Unburnt powder? 
Squib ?
Interesting. A squib with a light charge of W296?
I am extremely interested in the pic . Explanation please .
The sixgun is a converted Ruger Bisley in 357 Mag. The load was 12.5 grains of WC820 with a CCI550 primer. I used this charge for the first 1000 rounds though the gun with a MagTec 158 grain HP bullet. It shot lights out. The trouble came when I replaced the bullet with the NOE 360-160-WFN in hollow point form. The bullet weight is close to 158 grains but because of less resistance in the barrel the pressure wasn’t high enough for a good burn. I raised the power charge to 13.5 grains & the problem went away & hasn’t returned regardless of conditions.
Not familiar with NOE molds … so wanted to look up some history on thd name couldnt find it even on their own website . But none- the less a squib but not really a squib just an underpowered load due to too light of a charge behind a bullet with less overall mass.
So, you’re saying
That could make fireworks with a revolver 
This happened a few times before I figured the charge was too lite.
I’ve used several of their moulds, all aluminum. Never a problem with them.
Best to play is safe 
Thanks for sharing the details.
NOE stands for Night Owl Enterprise best I recall.
That 360-160-WFN is a good looking bullet.
It’s a nice bullet & easy to cast.
My only reservation is that I’d likely run them full throttle a lot, and I’m not sure if my Marlin will need a gas check or not. I just haven’t tested it enough yet.
I’ve shot some plain based bullets at 38 Special level and they didn’t lead, but I didn’t shoot enough to really test accuracy yet.
I have a full power load worked up with the RCBS 38-150-SWC for another gun, that shoots clean. But I don’t have any cast up right now.
My Marlin has ran semi-wadcutters just fine so far, but I’ve not tested that bullet yet, due to being out.
Yesterday I went to a local gun store to look at a Sigg P2 11. It was unfortunately too rich for me. Wandering around the store I came upon this little beauty. After haggling off the price son I walked out with it for Amir $750.
Blackhawk in .41 Mag. Had been converted by Ruger but had the original parts. So now it’s in its original form. I do love the 3-click guns.
Wonder if I could convert a Caquero to 3-click.
That’s a fine score on a .41 Blackhawk, especially with the original parts included. The three-click action has a character all its own.
A Vaquero can be converted toward the old three-screw setup, but it isn’t a simple parts swap. It generally takes the correct hammer, trigger, bolt, and fitting by someone who knows Ruger single-actions; the transfer-bar safety and related geometry are part of the job.
I’d preserve the Vaquero parts and have a qualified Ruger smith do it rather than sacrifice a good shooter to the experiment. And yes—“Caquero” sounds like the deluxe South American model.
Kilroy was here
Nice Blackhawk, i had a 44 mag one years ago. even though @Kilroy don’t like it i think it’s cool.i liked to blowed my foot off with mine shooting at a water moccasin the size of an anaconda. lol
Beltfed, I don’t hate the Blackhawk — I just don’t trust a single-action that’s already had a trigger job done on it. The .41 is a fine round, but a 44 mag with a loose screw and a water moccasin the size of an anaconda is a recipe for a foot with a new hole in it.
Kilroy was here
That’s a beauty, great share too!