Squibs, clumped powder

[FROGO207]

Taking the propellant out of the refridge and using it without a warm up period *might* induce some moisture in some rounds as they are assembled especially if it was humid at the time. Just like that glass of ice water set on the counter for a bit before consuming. I am thinking this. I have taken apart shotgun ammo that had clumped propellant to reclaim components. It had been left in a 5 gallon bucket that had partly filled with water some months previous. Then left in the hot sun for 3 weeks to dry it out by the time I got it. The hulls were all corroded on the outside. I put ALL the components in a fresh hull (cut the crimp off the old one, broke the clumped propellant up) and tried them, all shot OK. Ended up making 300+ reclaimed skeet rounds of 20 GA out of them and all shot just fine. So propellant contamination or small amount in some rounds of it are my best thoughts of your problem.

 

[badkarmamib]

I don't know how old your powder is but this is only happens when it's not stored properly or due to old age (my case).

Powder had been bought at LGS that is known for quick restocking the previous week. Haven't checked lot number, but seems unlikely.