In his recent article RELOADING PRIMER, Jamie cautioned to only use CURRENT loading data, checked from 3 reputable sources, when selecting powders and charge weights for a pre-selected bullet while handloading. That statement is extremely good advice, and got me to thinking about loading data and load selection.

With over 20 years of reloading experience, I recall that every time a new loading manual was released a lot of hoopla surrounded it. Just why did a new manual differ from its predecessor? Was it just the introduction of new powders and bullets, or was there something more?

Of course, nothing is static. New powders are introduced; and some old numbers are discontinued. Unavailability of some of the popular imported powders was easy to explain. In the late 70’s and very early 80’s, importing some of the excellent Norma and Alcan powders became so mired in import/export law and fees of that era, that it was simply priced out of the market. Today, new trade agreements and laws have allowed it to become economically feasible to once again sell imported powders in the US. Yet, it’s hard to understand why a popular domestic powder would cease to exist.

It stands to reason that if a powder has disappointing sale numbers it will be discontinued. That’s the simple market law of supply & demand. However, what if a powder has excellent sale numbers and there is a load surrounding it that has achieved status as “the load to use”, why discontinue that powder? I recall when one of the major US manufacturers announced the discontinuation a certain popular pistol powder. There was much hand wringing and gnashing of teeth. A run on dealers quickly depleted all available stocks of that powder. After dealer stocks were gone, a few fellows who had stock piled supplies, were selling it at twice the original price! Why would a producer discontinue a product that was in high demand?

Loading data can be garnered from sources other then reloading manuals. Powder manufacturers also put out loading data for their products; this is usually in the form of pamphlets. Pamphlets are superseded with much greater frequency then manuals. The powder manufacturer will caution to only use the current data. One concern even went so far as to put the statement “Destroy All Previous Lists” in their latest pamphlet. Is the powder manufacturer saying their previous data is faulty? One would hope not!

On occasion, a faulty batch of loaded ammunition does leave a factory. On the very rare occasions when this does happen, the manufacturer has an immediate recall on the affected lot number. The fault is usually that the subject ammunition develops excessive pressure.

Speaking of pressure, there is more then one standard for pressure measurement. There is CUP, PSI and in Europe, the CIP system is used. For an explanation of the PSI, CUP and CIP system see the article on this site “The Spanish Mauser Inquisition”. As has happened at least once in the past, revolver ammunition loaded by a European factory, and factory rated as “standard pressure” by the CIP method was re-rated as +P+ after it hit US shores.

Domestic ammunition producers use non-canister grade powder. What that means is if a manufacturer has been using 58 grains of Buford’s Blasto in the 800 Belch-Fire Magnum cartridge, when a new shipment of Blasto is received from Buford’s Powder Works, the manufacturer will have to determine if this latest batch of Blasto is comparable to the last. Since it is non-canister grade powder, chances are it won’t be exactly alike.

 

What’s the difference between Non-Canister and Canister grade powder?

Non-canister grade powder is supplied to commercial ammunition manufacturers only. Powder producers use a formula to produce the next batch of powder, one would think that if the same formula was used the powder would be exactly alike. It’s not, that’s why the ammunition manufacturer has a complete ballistic lab. The lab tests each lot of powder received to determine what an appropriate charge weight is. The loaded round must meet all preset velocity & pressure specifications. Canister-grade powders are made for sale to the general public. They are blended for consistency. They are as close ballistically to the last lot of powder as can be made possible. Look on a container of powder; there is a lot number somewhere. The lot number is usually a combination of numbers and letters. It may be on the side or the bottom, but it will be there. If you buy powder from the same dealer and your next can of powder has the same lot number as your last can you are set, if not, then use the procedure below to test the new batch of powder.

The manufacturer may find 56 grains of this latest lot of powder is safe and meets the requirements for this cartridge. Perhaps the next lot of Blasto will need a load of 59 ½ grains to meet specifications. Powder supplied to handloaders is a bit different, it is known as canister-grade.

The recommendation to: “Reduce a load 5% to 10% when you open another powder container of a different lot number, then see if the load needs to be adjusted either up or down after testing it in your rifle.” is extremely good advice. While lot-to-lot variation of canister grade powder is very small, it can and does exist. It will show up when a load is at or very close to maximum for that cartridge. If one normally uses a somewhat reduced load, selected from the bottom loads in a manual, one gets a bit of grace.
 

The Same Powder, But Different Lot Numbers

 

Um, I don’t have a ballistic lab, what do I look for?

Provided the brass has been trimmed to proper length and there is a bit of free travel (.015 to.030) before a proper size bullet encounters the rifling, excessive pressure may be determined by the following. (The following in not inclusive nor intended to be) Some subjective pressure signs include hard bolt lift, difficult withdrawal of a empty case from the chamber, a primer which has been mashed flat, a leaking primer, a primer which falls out of a cartridge case, the head stamp of the cartridge taking on the imprint of the ejector. The reason we say “subjective pressure signs” is that only a ballistic lab can determine actual pressure. What we are doing is checking an assembly of components against our individual rifle.

