When I bought my first RR, it was a 6.5” model with an “M” range serial number.
I called Heritage and they said their magnum cylinder would fit. It did and works fine.
Then I found a 4.75” version and the magnum cylinder does not fit.
Last week I bought another 4.75” and the magnum cylinder does not fit this one either.
I noticed that the first one has a definite 4-click hammer. The other two, with serial numbers in the P and R series only have a 3-click hammer. They go right by the third click position and end up at the same position as my 4-click model.
Another difference is the first one simply has a serial number, the other two have a small stamped Taurus logo.
Considering that Taurus now owns Heritage I’m wondering if they thought the 3rd click might have been dangerous because you could actually pull the trigger when the cylinder was not fully rotated to the firing position. I tested mine with unloaded BB caps and even though the firing pin would make a mark on the outer edge of the BB cap rim, it would not fire.
If you have one of the newer Heritage Rough Riders with the 3-click hammer and Taurus logo you might want to contact Heritage before buying a magnum cylinder.

