It's not that they won't shoot light bullets well....the stubby 245 gr Power Belt does well, but it has its own wad. A patched round ball may also work well with light charges as the patch fills the grooves at loading. As mentioned, your R.E.A.L. may do well with a wad behind it. A bare bullet though, needs enough mass to work well. There are hollow base designs also, but I don't have much experience with them in a fast twist gun.
I think most .50s now are 1 in 28". This is a list I pulled off Doug's Message Boards listing twist rates. Probably a little out dated.
RIFLE MODEL CAL. TWIST RIFLE
CVA Apollo Carbelite 50/54 1:32
CVA Apollo Shadow 50/54 1:32
CVA Apollo Shadow SS 50/54 1:32
CVA Apollo Sporter 50 1:32
CVA Bobcat Rifle 50/54 1:48
CVA Bushwacker 50 1:48
CVA Colorado MusketMag 50 1:32
CVA Eclipse 209 Mag 45/50 1:28
CVA Elipse 50 1:32
CVA Firebolt 209 UltraMag 45/50 1:32
CVA Frontier Carbine 50 1:48
CVA Frontier Hunter 50 1:32
CVA Hunterbolt 209 UltrMag 45/50 1:28
CVA Mountain Hunter 50 1:48
CVA Optima Pro 209 45/50 1:28
CVA Panther Carbine 50/54 1:32
CVA Plainsman 50 1:48
CVA St. Louis Hawken 50/54 1:48
CVA Stag Horn 209 Mag 50 1:32
CVA Stalker Carbine 50/54 1:32
CVA Stalker Rifle 50 1:32
CVA Tracker Carbine 50 1:32
CVA Trophy Carbine 50/54 1:32
CVA Woodsman 50 1:48
CVA Youth Hunter 50 1:48
Traditions Buck Hunter 50 1:32
Traditions Buck Hunter 54 1:48
Traditions Buck Hunter Pro 50 1:32
Traditions Buckskinner Carbine 50 1:48
Traditions Crockett Rifle 50 1:48
Traditions Deer Hunter 50/54 1:48
Traditions E-Bolt 209 45 1:20
Traditions E-Bolt 209 45 1:20
Traditions E-Bolt 209 50 1:28
Traditions Evolution 50 1:28
Traditions Evolution 54 1:48
Traditions Evolution LD 45 1:20
Traditions Evolution LD 50 1:28
Traditions Evolution Premier 50 1:28
Traditions Hawken Mag Rifle 50 1:48
Traditions Hawken Rifle 50 1:48
Traditions Hawken Woodsman 50/54 1:48
Traditions Lighting Lightweight 50 1:28
Traditions Lightning 45 LD 45 1:20
Traditions Lightning Bolt Action 50 1:28
Traditions Lightning Bolt Action 54 1:48
Traditions Lightning Fire Sidelock 50 1:32
Traditions Magnum Plains 50 1:32
Traditions Panther Rifle 50/54 1:48
Traditions Pioneer 50 1:32
Traditions Pursuit (All Models) 50 1:28
Traditions Thunder Bolt-Action 45 1:20
Traditions Thunder Bolt-Action 50 1:28
Traditions Thunder Magnum 50 1:32
Traditions Tracker 209 45 1:20
Traditions Tracker 209 50 1:28
Knight American Knight 50 1:28
Knight Big Horn 50 1:28
Knight DISC Elite 45 1:30
Knight DISC Elite 50 1:28
Knight DISC Extreme 45 1:30
Knight DISC Extreme 50 1:28
Knight MHS DISC Extreme 45 1:30
Knight MHS DISC Extreme 50 1:28
Knight MK85 50/54 1:28
Knight Revolution 50 1:28
Knight T-Bolt 50 1:28
Knight Wolverine 50/54 1:28
Knight Wolverine 209 50 1:28
Knight Wolverine II 50/54 1:28
Lyman Cougar Rifle 50/54 1:24
Lyman Deerstalker Rifle 50/54 1:48
Lyman Great Plains Hunter 50/54 1:32
Lyman Great Plains Rifle 50/54 1:60
Lyman Trade Rifle 50/54 1:48
Ruger 77/50 Rifle 50 1:28
T/C Woods 50 1:28
T/C Big Boar 58 1:48
T/C Black Diamond 50 1:28
T/C Black Diamond XR 45/50 1:28
T/C Black Mountain Magnum 50 1:28
T/C Encore 290x45 Magnum 45 1:20
T/C Encore 290x45 Magnum 45 1:28
T/C Encore 290x50 Magnum 50 1:28
T/C Fire Storm 50 1:48
T/C G2 (.45 cal only) Contender 209x45ML 45 1:28
T/C Hawken 50/54 1:48
T/C Impact 1:28
T/C New Englander 50/54 1:48
T/C Omega 45/50 1:28
T/C Renegade 50 1:48
T/C Scout Carbine 50/54 1:20
T/C Thunderhawk 50/54 1:38
T/C White Mountain 50/54 1:20
Savage 10ML (All Models) 50 1:24
Winchester X-150 Magnum 209 45 1:28
Winchester X-150 Magnum 209 50 1:28
Remington 700 ML/MLS Rifle 45/50/54 1:28
Winchester Apex Magnum 45/50 1:28
White .451 1:20 .504 1:24
