Witnessed my first KB last night FNS 40

[vaglocker]

Some guy and his wife get set up in the lane next to me. I already know it's going to be bad news when I see him pull loose ammo out of his pocket to shoot. First shot KABLOOEY! I look over and the bottom of the magazine has blown out, the gun is about a half inch out of battery and the dude is trying to figure out what the hell just happened. I can see that the frame is now bulged out as well and the slide won't move forward or back. Range officer comes over to see what happened and I hear the guy say that these were the first reloads he had ever made. I even heard him say he only eyballed the OAL and wasn't using calipers. Most likely a double charge i would guess. I would have asked to take pictures of it but I wanted to keep my interaction with this idiot to a minimum.

[JV_]

Improper OAL can be just as devastating as a double charge.

[NETim]

If you want to reload, you have to read the damn instructions.

[Al T.]

I hear the guy say that these were the first reloads he had ever made.

Anybody taking bets that they may also be his last, LOL? ;)

[pangloss]

When I started reloading (early 90s), I read that 9mm was very subject to pressure spikes if the bullet was set too deeply. That (and the fact that I only had/have a single stage press) was enough to keep from reloading 9mm. I suspect that .40 is just as "delicate" as 9mm.

[JodyH]

Interesting article:
Battered Bullets: Does bullet setback matter? (http://dailycaller.com/2013/03/05/battered-bullets-does-bullet-setback-matter/)

1641

[Tamara]

Interesting article:
Battered Bullets: Does bullet setback matter? (http://dailycaller.com/2013/03/05/battered-bullets-does-bullet-setback-matter/)

1641

Andrew's article was interesting, if not dispositive. Piezo testing has shown serious pressure spikes associated with setback; IIRC, only about a tenth of an inch in some .40 loads is like feeding your gun a 'red pill'...

[SecondsCount]

Interesting article:
Battered Bullets: Does bullet setback matter? (http://dailycaller.com/2013/03/05/battered-bullets-does-bullet-setback-matter/)

1641

I see a couple holes in that article/test-

1. When looking for pressure signs you would typically start by observing the indentation that the firing pin makes in the primer, not checking the slide and barrel for cracks. If the indentation is flattened or starting to flow back into the firing pin channel then you know that pressures are very high.

2. Powder burn rate. I am guessing that the powder used in the Speer Gold Dots has a slower burn rate which will affect the results that the writer is looking for. Faster burning powders, such as Hodgdon Clays, are very sensitive to bullet setback, even in a 45 ACP. Also, you can easily over, or even double charge a case with fast burning powder because they take up less volume in the case.

[ScotchMan]

Even with an improper OAL, it seems pretty unlikely that this guy was starting with a minimal load, like every guide ever suggests. He probably found a published load, which are always maximums, and then "eyeballed" his OAL, causing a pressure spike. As was mentioned, RTFM before trying this stuff.

I never went up from the minimum load. Why do I want to spend more money on powder to have higher velocities to shoot paper at 7-15 yards? Recoil is similar enough for training purposes, I save money, and I have a super big margin of error. Ideal.

[JV_]

Even with an improper OAL, it seems pretty unlikely that this guy was starting with a minimal load

I disagree. I've seen 75-100 fps, and significant felt recoil changes, when reducing the OAL on a good load .035". I'm sure that another .035" would have been devastating.

I don't think a guy new to reloading (who doesn't own/use calipers) would know this, nor do I think they could easily spot relatively small OAL changes as he fondles a few of the rounds in his palm.

[ToddG]

If he eyeballed the OAL maybe he eyeballed the powder charge, too. Trying to figure out exactly which dumb mistake(s) were made here is futile.

[DBLAction454]

I wonder how well a GUN that was eyeballed and never measured when being engineered would perform?...hmmm (grabs tools).....hospital report coming soon

Glad he or anyone else wasn't hurt and hope he learned a really good lesson. Feel bad for the gun that's destroyed because of the dumbassery

-DBLAction454

[ToddG]

I wonder how well a GUN that was eyeballed and never measured when being engineered would perform?

Didn't TCinVA do that on Gun Nuts last year?

[bgw45]

If he did not need a caliper i wonder if he needed a powder scale or dropper??