All my Pietta Remingtons, both .44 & .36, came with sufficiently tall front sights, that they all fired around 5" low - some quality time with a sharp file cured the problem.
Best load for accuracy I've found for ALL my .44's has been 23-25 grains of 3F Goex or Pyrodex P.
For better fit, I'd suggest a .454" minimum ball diameter. You'll find that the .451 ball may shave a little lead off during seating, but a larger ball shaves off a bigger ring of lead. When the larger diameter ball is seated into the smaller diameter chamber, a flat is formed on the ball. It is known as the Engaging Band. The larger the ball, the wider the flat band formed on the bullet. Ball size is limited by how much force you want to expend on seating - excess force leads to wear & possible damage to both shooter & loading lever.
Once the round is fired, the ball moves forward & thru the forcing cone, which reduces the bullet diameter a little more; the Engaging Band is widened a little more & gives more surface area for the ball to engage the rifling.
For this reason, shooters with bigger balls are more likely to have better accuracy ...