OK, here's the evolution of this for me. I wanted to add more rice. Bought some 00 gel capsules from Amazon. They measure .330" on the cap, .310" on the body.
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A full case of rice in my 9mm was 8 grains weight. I zeroed the case with the empty cap on and it added 6.5grains of rice weight. SO 14.5 grains of rice vs 8.
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Here's the pattern at 2ft. Pretty danged tight.
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I still haven't perfected how to crimp/fix it into the case. I put this thru the seater die and it mashed it down enough to hold it in but I don't consider it secure. Open to ideas on that. A crimp won't work. I tried it with my .380 die and crimped it down to where the case was bottlenecked and it fell into the chamber 1/8" down---seats on the case mouth--DUH! .38spl would probably be fine.