BPCR Guide: Lubricants & Cases

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Written by: Dick Trenk

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The black powder bullet lubricant must do several things which are different from lubricant used in smokeless powder reloading.

Black powder leaves more fouling in the barrel and chamber than smokeless powder. One hundred years ago the better grade of powders left a moist fouling which did not affect repeated shots too much and allowed many shots to be fired before the barrel needed to be wiped out.

Current powders leave a hard dry fouling which will soon make it difficult to chamber another round and will also affect accuracy.

To combat this problem, special lubricants are available and the current thinking is that the lubricant must have NO petroleum products in it and will be made from all natural animal grease or vegetable materials and oils. Bees wax is also a common and major ingredient in successful black powder lubricants.

Several commercially made lubricants have proven effective and many shooters mix up their own lubricants which work quite well.

To keep the powder fouling soft, target shooters use a short length of tubing to blow into the chamber after each shot. Moisture in the breath is absorbed by the fouling and allows many shots to be fired before a wipe out with a dry patch is required.

Many advanced shooters have reported that they do not use the blow tube but wipe between each shot, thereby getting the very best repeatable accuracy. Wiping between each shot is not always possible so you will see most shooters using the blow tube routine.

Hunters usually have no need to blow moisture into the barrel since they rarely get more than one or two shots at an animal and therefore can wipe out the barrel properly after shooting.

In humid weather one or two breaths into the blow tube may prove to be enough to keep fouling wet and soft. On a dry hot day you might need 6-10 breaths to keep things soft inside the barrel.
Drink lots of water between blowing. This helps your breath to stay extra moist.

The actual blow tube can consist of a ctg. case which has the primer pocket drilled out to accommodate as large a plastic or rubber hose as possible.

Inserting the ctg. case into the chamber will prevent the moisture from your breath from wetting the chamber walls. We want to keep the chamber walls dry and just apply humidity to the barrel portion.


Because the 40-65 and 45-70, 90, 100, 110 and 120 case are almost straight, they should not require full length resizing at any time and once fire formed in your own gun there will be better accuracy obtained from such cases. If you intend to fire these cases in some other guns it may be smart to try your ammo in the other guns to see if they will fit properly. If necessary, you can full length resize the cases back to standard size and fire form them in the next gun.

Once fire formed, keep your cases carefully segregated so they will not be used in another gun.

Try new cases in your gun to assure they will chamber and full length resize only if necessary. This general advice applies to any other BP case which is almost a straight wall design. Cases which have a bottle-neck (BN) shape present different reloading problems and will usually require at least neck resizing for each reloading. The BN cases are sometimes more difficult to obtain good accuracy from and beginners are advised to start with the straight wall cases mentioned in this text.

Dies made to handle the common 45-70 caliber will work OK for the 45-90, 100,110, and 120 neck sizing operation and bullet seating operation. Just set the die so the case is inserted only enough to rework the neck area and not to resize the full length of the case body.

Somewhat better case control and possibly a bit more resizing accuracy can be obtained when using the correct die for each caliber ctg. But the 45-70 die will usually produce ammunition of excellent accuracy when it is used for those longer cases.

Since full length resizing is not normally required when cases are fired only in one rifle they will go back into that rifle without problems.

The 45-70 full length sizing die can be adjusted to perform the required “neck sizing” on the longer 45 cal. cases right up to the 45-120. The expander ball will do its job as well using the same procedures.

The 45-70 bullet seating die also can be adjusted to seat the bullet (and apply a crimp if one is used) in all the longer 45 cal. cases.

The only reason you would need the actual proper 45 cal. caliber die set is if you have fat (expanded) cases fired in another gun and they won’t enter your chamber. Such fat cases will have to be full length resized and then can be fire formed in your own rifle.

This same rule would also apply to “fat” cases of any caliber. You would have to get a proper full length resizing die to squeeze down those cases to fit into your chamber but once fire formed in your gun you would only neck resize thereafter.

A fired or new case will have too large a neck diameter and the bullet will not be held snugly or in a straight alignment. The case neck should be resized down to a little undersize for a distance equal to where your powder wad will be located.

A special “neck sizing” die can be obtained from several die manufacturers or the above mentioned 45-70 die used when set to just work the case down to the neck area. Then the neck is expanded using the expander plug to a size which will grip the seated bullet firmly but not so tightly as to change the bullet diameter. This operation also opens the case mouth into a slight funnel shape to allow easy entry of the lead bullet.

This funnel effect is called the “bell” or “bell mouth”. The thickness of brass in the neck area will affect how much case “spring back” occurs and may require a larger expander plug than came with your die set.

Die manufacturers can supply expander plugs of different sizes.

As a general rule, the expander plug is made . 002″ smaller than the bullet being used and this will commonly produce an inside diameter of the case neck which is .002″ smaller than the bullet, providing a good grip on the seated bullet.

