The .444 is a good .30-30/35 Remington class cartridge due to the very poor bullet selection in the .429 caliber.
Poor bullets? Like these?
200g, 225g Barnes XPB
250g Nosler Partition
240g, 280g, 300g Swift A-Frame
300g Speer Uni-Cor
200g, 240g, 250g, 265g, 275g, 300g Hawk Flat Point
225g, 275g, 300g, 320g Cast Performance hardcast
180g, 200g, 240g, 300g Oregon Trail Laser-Cast hardcast
280g, 330g Jae-Bok Young LBT
240g, 250g, 260g, 265g, 280g, 290g, 300g, 325g, 330g, 335g, 355g, 405g Beartooth Bullets hardcast
Hardcast in various weights from a variety of other manufacturers – too many to list
Those are some of the very best bullet styles available for ANY cartridge. “Poor bullet selection”? I don’t think so.
Of course most people find JSP’s from Speer and Hornady and Sierra, etc, work just fine for non-dangerous game.
Factory ammo is admittedly somewhat limited but the Hornady LeverEvolution and Light Mag loads are both pretty decent loads and even standard Remington 240g JSP loads are adequate for most tasks – certainly no worse than the 240g JSPs I’ve been shooting from my .44 Mag for the last 20+ years.
Like the .450 it's almost impossible to find ammo for in backwoods locations. The .45-70 ammo is very common most everywhere because everyone loves it.
As a handloader the question of ammo availability is moot to me, as it is with many others. That said .444 ammo is as available as many other cartridges. If the availability of factory ammo everyplace they might go was a major factor in people's choice of cartridges they would have very limited choices. The funny thing is, lots of people hunt with a .444 - I guess they figured out how to overcome the ammo situation, whatever it might be.
Rather than selecting the obscure .444 or .450 I'd rather use my .30-30.
Have fun. I’m taking my .30-30 elk hunting in 3 days. Stuffed with 170g Partitions.
Interestingly, at 2192fps (Nosler 5th) the .30-30 retains only 1001fpe at 200 yards while the “useless” .444 with a 250g Nosler Partition at 2289fps (Nosler 5th again) retains 1380fpe with a virtually identical trajectory (less than 3” for both when zeroed for a maximum rise of 3”). There is no doubt in my mind which one is the better choice for elk and it isn’t the .30-30.