Modern Load DevelopmentBy Matthew Cameron
- 22nd Oct, 2019 Oct 22, 2019, 12:00 AM
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Cartridge load development was once a simpler task that it is today, mainly because the often confusing range of components did not exist. Projectiles were either pointed or round-nosed with a lead tip, the range of powders was minimal and the same applied to primers.
Today the reloader is confronted with a huge range of powders, primers and projectiles, the combinations of which would give a computer a headache trying to work out the best combination for the task at hand. We could throw brass, dies and various reloading manuals into the mix to further complicate the issue. So where do you start to sort out the wheat from the chaff?
Today there is much reliance on the electronic media and the easy access of online information. All such information has to be viewed with some suspicion irrespective of its source. The real problem with the internet is that it is uncontrolled, whereas anything in the print media has at least passed the eagle eye of the editor, so that anything outrageous or unsafe should have been eliminated.
Almost invariably the initial selection relates to the projectile and what we require it to do. The first question is, what do you intend to shoot? At the bottom of the scale we have rabbits and hares followed by perhaps goats and then pigs, with deer at the top of the heap. You can probably find a rifle/cartridge combination suitable for varminting that would also be acceptable for light-bodied deer.
“In the real world there is nothing wrong with Plain Jane soft-point projectiles for most hunting requirements. It’s when you get to the outer limits of range and velocity that premium projectiles earn their keep.”
However if you’re hunting bigger, tougher animals like bull tahr, red stags, wapiti or sambar it makes sense to use a heavier calibre. You want to stop the animal where it stands, or at least prevent it from moving far after it’s hit. Associated with the calibre are projectiles of premium quality, able to mushroom and penetrate through bone and muscle into the vital organs.
With varmint type projectiles you have to be wary of their velocity. Some modern projectiles carry a warning not to exceed a certain velocity or you risk them breaking up in flight, a victim of too much speed and/or twist.
Many projectiles have plastic tips that encourage expansion and a large percentage provide a bond between the lead inner core and copper casing. Usually these bonded projectiles are confined to hunting larger animals. In the real world there is nothing wrong with Plain Jane soft-point projectiles for most hunting requirements. It’s when you get to the outer limits of range and velocity that premium projectiles earn their keep. Most deer, simply because of their size, demand the use of a premium projectile.
“The other issue in relation to modern projectiles is using the correct barrel twist. This is a function of both projectile length and muzzle velocity.”
Although members of our hunting group (varmints/pigs/deer) have tried many different projectile designs some of the older projectiles still provide useful service in both older and more modern calibres. Several have stood out but personally I keep coming back to one design, the Nosler AccuBond.
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We have used Nosler Ballistic Tips, Hornady SSTs, Barnes, Speer and many others but the AccuBonds have always worked for me in a variety of calibres. As its name suggests the AccuBond is another bonded design with a plastic tip that causes the bulk of the projectile to expand on impact – the mushrooming and the bonding work together. Obviously the thickness of the jacket plays an important role in determining how and when the expansion occurs.
We have also used Nosler Ballistic Tips from .224 calibre at 40 grains in weight and above to 180 grains with good results and fine accuracy. Personally they have accounted for many deer in my .270 Winchester at modest velocities (thereby reducing barrel wear) using 140 grain and 150 grain weights.
For hares and wallabies the 40, 50 and 55 grain versions are superb as long as you do not want to save the skins! A professional shooter I know rates them very highly although cost is a concern for some hunters. Some heavier premium projectiles can cost in excess of $2.00 each.
SOMETHING FOR EVERYBODY
Do your research and you’ll find a specific projectile for your needs. The number of projectiles keeps increasing so check your local gun shop regularly. Some premium projectiles suitable for heavier game are designed mainly with their terminal performance (mushrooming and penetration) in mind rather than absolute accuracy. This is fair enough when you consider the size of the animals.
The other issue in relation to modern projectiles is using the correct barrel twist. This is a function of both projectile length and muzzle velocity. With the increasing number of heavier projectiles available in most calibres, rifling twist is an issue that needs to be understood if you are to attain the accuracy you seek. It can be a particular problem with varmint cartridges. Often modern rifles have barrels that are designed for the projectile weights available at the time of the rifles’ original introduction. The .22-250 Remington, .220 Swift and the experimental .224 Remington are typical examples.
“The final piece of the modern reloading puzzle is powder and its selection, another minefield for the gun writer!”
There are continual questions on the internet about primers but in my view not much has changed here. For cartridges up to about .30-06 we used standard primers, for anything above we go for a magnum primer. The situation with small rifle primers is a bit more complicated simply because the thickness of the primer cup varies between brands, whereas with large rifle primers the thickness is a standard 0.027 inches. One gentleman of my acquaintance who shoots a lot always uses a magnum primer with his .223 Remington loads, in his opinion it just makes a better cartridge. His advice is worth listening to.
The final piece of the modern reloading puzzle is powder and its selection, another minefield for the gun writer! Many years ago I read of a sure-fire load for a particular rifle/cartridge combination in a US magazine. The author claimed that the load had worked in half a dozen rifles he had owned in that calibre. So for my own rifle I loaded the same cartridge using the same components. The “groups” left a lot to be desired and did not meet my accuracy requirements. Loads need to be developed for each individual rifle. Another lesson is – never fire someone else’s reloads in your own rifles. Without going into long detail I have witnessed occasions whereby a moderate load in one rifle is a veritable bomb in another. Sticky if not stuck bolts, blown primers and damaged rifles have resulted.
In my experience usually the most accurate load is a grain or two below the maximum specified in the manual, irrespective of rifle’s quality. However there are exceptions to this and some cartridges seem to operate best at full charge weights.
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There are simply too many variations between individual rifles to suggest one particular load may work in another if accuracy or velocity are the sole criteria. Perhaps a particular group of powders with similar burning rates will be suitable in a particular cartridge case. For example, powders with a burning rate centred on IMR 4350/AR 2209 seem to provide good accuracy and velocity with a variety of projectiles in the .243 Winchester.
There are more new powders than there are projectiles and there are several that can improve the performance of older cartridges. Often this is because newer, much slower-burning powders are useful when it comes to propelling the newer and heavier projectiles on the market.
There are two consideration however, first the overall length of the cartridge may be dictated by the length available in your rifle’s magazine. This in turn limits the available powder space within the cartridge, making it difficult to get enough slower powder into the case to provide better velocity. In addition even if you are able to get the extra powder into the case any velocity increase may be minimal. The other problem is that longer, heavier projectiles require faster barrel twist rates. On older rifles twist rates tend to be slower and reflect the types of projectiles available at the time of release to the public. No one said it was easy!
“There are simply too many variations between individual rifles to suggest one particular load may work in another if accuracy or velocity are the sole criteria.”
Which powder should you use initially? I started load development with a mid-range powder for the projectile weight. The logic behind this is that if the powder proves unsuitable you can move in two different directions. For heavier projectiles in relation to calibre perhaps moving towards the next slowest powder might be useful, however this is not always correct. There is no magic formula, you just have to load and shoot then look at the evidence on the target!
Modern powders continue to improve, producing less barrel fouling due to their cleaner burning. In addition modern powders are less affected by external temperatures, an important factor in hotter climates. Success in relation to modern load development really comes down to research and experimentation! There are many choices to be made.
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