Anyone using H-110 in their loads?  I'm running 28 grains with magnum primers behind a 180 grain XTP hp.  I'm getting flattening primers but I get that with factory Winchester too.  If I drop my load below 28, then I start getting a failure to lock about every three rounds.  What say the hive?

Not using H-110 , but Accurate # 9. No issues with flattened primers, load at low to medium end of scale. Anything from 180 gr XTP, to 240 gr XTP, Mag primers, sometimes Match grade primers.  Very good reliability, very accurate.
Not sure about burn rate diff between two powders, but I have read old Mag Research data, and they used to recommend Accurate #9 , back in days when they dared to give out loading info. Also using heavy crimp, seating bullets as far in as possible
but still  able to use crimping groove. As I recall, H-110 can produce big fireballs out of barrel, I don't get much flame, even at night. Burning rate very important in this gun, as you need good power curve on burning powder to get that big slide moving correctly.

My burn chart shows Accurate #9 as being just a bit faster burning than H-110.  I have read that most say to load up toward max to get the action to cycle properly.  H-110 and Hodgdon Lil-Gun seem to be favored by many for the DE in .44.  I just wish there was more data available.

H110 is my go-to powder in the Desert Eagle in .357, .44, and .50AE.

It works great in .44 Mag with 240 and 300 gr. bullets, but I haven't tried anything lighter. The DE seems to like heavier weight bullets for the caliber.

I have always liked AA#9 as well, but AA powders always seem difficult to find locally (even before the most recent component scare).

I've only had my DE a few months and only have put a couple hundred rounds through it I've had zero problems with my load of 22.8 grains of H110 and the 240 grain Berry plated .44 HP. Nosler #7 says that it was most accurate powder and charge which is good enough for me. I've been using the Nosler manuals since they came out and they have saved me a LOT of money, time and components w/ their recommendations over the years. And I've been remiss in not publicly thanking them, so... THANK YOU NOSLER!

The load I mentioned earlier post , 19-19.6 gr Accurate #9, is on the low end as far as powder charge.
I have gone higher but both of my guns seem to cycle fine at that setting.
I know a lot of people claim you need hot loads to cycle but I have not found that to be true in my case.
My older 44 has hundreds of rounds thru it, alm ost 800, and has had new spring kit installed recently, so its still very tight.
My more recent model is brand new, had about 20 rounds thru it when I got it.
I use 180 grain thru 240 gr XTP mostly....and yes, the 180 do cycle great...I imagine they are moving pretty fast too...dont have chrony.