New Way To Raise Pressure

Just when you think you've seen it all, something new happens.

Situation:

• My Springfield 1903 had a high pressure load that froze the bolt during a match.
• The load is 24.5 grains Reloder #7, W-W LR primer, Schauf 30-205-SP bullet, sized 310, used linotype alloy, LBT Blue lubricant.
• The load had significantly more recoil and a huge cloud of brown-white smoke.
• Used a wooden block and two people to get the bolt open. 
• Primer disappeared and swollen head. 

Observation: During depriming one case pulled the decapping pin out of the die. The pin stuck in compressed walnut hulls stuck in the bottom of the case. This necessitated using a very thin Swiss file to get the walnut hull glob out of the die and recover the decapping pin. 

Problem?: I think this is where the problem started. This load is just over 50% case capacity, I use a light to check cases since a double charge would fill the case to the neck. Another case had a walnut hull glob, but not as deep. The decapping pin took the primer out but did not disturb the glob. When I loaded the case, there was enough glob to cause trouble, but not enough to raise the powder column to a level where it was noticeable. 

In the future, I'll check each case after cleaning to ascertain they are empty. I've simply dumped them out in the past. I'll also use a plastic rod to dipstick the powder column for uniform height after powdering. 

Your thoughts are appreciated.