Reloading Bacis: Making Substitutions

When we flare the mouth of a case to accommodate a bullet it is important to tailor the flare to suit the particular type of bullet being used. Jacketed, powder coated and plain lead-alloy bullets each need a different amount of flare on the case mouth and some heads need none. It is also important to consider that any flare put onto the case needs removing again, after the bullet is seated, and this whole process puts a lot of strain on the brass at the case mouth.

Bullet types

Jacketed bullets, used in most centre-fire rifle calibres, are tougher than other types and so can be seated into a case without easily being damaged. The copper jackets cover the entire surface in contact with the case and this allows the bullet to withstand the stresses and strains of the reloading process much better than plain lead projectiles. Bullets with a boat-tail profile are even easier to seat as the tapered section sits into the mouth of the case and helps start the bullets journey into the case during seating.

Powder coated bullets are becoming more popular for a couple of reasons. Firstly, the coating completely covers the lead bullet and so the risk of lead contamination, from airborne lead when the bullet leaves the barrel of the gun, is considerably reduced. Secondly, there is no need to lubricate powder coated bullets, so they are much cleaner and easier to handle. On the downside, the powder coating does increase the diameter of the finished bullets and it is also relatively easy to damage the coating during the seating process. Extra care, and extra case mouth expansion, is needed when seating this type of bullet to avoid damaging the coating.

Lead, and for that read leadalloy, bullets are generally used in most pistol calibre shooting and the hardness of the alloy varies according the type of gun they are used in. Being so much softer than jacketed bullets, lead projectiles also need care and consideration when seating them into the cases. With flat-based lead projectiles in particular it is very easy to damage the bullet as it is seated into the case if the flare is not right.

Flare to suit

With centre-fire rifle ammunition fully jacketed bullets are usually used and, once the bottlenecked case has been resized, the bullet is seated without any flare being applied to the case.

This ensures a good tight fit of the bullet and any crimp that is applied is to tighten the grip of the case on the bullet and smooth out any bulges. Jacketed bullets loaded into straight-walled cases do tend to require a little bit of flare, to ensure the bullets enter the case smoothly and sit straight and true. If there is no bevel on the base of the bullet it can be tricky to seat without expanding the case mouth, but it should be minimal, just enough to get the base of the bullet into the case mouth.

If you are using powdercoated bullets it is very easy to damage the coating during seating and so the flare on the case needs to be that bit wider and go deeper into the case. If you do not allow enough room to accommodate the coating then the case will literally scrape it off as you push the bullet in. With insufficient flare of the case you will find the powder coating from the bullet in the form of small curved shavings dropping out of the seating die.

Lead bullets vary considerably in hardness and, though they all require the case mouth expanding to some degree, some experimentation is needed to see just how much your particular bullets need. Softer lead bullets, particularly those without a bevelled based, are very easily damaged if the case mouth is not expanded enough and there are a couple of signs to watch for. If, after you have fully seated a bullet, there is lead on the outside of the case you have literally shaved it off with the edge of the case. In extreme cases both the bullet and the case will be ruined. Also, you may see a small bulge in the lead around the perimeter of the case mouth. This occurs where lead is pushed forward by the case mouth as the bullet is seated and then crimped.

Picking the right tools

Case expander dies use a neck expander plug which is pushed into the case mouth to open it up to receive a bullet. The size and shape of the plug varies from brand to brand and the resulting flare is also different depending on which one you are using.

Lee Precision three and four die sets include a ‘powder through expanding die’ which flares the case mouth using a plug with a straight sided forward section. This section of the plug travels into the case mouth giving a uniform and deeper expansion making it possible to create space for softer bullets, and those with a powder coating, to be seated further into the case without damage. The die is fully adjustable so less expansion can be applied for jacketed bullets where such damage is far less likely.

The Lee Universal Case expanding die uses two interchangeable plugs of different size and taper, depending on what calibre you are working with. The taper on the plugs is relatively steep and there is no flat sided section on the plug which enters the case. Expansion is therefore limited to the very front edge of the case mouth giving a flare like the front of a trumpet. This is ideal for seating tougher bullets which only require minimal flare to get the bullet into the case, for example jacketed bullets.

RCBS produce ‘Cowboy Reloading Dies’ which are intended for reloading straight walled cartridges for cowboy action shooting and specifically lead bullets. The expander plug included in these sets is much longer than those found in other dies and the very small increase in diameter further up the plug is almost undetectable. The expansion plug goes into the case the full seating depth of the bullet shank and the result is a very smooth and easy bullet seating. Loading fairly soft flat-base bullets in 45-70 calibre is extremely smooth with these dies, with no shaving of the bullet or bulges forward on the case mouth on finished ammunition. The results that have been achieved so far using these dies are very encouraging and a full review of them will follow in due course.

Conclusion

Case expansion is necessary to make it possible to seat many types of bullet, but it has a detrimental effect on the life expectancy of the cases due to the stresses it causes. The best approach is therefore to expand the cases as little as possible, to suit your particular bullets. Too little case-flare and you risk damaging your bullet and possibly the case too. Too much flare and you will rapidly over stress your brass and the case mouths will start to crack after only a few uses. In order to get it right you need to do a bit of experimenting with empty cases and gradually adjust the amount of expansion until you have just enough to accommodate your bullet. Starting with too much flare, and gradually reducing it until you can just start a bullet into the case mouth easily and seat it without damage, is more economical than starting with too little and destroying cases and heads during testing. The different types of dies available suit different types of bullet and is well worth investing in an expander die that best suits the bullets you are using in your reloading.

Contacts

Lee Precision reloading equipment; Henry Krank &Co. Ltd: henrykrank.com
RCBS Cowboy dies; GMK Ltd: gmk.co.uk