Tallboy Posted October 24, 2022 Author Share Posted October 24, 2022 I did find this which answers my question... very interesting if anyone else is wondering. I know 110 isn't used in any reloading here likely, but it's still very interesting to me Quote 4. The primary reason for "DO NOT REDUCE" warnings for H-110 or W-296 is SQUIBS and here's why: These powders tend to burn in a "serial" manner, which means the primer flash will ignite the first layer of powder kernels and in turn, those kernels ignite the next layer of kernels, which ignite the next layer until all powder is finally ignited. This works exactly like a fuse where any air gap or void between kernels will cause ignition to cease ... or at least stall until other touching kernels ignite it. A stall results in multiple pressure peaks .... not good for accuracy but not specifically dangerous. If powder ceases to light up the next layer of kernels .... basically the fire goes out ... just like a cut fuse and you end up with a squib where the bullet gets stuck in the bore. Squibs happen way more in colder weather and almost always at initial ignition. 5. How can a reduced charge increase chamber pressure? Here's how: Let's assume a typical water bottle represents a cartridge where the end with the bottle cap is the primer and the water represents the powder. If the water bottle is nearly full, water will collect at the primer end and will ignite in a "serial" manner. Lay a half full water bottle flat horizontally and look at it. A much larger area of water surface is now exposed to the primer flash. This can cause the powder to ignite in a parallel manner, which will raise chamber pressures to very high levels. In other words, it turns a slow burning powder into a very fast burning powder and increases chamber pressure dramatically. The safe standard to prevent excess pressure and prevent squibs is to load to at least 75% of case capacity .... 80% is better. Link to comment Share on other sites More sharing options...
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