I have a Shires 25/47 slide with two small shank lead pipes. One is a M 1.5, and the other is marked M 1.5 R. The R is about an inch shorter than the 1.5. Can anyone tell me what the R denotes, and what the playing characteristics of the shorter pipe might be?

Are they both yellow brass? The R could stand for red brass, although I’m not sure I’ve ever seen a Shires re brass pipe. I actually had a gold brass 1.5 pipe made at one point but I can’t now remember if it was marked with a ‘G’. Interestingly, it was also around an inch or so shorter than my standard yellow brass 1.5, even though I was assured it would be ‘the same leadpipe but in gold brass’.

In any case, a shorter leadpipe might feel more open or less stable, or as having a ‘wider’ sound (you might feel this as the notes having wider slots or being a little easier to move between partials), and a longer pipe could feel more focused or locked in, with tighter slotting and more stability, and ability to hold together at higher dynamics.