Well, it looks like the front sight mounts directly to the barrel using solder, or maybe epoxy. You'll probably either have to sweat the bead's pedestal off, or mount the new sight in front of it. Might need to be a gunsmith job.
What's the exact sight set you bought, though? Do you have a product name or a manufacturer code so I can make sure I'm looking at the right thing? I've never worked with these sights before, so this is mostly conjecture.
Old conversation, but I've taken a slightly different approach. I picked up a set up of LPA sights...a BAR11W rear sight and an SG4 front sight. The read sight attaches to a picatinny rail section that you need to drill/tap to add, and the front sight is silver soldered in place of the post/platform/BB.
My 1100 is set up with the same rig. I've been shooting the 1100 for 10 years and after I zeroed it in, it's been flawless and deadly accurate. I regularly group slugs at ~5" at 50 yds (over a bag)
Note, you can buy interchangeable ghost rings and swap them around. Same with the front sight.
Some may consider the front sight "tower" a snag hazard. No concern here..
Before you order, I would HIGHLY recommend you put in a call to LPA to get the right combo based on/where you mount and what weapon you mount it to. Height is critical! In other words, if you don't get the right mounting combo, the sights will be useless.
