Saturday, June 6, 2009

Reloading tip: Avoiding the dreaded double charge


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I don't believe modern powder measures that are properly used and cared for will throw wildly varying charges. Perfect charges every time? Regretfully, probably not. Charges with differences of a grain or two? I tend to doubt it. Having used mechanical powder measures from the utilitarian Lee powder scoop, up to excellent quality bench mounted precision micrometer equipped measures, I think every single one is quite capable of tossing a nearly perfect charge each time if used properly.

Still, we shooters hear stories of the dreaded 'double charge' that has dissembled a pistol (or rifle) in a dramatic and unfriendly way.

Does it actually happen? Yes, I think it does. While I suspect the lore might also include hand loaders who made serious mistakes with p
owder selection and handling, loading the wrong powder to the wrong charge, there is possible such a creature as the 'double charge'. It's cause, almost surely a distracted hand loader or poor procedures.

My cure is simple. No distractions, period. I don't reload with friends around usually, and if I do they are hand loaders as well and know when to shut up. In addition, very bright lighting over the bench, and a few simple procedures designed to catch a double charge.


On the rare occasions I use my RCBS Ammomaster progressive press, I have a spot light aimed exactly where it will shine down into the charged case. I glance at every single case before I place a bullet into it. Anything with a funny load gets pulled out of sequence, and investigated. I've never found a double charge doing this, but I see no reason not to be careful.


Loading single stage, as I usually do, I throw all my charges as a set. Then, under the bright lights of the loading bench, I take a moment to carefully examine the charged cases. As the image above shows, a double charged case stands out like a sore thumb. This mornings loading included 9x19 practice ammunition with a light charge of fast powder. A double charge would have easily accepted a seated bullet, but would also have exceeded maximum charge with that powder.

Bright lighting, no distractions, and at least one dedicated examination of the charged cases. Simple measures to eliminate a very real danger.

13 comments:

Crucis said...

I have a RCBS single stage press and a Dillon progressive. I mounted a mirror and a light to allow me to see directly into the case when it moves to the seating die for the Dillon or into the case for the RCBS when the stage in lowered.

I've made it a habit to look into the case before seating the bullet. Some habits are good.

B.S. philosopher said...

Thanks for putting these posts up. I started reloading about 6 months ago and I've really learned a lot. As a baby reloader I am frantically paranoid about double charges. Since I'm working with a Lee anniversary set and not a fancy progressive reloader it tends to not be a problem since I seat the bullet immediately after I dump the charge by hand. It makes for slower loading, but seems safer to me.


Better safe than sorry.

AKA Angrywhiteman said...

#2 center row, ouch!!

Just My 2¢ said...

Oh yes it happens! I keep the blown 45 acp case from a double charge of WW 231 to remind myself to be careful.

Fortunately, the 1911 does not have a fully supported chamber. The case blew out down the feed ramp, blew the magazine out, and burned my hand around the edges of the grips.

My gunsmith adjusted the extractor tension and said it was OK for use. If I'd had a different gun, the result might have been much different!

Lawyer said...

Thanks for your reloading posts. I am seriously considering reloading my own ammo and all you insight really helps.

Now, to find someone with some unwanted reloading equipment ...

Bradley said...

I know that this is often hard in hand gun rounds, but in the world of rifle rounds this is an easy fix, only use loads that are 70% of case volume or better, that way if you do make a double when you lift the funnel powder drops all over the bench, yes its a pain to clean up, but i have not ever shot a double in any of my rifle loads yet.

Carteach0 said...

B.S. and Lawyer, you are welcome!

Crucis, Sounds like a good setup. I went the easy route, with a chicken house flood light pointed into the press.

2 cents, OUCH! I've never tossed a double charge down range, but I have had a squib or two over the years. The worst in my snub nose, and it stuck a jacketed bullet in the barrel pretty hard. The core punched out, leaving the jacket behind. Took some doing to get it clear.

Bradley, You are right. Most of my rifle loads are 90%+ of capacity. No room for a double charge. Squibs worry me too, so procedures are in place to prevent them.

the pistolero said...

Yep, a high-load-density powder is good for preventing the dreaded double charge. I eyeball all my charges as well before I seat the bullet, and I throw every 5th charge on the scale to make sure it's metering right.

Firehand said...

I've never had one throw a double-charge. I HAVE had light charges; some powders, like Unique, are a pain about that.

In rifles I often use a light cast-bullet load for practice. Procedure I worked out is:
1. Count the number of charges I throw, compare to the number of cases; if they don't match...
2. If I can't see into the case well enough, I found a round pencil works very nicely; run it into the case until it reaches the powder, then go down the line.

Old NFO said...

Good post as usual Carteach0! And an excellent reminder to PAY ATTENTION! :-)

Anonymous said...

when i was learning about reloading as a kid, it was my brother's job to use the flashlight and check my father's powder charges. i know for a fact that once in a while he'd throw a double charge on purpose for my brother to find.

now i load on a progressive Dillon press that has a powdercheck system that alarms if the powder is radically different than i should be.

i was never worried about a double charge, since that'd overflow the case. even at high speed (about 800 rounds an hour) i would notice that.

i was always worried about the dreaded squib load, with no powder at all. so i loaded one and shot it. it jammed the pistol (an XD .45) up pretty good. it failed to cycle, in fact, i wasn't sure that it had even fired until i finally got the thing out of the chamber. the primer pushed the bullet a bit out, enough to be too big to easily extract by cycling the slide.

i was concerned that it'd stick the bullet into the barrel and cycle the next round in behind for a dramatic ending to the shooting day.

the results of my little experiment have made me feel a lot better about things. i think that the majority of problems people have involve using the wrong powder or using the wrong charge completely.

sean

ZerCool said...

I started reloading last year and have rapidly acquired LOTS of dies and such. I've reloaded a couple thousand rounds, mostly pistol, and thus far avoided doubles or squibs. I'm doing all single-stage, and have similar procedures to most of us:

- no distractions when throwing powder. I'll have a radio or old movie on in the background, but if my wife comes home, everything gets cleaned up and put away.

- check each case individually with a light.

- dump out a couple cases at random and check charge weight.

I don't mind sizing and priming with people around, though...

Fat Albert said...

On long cases (30-03 303 Brit) with small carges of pistol powders(red dot unique)I uses a piece of wood dowel thats two inches longer than the case and as close to the inside dia. of the neck that will go in. I put the charge of powder into the case and then drop the dowel in and mark the dowel at the top of the neck with a sharpie pen. Then mark the dowel with a red sharpie for about 1" below the top the neck line. I then mark the case-powder-charge(30-06 unique 8grs)on the dowel. After I throw a tray of cases with powder I drop the right dowel in and if I can see red there is something wrong.