However…variations in brass hardness, neck wall thickness and other factors can make it necessary for you to make or purchase an expander plug of a different diameter in order to obtain the desired neck tension on your particular bullet.

Many 45-100,110, and 120 brass have such thick neck wall dimensions that an expander plug of .460″ diameter may be required to allow a good grip on the .459″ bullet being used.

If you are using a very light weight bullet for your caliber, it is usually necessary to apply a firm crimp at the case mouth in order to create some resistance and allow explosion pressure to build up properly before the bullet starts moving.

The reason is because the primer blast will start the light bullet moving before the main powder charge can get fully ignited. Accuracy will be poor unless the bullet gets a good stiff kick on the base which obturates it properly into the groove diameter of the barrel. Heavy weight bullets have enough weight to resist primer movement and usually don’t require any actual crimp in the case mouth. This is another of the subjects worth experimenting with to see what works best. Only trial and error can show you what is required for your bullet and case type.

Because these cartridges are only used in single shot rifles there is no need for a crimp if the bullet is fitted firmly into the neck. In fact use of a crimp would create another variable since crimps vary with small case length differences. It is well known that having no crimp at all produces the most consistent neck tension and accuracy so if you can get away without use of a crimp then do so and see what results you get.

However…if you are reloading for a lever action rifle, a good crimp is required along with a flat point bullet in order to work safely in the tubular magazine.


When neck sizing, full length resizing, neck expanding, removing a bell mouth or adding a crimp to the case, the brass is being “worked” and is gradually hardened to a point where it may split or crack. For this reason, it is advisable to size down as little as possible so that the expanding operation tends to work the brass as little as possible.

Straight wall cases such as the 45-70, 40-65 and others of this type do not require much metal working so the need for annealing the brass is reduced greatly. Bottle neck shaped cases do require more metal working so they will tend to need annealing more often. Modern high power rifle cases need annealing quite often due to the extremely high internal pressures being produced but black powder produces far lower pressures and those cases can be reloaded many times before needing to be annealed.

In addition to helping prevent splits and cracks, annealing does one other thing which is perhaps even more important to BP shooters and that is…it keeps the case neck at a consistent softness which promotes consistent neck tension, which in turn promotes better accuracy.

As a case neck tends to get harder its spring-back from the expander plug will change. This changes the grip or tension applied to the seated bullet.

If you start to experience neck splitting I would suggest replacing that lot of cases. Annealing cannot properly restore the internal grain structure of the brass and you are going to be faced with unknown neck tension conditions in such aged cases.

You can anneal your long thin-wall BP cases as follows:

  1. Use a common propane torch or similar low heat type of torch (we don’t want welding heat here).
  2. Work in a dimly lighted area so you can watch the color develop on the brass case.
  3. Have a container of water at hand which is deep enough to cover the entire case.
  4. While holding the case between “bare fingers” so as to feel the heat, apply the flame to the top 1/2 inch of the case while rotating the case in your fingers.
  5. Apply the heat carefully until you can see a dull glow of red starting to become visible on the case mouth.
  6. Immediately drop the case into the water bath to cool it.
  7. Never allow the case to become so hot that you cannot hold it with bare fingers at the base. Depending on your type of flame you should produce the dull red glow in 4-5 seconds of flame application.
  8. How often to anneal BP cases is something which has not been accurately defined.
  9. I have cases which have been reloaded as many as 75 times and yet never shown any signs of splits or cracks. I pay attention to neck tension as well and if a certain lot of cases start to show an increase in neck tension I think it will be time to anneal them all. With my modern high power smokeless powder cases I do anneal them about every 10 reloads.


All brass cases stretch a bit with each shot fired! If allowed to keep growing in length they will get too long to chamber properly and if you are applying a crimp, you will find that the longer case length produces a stronger crimp than does a shorter case length. Use a case length gage or caliper to keep track of case lengths and trim them back to the desired length as required.

As a general rule, the 40-65, 45-70, and 45-90 cases should be trimmed after the first two firings and checked every two firings thereafter. These calibers do not tend to grow much once they are fired a few times. Among the many trimming devices available, the Lee company offers a simple economical device which can be hand operated or spun in an electric drill. It works perfectly and reliably.

The 45-100,110, and 120 cases stretch a great amount during the first 5-7 shots. The 45-120 stretches so much the brass may actually flow into the rifling, causing great inaccuracy and problems. For this reason you MUST measure and trim the case length after each firing until this stretching calms down and becomes very small. New unfired 45-120 cases should be initially trimmed back to about 3.190″ because they may easily grow .050″ or more with the first shot. After this first firing, measure the case length and trim it back an appropriate amount so as to never let the case exceed 3.250″. After repeated firing you will see that the case has stopped stretching much and the overall length can be trimmed to about 3.240″ but always check the case lengths after firing and keep the lengths well under 3.250″.