Unknown residue with W231

Not used to this powder.  Used it for the first today.
Load is light by my chronograph (too light?)

What are these light straw-colored granules (about the size of coarse salt) left in my action?  After forty rounds, there had accumulated enough to be very noticeable; it looked, other than color, like maybe half of a brass case full was dumped in the action to give you a sense for how much was there.  Based on color I'm pretty sure it is not unburnt powder. 
If it is just a byproduct of combustion, was my load too light to eject this mess?  It was unusually light for me, ringing up at just over 700 ft/sec.  Is this powder cleaner at higher pressures maybe?
Ed

My first guess would be incomplete combustion from not making enough pressure.

it seams to me that was why I quit using it, I did have better results heaver charges

You didn't say what your load was but folks are right, it's hard to light.

Sounds like too light of a charge, I seem to recall w231 gets extra filthy under 4.7 gn. 
VV320 does the same thing under 3.0 when I was running that powder with 105gn swc cowboy loads, it was an experiment.

I have only only been shooting outside this year.  I have been using the same load of 3.7- 4.0 gr N310 with a 185 LSWC bullet.

I did not notice any particles over the summer or early fall.  But, when I was shooting when the temperatures fell into the 30's I would see a few particles that were very similar to what was described in the first post.  At first I thought I did not get all the walnut shells out of a few cases.  So I purchased a Franklin Armory water tumbler.  But that did not eliminate the particles.  

 A week ago I was shooting when the temperature was 20-25F.  I don't think I could fill a case.  But, they were on the brass catcher base, around the ejection port and even a few in the trigger holes.

Other posts have described N310 as being temperature sensitive.  I am starting to think it is not all burning.  I have some Bullseye, Titegroup, Clays, and WST.  Does anyone know if any of those perform in the cold.

SonOfSwede wrote:Other posts have described N310 as being temperature sensitive.  I am starting to think it is not all burning.  I have some Bullseye, Titegroup, Clays, and WST.  Does anyone know if any of those perform in the cold.

Hello SonOfSwede,

Bullseye....hot, cold, in between....it's always the same.  It's my go to powder.

CLAYS....pretty much the same.

Jim

I had a lot of what looked like the same particles in my 45 when I started to shoot in colder weather.

The last 2 trips to the range I increased my load of N-310 by 0.2 gr and kept my magazines warm until I was ready to shoot them.  At the club I belong to we can drive to the firing line.  So, I left the engine running and the loaded magazines sitting on the heated seats until I was ready for them.

Two range trips with temps in the 20's, each with 100 rounds resulted in no straw colored particles.  I think the people who said the particles were unburned power were right on.

STEVE SAMELAK wrote:My first guess would be incomplete combustion from not making enough pressure.

I would agree they are unburnt powder particles, but I am unsure they are necessarily due to not enough pressure. Combustion of powder is inefficient, ways to increase efficiency is by raising pressures and combustion temperatures. But I have always had unburnt powder particles, even with 357 Magnums. I turn the revolvers muzzle up, dump the brass right into a plastic bucket or tray, after firing. That tray always has powder particles when the brass is scooped out.

The 45 ACP is a relatively low pressure cartridge, I would recommend trying Bullseye Pistol powder or Titegroup if the residue bothers you. Those powders have a sharper pressure rise and I get less unburnt powder with them. Though, I gotta say, a 230 FMj with 5.5 grs of W231 is an outstanding load, and I can down load W231 and still get excellent accuracy.