speed, on which you have decided is reached, load 15 rounds with that powder charge and at the maximum cartridge overall length (c.o.l.) possible in the rifle.

  • Fire three for group. Run a dry nylon brush through the barrel and allow it to cool while the group is measured. Seat the next three rounds 0.5mm (0.02") deeper and fire for group. Repeat the process until it is established what the ideal c.o.l. is for the rifle. Use 1.0mm (0.04") steps if the bullet is over 100 grains.

Troubleshooting:

  • The signs for pressure and the signs for excessive headspace caused in the loading process, are virtually identical. If headspace/pressure signs occur at substantially lower speeds than the maximum speed indicated, make sure a magnum primer is used. If headspace/pressure signs are still present at low speeds, check that the sizer die is correctly set, according to the procedure described at this link.
 
GENERAL

  • Should you need any information regarding load development and suitability for specific cartridges which are not to be found in the tables, or if your cartridge is not listed, please e-mail us.

  • Load Data is reviewed as components change and the tables are adjusted on an ongoing basis.

  • The load data tables represent data collected from internal ballistics software, pressure test data from certified laboratories and load data developed by us.  Start loads can be used in any rifle in good condition but the MAX FPS number must never be exceeded and must be approached as all maximum load data is approached - with caution and with checks for signs of pressure.

  • HV, FN and SP Drive Band Bullets allows the reloader to achieve higher speeds, weight for weight, than with lead core or grooved bullets, without exceeding maximum pressure levels.

  • External ballistics always improve with additional speed and, contrary to what is the case with lead core bullets, with HV and FN bullets, terminal ballistics always improve with additional speed.

  • The exception would be if you require only standard speeds and want to reduce recoil. HV, FN and SP bullets work at lower pressure levels and therefore reduce recoil at standard and lower speeds.

  • Internal ballistics are superior with HV, FN and SP bullets in all cases and two to three times the barrel life can be expected.

  • Use our HP Bullet range at normal speeds if you do not want the advantages that drive band bullet technology makes available to you.

  • Use an HV, FN and SP bullet that is recommended for the calibre and twist rate. See our Tech Data pages for assistance.

  • HV, FN and SP drive band bullets do not raise pressure levels like jacketed lead and standard and grooved monometal bullets do, when seated against the rifling.

For more information see the "FAQ" section.
 
Burn Rate Chart with more than 260 powders Load Development Chart Sighting In Target

Warning!!

Do not use HV, FN and SP drive band bullets load data for any other type of bullet, our HP range included. Dangerous pressures may be generated, leading to damage to the firearm and injury. See the HP Load Data for HP loads and consult the load guides of other manufacturers for data concerning their products.


GS Custom Bullets, situated in Port Elizabeth on the East Coast of South Africa, manufactures solid copper, turned, monolithic bullets for hunting and sport shooting. These bullets are used by hunters on several continents, hunting from the smallest of antelope to the largest of dangerous game, using the smooth HP bullet, as well as the more popular HV, FN and SP bullets with the patented drive band concept. GSC bullets are configured for the highest possible ballistic coefficients. SP bullets are mainly used for sport shooting. All GS Custom Bullets are coated.