The most accuracy gain in a 1911 pistol is a good barrel and good barrel fit.
As was taugh to me by my Mentor in 1969 the barrel needs to be hard fit, that was the terminology he used.
He went on to explain to me that for a barrel to be hard fit it needs to lock up at both ends like a bank vault.
So you need to keep tolerances at both ends to a minimum.
Do not use a barrel or bushing that is a drop in fit if you want the most accuracy gain.
I've hard fit barrels, lathe turned and angle bored the bushings, the guns I put them in would shoot less then 1 inch groups at 25 yards.
So using the standard rule of thumb the group size will double at 50 yards, so the gun will shoot less then 2 inches at 50 yards.
There's a lot of accuracy modifications some will try and sell you on.
When one does the math dealing with the tolerances of the 1911 its easy to see the accuracy gain by doing those modifications is so small that very few if any shooters could take advantage of it.