Reloading Procedures

There are often many chores in reloading that seem just that, a chore, but they form part of a necessary and key factor in building that all-important accurate load.

One of the most important parts of any reloaders kit has to be the case trimming tool, as this ensures that all your cases remain at a safe and optimum length. After all, the case is the only component that we keep and as such needs particular attention so that we can keep an eye on quality and eradicate dodgy cases. Being the launch pad from which the bullet is accelerated, a proper fitting, consistent, uniform and concentric case, will give that bullet the best start up the rifling of the barrel. Therefore, the careful preparation of the front and rear of your cases matter a lot in the reloading procedure. Pay attention to these two areas as much as you would the bullet and powder choice and you won’t regret it.

Trim it

All cartridges have a trim to length specification and this info is readily available in reloading manuals. Having a case that is trimmed to the correct length is very important as it ensures correct fitment into the rifle’s chamber. This not only maximises accuracy potential with correct bullet release but it’s essential for safe operating pressures. All cases move and stretch when fired in the chamber to differing extents but if you ignore the lengthening or migration of brass to the neck area, it can be dangerous.

If your cases become too long, then when loaded into the rifle, the end of the neck can crimp over or crush the bullet’s copper jacket and therefore fail to release the bullet correctly. This can dramatically increase the pressure to dangerous levels and if not that severe, it will affect accuracy. Measuring the length is easy with calipers but there are several ways to trim to length.

Trim tools

Trimmers are available from RCBS, Redding, Lyman, Forster Lee or Hornady. They work by either using a multi-stepped collet or shell holder that supports the case head, whilst at the other end a specific calibre pilot supports the case mouth and ensures it is square to the cutter blades. Most are manually handcranked and I prefer these as you can feel the brass coming off and any problems are translated directly through the hands.

Electric tool stations are good for high volume case length reduction and especially good is the range of micrometer attachments and differing cutting heads for specific calibres, as well as inside neck deburring tools of varying degrees to suit all types of bullet styles. Power attachments for hand drills are also available.

The Hornady Cam-Lock is a desk mounted trimmer and has a cast alloy base with twin operating towers at each end. One holds the Cam-Lock system and the other side is the rotating cutter. The system comes with a single cutter head that allows a precise cut of onethousandth of an inch at a time if necessary. This head diameter is suited for bullets from .22 to .50 calibre. The cutter has a central hole so the trim pilot can be fitted inside, so the neck of the case is supported throughout the trim process. The tool can be used by hand or a Power Trim adapter can be fitted as an accessory.

I regularly use a Wilson trimmer that holds the case in a tapered case holder that squarely lines up the case against the cutter, whilst an adjustable backstop varies the cutting depth. The cartridge case-specific holder is clamped down in twin rails and provides very accurate and square cutting. Slow yes, but still one of the most accurate.

Deburr/Chamfer

Once at the correct length you can start to fine-tune the ends. Most new cases will have a slightly sharp or burred edge to the mouth after the manufacturing process and the solution is to use a deburring tool. They are available from Wilsons, Redding, Hornady and Lee, to name a few, and some are reversible. This means one end can deburr and the other can chamfer. They look like a simple tool but consistency is the key word here. The aim is to achieve a smooth, even finish so that the bullet is released from the neck evenly. Think of it as the Saturn rocket on take-off, you want it dead straight and not yawing a little and hitting the gantry, or in our case the rifling, at a skewed angle. How many times have you pulled a bullet and seen nasty striated marks on the base where the case mouth / neck has worn away the copper jacket!?

Just insert the cone of the tool into the case neck and rotate three turns in a clockwise motion with a little applied pressure. That has chamfered the inside of the case neck. Reverse the tool and allow the cutters, three spurs on the Wilson model, to gently deburr the outside edge of the case, again about three turns with light pressure. I do the same for all my cases, although nickel plated ones tend to chatter more so take care.

Cutter angles are also key as most have a 45° angle for most styles of bullet bases and calibres from .17 to .45. However, the 28-30° VLD type cutters allow a shallower angle so that VLD or boat tail-based bullets seat easier without shaving off the copper jacket.

Necking

Neck wall thickness can indicate the uniformity of the whole of the cases wall thickness. If you think about it, any extreme variation to neck thickness can result in poor alignment in the rifle’s chamber and as the round is fired, the cartridge expands differently to seal the chamber and results in pressure and velocity differences. Any neck wall thickness that has a variation of 0.0015” or more should start the alarm bells ringing, as should any case that has a 0.0015” variation to its outside circumference. Special ball micrometers or wall thickness gauges from RCBS, Sinclair, Neco or Redding are available to measure this.

In regards to case weight, it’s worth mentioning that a variation in weight of between 1 and 2% is OK, which means with a .308 case, if the variation between cases does not exceed 2 to 4-grains, then that is acceptable.

It’s all in the detail

So, the primer pocket and flash hole. Well, European brass such as Lapua and Norma is more consistent from lot to lot because the case heads are machined and the flash holes are drilled, rather than punched. Any variation in the primer pocket dimensions and flash hole size can influence the smooth ignition of the powder column. During manufacture, burrs can form on the inside edges of the primer hole as it is drilled or punched through. These can interfere with the ignition process and one sign of this on target is a vertical dispersion of the group size, due to variance in velocity. It’s an easy task to remove such burrs with the correct tool and whether you can visually see the burrs or not, it is best to deburr and uniform all the brass the same. I use Wilson and K&M tools, but Sinclair, Redding, RCBS, Lyman, Dewey and Hornady all offer excellent tools. Some come as part of a tool station like the RCBS Brass Boss case prep centre.

Next is the primer pocket itself. Keeping the edges uniform to ensure a correct fitting primer is important, as is depth to ensure repeatability of firing pin strikes for each shot. Sinclair state that most firing pins protrude within a range of 0.045 to 0.060” and that with a primer seating variance of only 0.010”, the firing pin strike can vary as much as 20%. I use a Sinclair primer pocket uniformer in a small or large configuration, depending on the primer pocket size I need to uniform.

Conclusion

Most of these tools are simple hand devices that are not expensive but are time-consuming to use. However, it’s really important to fettle the necks and bases of all your cases if you want the best accuracy possible.

Contacts:

Norman clark - Reloading Kit - www.normanclarkgunsmith.com
Edgar brothers - Hornady - shootingsports.edgarbrothers.com
Gmk ltd - RCBS - www.gmk.co.uk
Hannams - Reload Kit - www.hannamsreloading.com
Henry kranks – Lee - www.henrykrank.com