What cause squib loads?

[fourdollarbill]

Please explain how a properly ignited, uncontaminated powder charge of sufficient weight could leave a projectile in the bore.

Yes now I see the confusion... I'm not claiming a "proper charge" of "sufficient weight" to cause a squib. The op stated a "min-h110 load" so that's what I was basing my argument on in addition to his claim of "and bunch of h-110 falls out that wasn't burned". I think I have a clarity issue.

And yes I did write this

I have a 38 spl load with an AA9 recipe that shoots fine in a 6" barrel but leaves alot of unburnt powder and occasional squibs...

I should have clarified and typed in... I have a 38 spl load with a minimum charge of AA9 that shoots fine in a 6" barrel, leaves unburnt powder in a 1.75" barrel - but leaves an occasional squib in both.

Yes - my bad and I claim it.

 

[ranger335v]

"BUT this topic on barrell length vs powder could be a pretty interesting forum topic. "

The timeressure curve is constant for any given load, barrel length, as such, has no impact on that. Most of the time the peak pressure will occur within a couple of inches of bullet travel.

Light loads of H-110 are a problem waiting for a time. That's a full charge powder and should be used as such, including the use of magnum primers. A starting charge, a standard primer and little crimp all adds up to irregular burn rate, nothing else is needed for a "squib."

Your loading range cries out for the use of 2400, Herco or Unique.

 

[mahansm]

I've gotten squib loads with 296 in .357 Magnum. Gun was S&W 686 6", cases IMI (new), bullet 125 gr JHP, using Winchester small primers and the listed load from Lyman 47th edition. About 1 out of 6 did not ignite the powder, leaving a bullet either stuck in the barrel or bridging the cylinder gap.

None fail to ignite using Winchester small pistol magnum primers.
Winchester large pistol light it just fine in my .44 mag.
Winchester large rifle do the job in the .500 S&W (all using 296 at listed charge weights).

 

[fourdollarbill]

I've gotten squib loads with 296 in .357 Magnum. Gun was S&W 686 6", cases IMI (new), bullet 125 gr JHP, using Winchester small primers and the listed load from Lyman 47th edition. About 1 out of 6 did not ignite the powder, leaving a bullet either stuck in the barrel or bridging the cylinder gap.

The listed load from Lyman... was it the recipes minimum load, in-between load or max load that did not ignite with standard primers? I would assume the minimum. I had an H110/125grJSP load from the 49th that did the same when I started at the minimum and I tried to cheat using CCI 500's. I thought it was my crimp so I tightened it up. The crimp did help but there was still a lot of unburnt powder. Lesson learned H110/296 - start in the middle, work up and no matter how you try it - use mag primers.

 

[mahansm]

The manual only listed a single charge weight for 296, with the words, "DO NOT REDUCE".
I'll look up the loading at home tonight.

I've also seen manuals that claim that a 296 loading should not be reduced more than 3% from the listed max load.
I use 2400 for "light magnum" and switch to Unique, 231, or one of the Accurate powders for light loads.

 

[EddieNFL]

here's a sample:

158 GR. HDY XTP Winchester 296 .357" 1.580" 15.0 1418 28,600 CUP 16.7 1591 40,700 CUP

 

[sonier]

pressure curves and barrel weights are a very interesting topic. Im gathering fast powders are really neccesary for snubnoses. Lots of great info on this thread

 

[lgbloader]

squibs... I even hate the way the word sounds.

LGB

 

[EddieNFL]

Sounds a little...navyish?

To my swabbie friends, just a joke.