Bituminous and anthracite are different coals.. the first post is about burning bituminous coal, not anthracite..
The facts are that Harman, Keystoker, Hitzer, Russo, Gibraltar etc hand feed stoves use a full grate with vertical firebrick sides,, this is not an accident.. it would be much cheaper to build a Tapered 'V' firebox with a smaller grate.. BUT this does not work well with coal. Any coal. You can get anthracite to burn in this design, but it is still a compromise.. do a search for US stove on the site,, you will find many people with frustrating experiences with this poor firebox design.
I'm glad you are happy with your Ashley, but you are a rarity being happy with that design.. Once a person sees that you can load a [mad to burn coal] deep firebox instead of spread-out shallow bed of coal [in a mde for wood] firebox,, and end up using the same amount of coal to burn twice as long with a deep coal bed,, then they understand..And the fire is reliable and consistant.
If I were to build a new hand feed boiler,, I would have a 20"x20"x 18" deep,, yep 18" deep firebox.. it would burn for 18-24 hours on one loading, and with full shaker grates underneath would not clinker or require cleaning more than once a season. Providing I don't feed it rocks or shale.
Take a look at the Harman, Keystoker, Hitzer sites.. all of their stoves and hand feed boilers are of this design, and are flawless burning coal stoves, and they fit my description.
I made a huge mistake when I copied the US Stove, and other's firebox design with the 'V' shaped narrow grate firebox.. good for wood, marginal for anthracite, a disaster for Bituminous.