I have replaced one part on the Colt Series 70 Government
Model I paid $235.00 for in 1971. I removed the "collet"
barrel bushing and replaced it with an Ed Brown "drop-in"
The collet bushing had never failed, but some respected
"smiths" had warned me that if it ever broke, I might destroy the
slide just getting it off. So I replaced it.
I can't say it helped the accuracy, but it didn't hurt it, either. And
I feel better about the dependability of the gun.