If it doesn't have to be jacketed you might take a look at the offerings from Badman Bullets in 44. From their website:
"Badman Polymer Coated Bullets have a strong lead core (15 BHN) with a durable 2 layer baked on Polymer coating finish. They perform extremely well from low to high velocities. We have personally tested our .452 diameter 250 Grain RNFP bullet to 1,800 fps with great results. Compared to plated or jacketed bullets they are less expensive, as good as or better and they don't foul your barrel."

They are quite low on inventory at the moment. You will find good info from them too if you call.
Karl