That's the reason I have abandoned the 44 for hunting out here in CA and taken up the old 45 Colt (well, not completely, I still love my SBH :wink: ). Those long Barnes bullets sure take up the space, but I have used both Enforcer and 296 in them. Brian Pearce has some good information on loading the XPBs in the December 2006 Handloader (no. 244) and uses enforcer, h110, 2400 and lilgun (and yes, packs only 21.5gr of H110 in there, and yes, it is a mild load but still gets 1,402 fps out of a NMBH Bisley with 5.5" barrel).
I first got some Enforcer when I started loading the Barnes XPBs and had a rough time with it at first. A lot of the data out there shows using standard primers, but the Ramshot Manual lists magnum primers as far as I can find, and in specific the Federal 155 in the 44 mag (Barnes uses WLPs). Using the mag primers really helped me get the velocities more consistent and I wound up really liking the powder and now I pick it up when I find a good deal on it. I like it in the 357 Mag also, but the 45 Colt has enough capacity that I prefer H110/296.
I like Barnes, but in the 44, I only use them specifically for hunting in CA since they are expensive and kinda weak compared to the 45 Colt loads that Pearce has in the same article. I load the 44s up with Enforcer and pack them away. Even the loads in the Barnes manual are compressed.
Like Divernhunter said, the 200 grain XPBs are nice and might be a viable option, but my main game are the larger hogs and I like having the 250gr .45 XPB load that Pearce lists in his article!
Also, here is the link to the Ramshot page:
http://www.ramshot.com/powders/
The load guide is a pdf file with a link on the left hand side of the page.
Let us know what works out for you.
ps. It's worth getting a back issue of that Handloader if you're a Ruger nut, Pearce really puts the XPBs through their paces and has an article on loading for the .44 Flattop and Mike Venturino has a great article on black powder cartridge loads, including the .44-40 and the .45 Colt. Pearce also discusses the effect chambers and throats have on accuracy, etc...