Has anyone else replaced a front sling swivel roll pin and noticed that the new roll pin fits pretty tight in the front sight base? I've recently replaced 3 of these, and 2 out of 3 fit so tight that the swivel won't move unless you twist it by hand. On all 3, the swivels are locked onto the roll pins tightly, and the swivel+roll pin rotates in the front sight base. The one swivel that flops around normally is on a Green Mountain retro barrel, while the two tight-fitters are a Colt C MP C and a Colt (non F front sight) 733 11.5 incher. I used the correct 1/8" x 7/16" roll pins, and they installed easily with no deformation. Is this just normal, or is something amiss?

I'm very likely wrong here, but I could have sworn the front sling swivel pivots on a rivet.

Not out of the ordinary. They will loosen up with use.  Quieter that way! Guessing the swivels were NOS of some sort and parkerizing a little thick. Best to lube a bit when installing pins but can still be pretty tight.

I'm very likely wrong here, but I could have sworn the front sling swivel pivots on a rivet.

Earlier originals used roll pins until 1969ish.  Later, arsenal/ field  refurbs and modern generally  use rivets.

I had the same issue, the problem was the pin was tight in the swivel itself not the fsb. I took a tiny rat tail file and  opened the swivel hole up a little and now it flops like it's supposed to.

Gotcha. Guess I've only paid attention to the 70s-and-onward models then

I thought the roll pin and swivel were supposed to lock together, and rotate in the front sight base.