G20 KB! - Ideas on what happened?

[DM1906]

Doesn't anyone make a scale you can set to +/- say 2gr's that will give an alarm or something? I don't reload but would for sure search something like that out. If that doesn't exist I think I would just weigh them when finished before putting in the box.

It isn't the scale.  A scale is used for checking charges, not creating them.  Some dispensers have a scale, that checks the powder weight as it's being dispensed.  Most aren't accurate at a speed for anything other than (slow) single stage handloading.

Powder charge volume checkers are available for progressive and turret type presses.  In almost all cases, they will detect double charges and very light charges.  If set up correctly, they'll always detect a double charge or a light enough charge to cause a squib.

Weighing complete cartridges is rarely helpful for detecting over/under charges as little as 2 grains.  Unless all of the components are weighed before loading, it's essentially useless.  If using recycled brass and bulk target bullets, they can vary more than 2 grains, even with a correct powder charge.  Other factors of the handloading process can be equally as dangerous.  Handloading is a package deal.  We have to get it all right, every time, or bad things can happen.  There's a very fine line between an "unpleasant experience" and a full house KB!  Most "Kaboom!s" you hear/read about are in the realm of an "unpleasant experience".  I've seen the real thing more than once, and have yet to read of one here, or the other forums.  Bruised hands and scattered pistols don't count.

The most dangerous risk with handloading, no matter how you do it or what equipment you have, is distraction, and it can happen at any stage of the process.  Grab the wrong powder, fail to verify the load recipe and dimensional data, check the bullet weight, use incorrect primers (small pistol, small pistol magnum, small rifle and small rifle magnum are all exactly the same size), for example, and bad things can happen.  I handload a couple dozen caliber/cartridges regularly, so I'm at a higher risk compared to someone who loads only one with the same components.  Even when you do everything right, unexpected things can happen.  Usually it's minor and uneventful, and serves to give yourself a swift kick in the seat.  Other times, it can be a component failure, and the KB! still happens.  Hopefully, it won't be catastrophic.  Secondly, bad advice will get you into trouble.  Just because something works for one person doesn't mean it work for everyone, and every firearm has unique characteristics.  If it can't be verified by published data or extensive personal experience, it can be a recipe for disaster.

[sqlbullet]

The Hornady Powder Cop and RCBS Lockout die both are designed to alert the reloader of an issue on a progressive press.

But, the are of less value on a single stage press.

In general issues with powder variance that are problematic result first from distraction, as DM1906 says, and second from trying to mass produce loads that are right at the very, very edge, which is really a form of distraction.