Many high volume shooters reload their own ammunition because it is cheaper. Many shooters begin reloading and continue because of cost. However, depending on the kind of shooting, other reasons to reload take on increased importance to the reloader/shooter. How much you save will depend on the kind of shooting you do and how you go about reloading. If you are a low volume shooter and include the cost of equipment and your time, it will take you a very long time to break even. Even if that is your situation, you may still find reloading to be enjoyable and profitable to your shooting experience. The percentage savings could be 30% to 70%. Unfortunately, a concrete savings answer just isn't possible. Do you buy in bulk when things are on sale? Do you purchase a few at a time from an expensive retailer? My personal experience is that I can save about 50% reloading comparable quality bullets and components.
Ammunition Availability at Any Price
The 2008 Presidential Election results in the United States caused a run, almost panic buying, on ammunition, firearms, and shooting supplies that lasted almost a year. The little ammunition that was available became expensive and brands I had never before heard of were all that was available. Often the cases were steel with Berdan Primers making them unsuitable for reloading. Reloadable cases are usually made from brass and use replaceable Boxer Primers. During this time, I was able to continue shooting because I had enough supplies and was able to reload my own ammunition.
Every year, new cartridges are introduced. It is impossible and impractical for retailers to carry every available cartridge. I live out west in a small town with no retailers. A small nearby town has a convenience store that sells some ammunition. They carry two or three boxes of 12 gauge shotgun shells. They carry several boxes of 22 Long Rifle. They stock a couple of boxes each of 30-30, 30-06, 300 Win Mag, .308 Win., and .223 Rem.. They carry pistol cartridges for .357 Mag., 38 Special, 9 MM Luger, and infrequently a box of 45 ACP. If my tastes are more exotic, I am going to drive 25 miles to a larger town. Even there, a lot of infrequently seen cartridges are not available. Your choices are to reload or rely on an internet retailer for your ammunition of choice.
Recently, Federal came out with a spiffy new pistol cartridge, the .327 Fed. Magnum. It was supposed to give near .357 Mag performance with much less recoil. It was touted as a great cartridge for those carrying a small revolver concealed. Reduced recoil with substantial stopping power seems like a great combination. I have seen one pistol chambered for that cartridge, and no ammunition carried by any local sporting goods or shooting store. At least around here, if you want to shoot the .327 Fed. Magnum, you had better consider reloading.
Bullet of Choice Availability
Over the years, manufacturers have produced a staggering array of specialty bullets and an increasing number of shot options. Gun writers tout the advantages of the newest and best. Manufacturers fill shooting magazines with exotic advertising. Shooters start salivating for this or that feature. Local retailers can't possibly stock everything. Even the biggest retailers only stock a small percentage of what is available. If you are excited about a low volume specialty bullet, your only choice may be to special order the ammunition or order the components and reload your own ammunition. Many of the bullet offerings are not available from any ammunition manufacturer, making reloading the only way you are going to be able to shoot those specialty bullets.
Getting the Most Accuracy From Your Rifle
When a rifle is fired the barrel begins to oscillate or vibrate. Experts agree that to get the most accuracy from a given rifle you want each bullet to exit the barrel at the same point in the oscillation sequence. For our purposes, I call that the sweet spot. In almost every shooting magazine where firearms are evaluated, you will find a table showing brand/type of ammunition, velocity, and accuracy. Different manufacturers load ammunition to slightly different pressures and velocities within the industry limitations. Different powders have different pressure curves causing variations in the vibrations. Bullet weight, shape or constructions can also impact this phenomena. Ammunition that exits the barrel closer to the sweet spot, or same point in the barrel oscillation, will be inherently more accurate. Two apparently identical rifles from the same manufacturer may have different ammunition sweet spots. Reloading allows us to adjust or tweak the components of ammunition in search of that sweet spot for your firearm.
The variables you can manipulating are brand of primers, type or weight of bullet, bullet seating depth, powder charge, and type of powder.
Primers from different manufacturers ignite the powder at slightly different rates, changing the pressure curve and bullet velocity
Popular bullet calibers have hundreds of bullet options in brand, construction, weight and style. Even less popular calibers have a many bullet choices for reloaders. I had a 1903A3 30-06 that was most accurate with 150-168 grain bullets. It didn't like 220 grain bullets at all. I occasionally loaded 90 grain bullets to plink with. They weren't particularly accurate but they were fun to blow up jugs filled with water. You can't change the rifling twist rate in your barrel, but you can choose bullets in a the weight range it is optimized for. It has long been known that heavier bullets require faster twist rates to properly stabilize. Heavy for caliber bullets in my old 30-06 will keyhole. That is, they fly like a wobbly football and make oblong or keyholes in the target. A current AR 15 manufacturer lists optimum bullet weights which differ depending on the rifling twist rate. An internet search of rifle twist rates will give you information to select bullets in the weight range optimized for your barrel. I'll write more about this in a later post. Obviously, you want to begin with bullets suitable for your purpose in a weight range compatible with your barrel twist rate.
Reloading manuals give several powder brand/type choices for various bullets. Choose a powder that works well in the weight range of bullets you are interested in. Changing powder charge weights slightly is the cheapest and easiest place to begin your load optimization search. Begin with powder charge weights 10% below maximum. Make 5 bullets at charge weights or 10%, 8%, 6%, 4%, and 2% below Maximum. One of those groups should shoot better than the others. That is the place to begin further refinement OR if that is good enough for your purposes, you are done.
I have discussed a few of the reasons that reloading may be right for you. I didn't touch on the fact that reloading is fun or that shooting your own hand loads tailored to your specific firearm is extremely satisfying. An example from fishing seems appropriate. Catching a fish is fun. Catching a fish using a fly or lure you personally constructed is eminently more satisfying. Shooting tiny groups is fun and fulfilling. Shooting tiny groups from ammunition that you personally constructed is more fun.