Since the load is already reduced, lot-to-lot variation will have much less effect on that cartridge. Mil-surp rifles usually have roomy chambers and generous freebore. Those two conditions contribute to reduced pressures. However, let’s consider this; what if one has already carefully worked up to a safe maximum for a particular mil-surp rifle with a particular lot of powder, a particular lot of bullets, a particular lot of primers and a particular lot of brass?

Our handloader, who has been using Blasto, has worked up a safe max load for his rifle. His last can of canister-grade Blasto, lot # AB107, is empty. The handloader buys another can of canister-grade Blasto from the same dealer he always buys from. Without checking the lot number, he just starts filling cases with powder. The new can is lot # LG321. Since the load was already at maximum, there is a chance of excessive pressure by just using the old load without reducing 5% to 10% first and checking for pressure signs. Of course, there is every chance the load may shoot a bit softer also. Whenever we deal with safe max loads, every component must be looked at with a critical eye.

Right after I got a Finish 39, I bought 100 rounds of new, loaded S&B 7.62X54R. I felt this would be a good source of reloadable brass. S&B ammo is brass cased, made in Eastern Europe and has Boxer type, non-corrosive primers. I fired 5 rounds. All had hard bolt lift and were hard to extract from the chamber. As I had already done a complete examination on the rifle, I knew the chamber was clean and polished. The ammo was just loaded a tad hot. I pulled the bullets, weighed the powder from 10 rounds and found the average charge was 57 grains. By reducing the charge to 52 grains, a reduction of 8.8%, the rounds performed perfectly. I reloaded all the rounds with 52 grains of the factory powder and the original factory bullets. The remaining 475 grains of powder were scattered in my wife’s roses. Powder is loaded with nitrates, great fertilizer (in small amounts).


Let’s revisit the question posted earlier. Why would a producer discontinue a powder that was in high demand? The answer lies in the manufacture process of smokeless powder. Some individual powder formulas are very forgiving; one lot is usually so close to the last that a simple blending process allows the powder to be canister grade. However, some powders are quite persnickety. Trying to get lot-to-lot consistency is difficult, and the blending process won’t allow the powder to be close enough to the last lot to qualify as canister grade. But, it’s still good powder, and it’s sold to the ammunition manufacturing industry as non canister grade. They will conduct the ballistic lab work to determine what a safe charge is.

Certain powders are very flexible; they can be used in a wide range of cartridge types and sizes. They tend to very easy to produce and have extremely close lot-to-lot consistency. Needless to say, these powders enjoy a very successful history for both military and civilian use. Examples of these are the IMR series of powders. Such numbers as 4895, 4064, 30301, 4198, just to name a few, have been around for a long time and will continue to be recommended.

Primers can have an interesting effect on loads. While a change from standard to magnum primers will raise pressures, which in of itself may not cause problems, the problem is often that a change to magnum primers may cause erratic pressure peaks in individual rounds while the majority of rounds perform normally.

Some loading references specify brands of brass, bullets & primers; others only specify some components beyond powder brand and number. Provided the loads listed are sufficiently mild, this practice is ok, but I still prefer to see all brands posted and what rifle was used in testing. Often a universal receiver is used with an attached barrel.


Another area of concern is brass. Brass capacity varies greatly between brands. Merely weighing cases won’t tell the whole story either. While one may think the heaviest empty case always has the least capacity; it’s not necessarily so. The best method to determine case capacity is by filling the empty case with water and weighing the water.
To check this I took a sampling of 30/06 cases. To ensure accuracy & validity all were resized with the same RCBS die, trimmed to one length on the Wilson trimmer, and then the necks were inside, outside deburred. The flash holes were also deburred.
 

Case Brand	Capacity Of Case In Grains Of Water	Case Weight
MRP	68.5 Grains	193.3 Grains
Federal	68.0 Grains	197.8 Grains
LC66	67.5 Grains	193.8 Grains
PMC	67.0 Grains	197.3 Grains
Winchester	66.3 Grains	183.8 Grains
Remington	65.3 Grains	196.5 Grains

While the case with the most capacity (MRP brand) did weigh the least, the case with the least capacity (Remington brand) didn’t weigh the most.

Many people think military brass will always have the least capacity and weigh more. As can be seen, the LC66 (Lake City 1966, US Military) did not fit this preconceived idea.

Of course these were just 6 once fired cases, not a huge sampling, however it shows that good, trimmed brass can and does vary.

Recall we said the loading manuals and pamphlets have changed over time? The reasons are twofold. The people who write the material also know that components change and they use the latest components in their work. The second reason is most labs have switched from the CUP to the PSI system. The PSI system uses the transducer method, which gives a clearer picture of pressures.

OK, so powder won’t always be exactly like the last lot, brass, primers & bullets all come into play here. So, how are we to know what’s safe? Simple, always use current data, check it against several sources, start with the lowest load and check for pressure signs.

Have fun loading & be safe.