RELOADING GUIDELINE

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 us so that we can help.


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 in half grain increments. Use one grain increments if the bullet is over 100 grains.

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 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 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.

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.

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.

Once the desired speed is reached, load 15 rounds with that powder charge and at the maximum cartridge length possible in the rifle. We recommend to load 50fps to 100fps from the maximum speed for general use.

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.

* Important remark: "The faster you drive them, the better they perform."
However, don't exceed the manufacturer's maximum speed as indicated on Load Data sheet!

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WHY magnum primers & recommended propellant?

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  Black & white only.

Colour printers: Bright Orange Target.

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SOMCHEM POWDERS
Smokeless Propellant For Reloading

S 265     Slow burning extruded for small rifles & magnum revolvers
             ~ Single-base extruded.

S 321     Fast burning spherical for rifles ~ Double-base spherical.

S 335     Medium burning extruded for rifles ~ Single-base extruded.

S 341     Medium burning spherical for rifles ~ Double-base spherical.

S 355     Medium burning extruded for rifles ~ Single-base extruded.

S 365     Slow burning extruded for rifles ~ Single-base extruded.

S 361     Slow burning spherical for magnum rifles ~ Double-base spherical.

S 385     Slow burning extruded for magnum rifles ~ Single-base extruded.

Single-based powders ~    A single-based powder is one in which the only flammable ingredient is nitrocellulose.

Double-based powders ~    Both the solvent (nitro-glycerine) and the substance dissolved in it (nitrocellulose) burn when ignited producing a double effect.