How will you teach him (Kubota) the attention to detail required to actually produce SAFE loads? That is something that comes with experience and NOT having any interruptions.
There are steps I can take to dilute the risk of reloaded ammo producing a KABOOM! Essentially, I am trying to follow Bruce Kelly's rules for developing a ROBUST PROCESS.
As a reloader, we must consider the following failure modes:
- Improper propellant. Sadly, many propellants have similar names and vastly different burn rates. Example Reloder-5 and Accurate Arms 5. Grabbing AA-5 and using it in a Reloder-5 recipe guarantees a KABOOM!
- Too much propellant. Cartridges that were designed for black powder are vast compared to the volume of smokeless powder needed. They are vulnerable to double and triple charging. KABOOM!
- Too little or no propellant. Squib loads can leave a projectile lodged in the barrel. The next round creates a KABOOM!.
- Substituting projectiles. In general, heavier and harder projectiles create higher pressures for a given powder load. Different projectiles from different manufacturers have different profiles. One bullet might be contacting the rifling while another is comfortably 0.020" away from the rifling.
- Projectile seated too far back. Projectile can also migrate if insufficiently crimped (called "set-back"). Short, non-bottleneck cartridges are most vulnerable. 9mm Luger, I am looking at you. Reduced volume with full charge of powder can result in KABOOM!
- Projectile seated too far forward. Projectile engages rifling when chambered and the delicate dance of projectile moving forward as powder combusts is thrown out-of-kilter. Usually results in locked-up action rather than KABOOM!
- Old propellant. Propellant (smokeless powder) is energy dense. It has buffers added to it to enhance shelf-life but heat, humidity and time gradually use up those buffers. Once the buffers are consumed, the propellant quickly degrades.
- Wrong primers.
- Brass too long
Eliminate gratuitous variation
Start with just one chambering. In today's environment, .223 Rem is the single best starter cartridge. The demand is unlimited and it is forgiving cartridge vis-a-vis the errors listed above.
|If you look at the maximum load, Grs column you will see some numbers with the letter "C" after it. Those are compressed loads and they crunch when you seat the bullet. Compressed loads are somewhat self-limiting on a powder over-load. Source|
Pick ONE bulky powder near the slow end of suitable powders, preferably one that is a "compressed load" at the maximum. Don't have keep any other powders in inventory or, at a minimum, don't have any other canisters of powder outside the powder locker.
And here is a novel thought: The starting powder load can probably do everything the shooter needs his rifle to do. Does it cycle the action? Can he shoot it well out to 200 yards? Simple fact, expanding bullets penetrate better when they are going slower. That is not a bad thing.
The potential for double powder charges increases a hundred-fold when processing blocks of ammo. The best way to reduce that risk is single-lot processing.
- Pick up one primed case.
- Drop the measured powder charge into the case.
- Immediately move to the press and seat the bullet.
Pick one, general-purpose projectile in the middle of the generally accepted range of projectile weights and buy a metric boat-load of them.
For example, you can buy 30 grain .224 projectiles and you can buy 95 grain projectiles. The 5.56mm NATO was released to the civilian market with a few modifications as the .223 Remington. The 5.56mm NATO was designed around the 55 grain bullet. It is still a good weight choice and any .223 Rem rifle or 5.56mm NATO rifle will stabilize and shoot most 55 grain bullets with ease.
Pick a general purpose bullet.
You can buy extremely frangible 55 grain bullets and you can buy 55 grain target bullets and you can buy 55 grain softpoint bullets that expand, but not explosively. You can kill prairie dogs and starlings with softpoints even if it does not turn them into red mist like the super-frangibles. You can even harvest Whitetail deer if you poke them in the ribs or shoot them between the eyes.
You can shoot holes in paper with softpoints. You might not be able to beat your competitive shooter buddy using special-purpose bullets, but is that why you have an AR?
|Typically, the rim of the case is crimped into the cannelure which provides additional bullet retention. The cannelure also provides a handy visual reference for bullet seating depth.|
Pick a bullet with a cannelure. That is a major reason for reloading .223 Rem instead of 9mm or 40 S&W. 9mm and .40 bullets don't come with cannelures because the case headspaces on the rim of the case. The cannelure is insurance that the newbie cranking out ammo won't make ammo that is too long, too short or ammo that will set-back under recoil. Not a guarantee, insurance. From a terminal ballistics standpoint, the cannelure mildly restricts the bullet expansion thereby increasing penetration.
Primers make a difference. The two "preferred" primers for AR style rifles are CCI 41 primers and Remington 7-1/2 primers. Or use what your load-book calls for. Pick your primer and buy a thousand or five.
Brass too long: This is where reloading stops being fun. Yanking on a handle is fun and you have a finished round as a reward. Trimming brass is tedious and does not feel like you are actually doing anything.
Here is an idea. Take a pair of verniers and lock them at the maximum allowable case length. Then have the newbie sort the brass. Too long goes in a red bucket and not-too-long goes in a green bucket. Then charge him 3X for the not-too-long.
Testing the set-up
Don't start cranking out production. Load up a few. Cycle them through the intended weapon without firing. If all looks good and the Overall Length is good, then shoot them over a chronograph and see if the velocity is in the expected range.
Not every cause of KABOOMS was addressed, but I think I hit the high-runners. Reloaders, if you can think of one that I missed, PLEASE make a comment.
No, the newbie will not be an expert reloader when he is done. A reloader sets-up and runs the reloading process. The newbie merely ran the process the way a factory worker runs the equipment on the factory floor.
And while you, the experienced reloader, made most of the critical decisions you still want the newbie to verify that the label on the powder jug matches the powder specified by the load-book. You want the newbie to verify that the brand and weight of the projectile matches the load-book. You want to show the newbie how to visually and/or tactilely inspect the brass, the thrown powder load and the finished round for every round.