IMR 4831 in .223 Rem

[mikeAB]

IMR 4831 in .223 Rem

On advice from a truly trusted source I will contact Hodgdon and ask their opinion on using IMR 4831 in a .223 Rem.
That source said...
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As I mentioned at the range, there have been accounts of chamber ringing when very slow powder is used in reduced loads.
The problem seems to have been traced to double detonation. And yes, fillers like DACRON have been involved.

Personally, I'd stay away from using 4831 in the .223. Why use it when there are so many appropriate powders available for that cartridge?

You might want to contact the powder manufacturer to get their take on the issue. I'd be very surprise if they would give you the
green light to continue using 4831 in the .223.
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[Unclenick]

He is correct except about the detonation. The problem is the powder can get the bullet moving faster than such a slow powder evolves gas in the early stages of its progressive burning. This drops pressure and the powder is then further delayed in building pressure. But once it does start to build the pressure it propels its own mass down the tube and that slams into the bullet which is not going very fast at that point. That sudden pressure jump from the impact of the gas mass causes the pressure spike that rings the barrel.

There is a description of an AR ringed by this is the second half of this article under Secondary Pressures. It also shows how a strain gauge pressure system can see the echo of the pressure bump when it happens. In general, using a powder too slow for a bullet sectional density is a bad idea.