I recently shaved down the front sight base on my LMT carbine barrel for use under a PRI rifle length tube.  When I removed the original pins from the FSB, I noticed that they were straight and not tapered.  I was thinking about replacing the original pins with roll pins to make it easier to remove the FSB in the future.

Since the shaved FSB will be under the PRI tube, is there any reason I should not use roll pins?

I would suggest using your original pins, as long as the fit is still tight enough to secure your fsb ther is really no reason to change pins. Roll pins are not as easy to drive in as a conventional dowel pin. The roll pin is made larger than the hole it is intended to go into, and therefore must be compressed while it is driven into the hole.   Hope this helps, PATRIOT ARMORY 07 FFL