There wasn't a huge difference with the 'crud ring' after I went with the 25ACP conversion in my Encore. It was there and managable before, and its about the same after. It was a little less than it was when owned a Huntsman and used the 209 with loose Pyrodex.
The reason that I made the conversion was to reduce the affect of the 209 primer on the load that I use. The powerbelts go into the barrel easily as do the Pyrodex pellets. The 209 primer is powerfull enough to push the load up the barrel prior to the ignition of the majority of the powder. Especially in a clean barrel. My presumption is that this affect caused the first shot flier that I was getting out of a clean barrel.
With the 25ACP conversion, I no longer get a first shot flier. Nor do i get any blow back. I use the decapper tool from an old .223 Lee Loader to decap the used shells and after cleaning with soap & water, I prime the shells using the Lee AutoPrime tool.
I'd be curious as to whether or not there will be a hex head on the Huntsman 25ACP BP. I'd bet they'll adapt the existing Huntsman BP for the 25ACP shell as they did for the Encore??