Older post with out a clear answer. Here it is straight from Remington's website.
https://support.remington.com/MODEL...vetail_sight_dimensions_on_the_Model_1911_R1?
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On the standard Model 1911 R1, the dovetail cut is a proprietary cut at approximately 700.
On the 1911 R1 Enhanced and 1911 R1 Carry, the the dovetail cuts are Novak style.
Novak sights can be installed on the standard Model 1911 R1 but the dovetail cuts will have to be changed. Paducah Shooters Supply and Ahlman's, two of our premier field service centers, can make the needed Novak sight cuts for the R1 for around $100. Going through our premier field service centers will not void your warranty.
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For the R1 Enhanced, order Novak cut sights .260 front/.450 rear. Personally, I'm going with the TruGlo TFO.