I just picked up the same gun based on a friends glowing recommendation and have just read your thread with interest.
Drilling and tapping the rear sight holes is the easy part. Especially since you've already got at least one pilot hole perfectly located. The hard part is to get that front sight right. It installs over the existing bead, so you don't have to worry too much about alignment, but getting a good bond with any adhesive can be tricky unless you carefully prep the work.
I have installed both the mossberg factory ghost ring sight set and the trijicon/scattergun tech sights using Devcon, acraglass and JB weld. All of these worked well, and I have a story that illustrates this.
I was once climbing a rocky cliff and was trying to haul myself over a ledge when my shotgun slid down from by back and the front sight snagged on the rocks. I was hanging there, 10 meters or so over jagged rocks and struggling like mad to get up and over. I couldn't pull myself up and I was in a bad place. Nothing I did would free the sight and I didnt want to cut the sling and abandon the gun as I was in the back country. So I figured I'd sacrifice the sight. I flailed as hard as I could and that damn front sight would NOT break off. The sling felt like it would give before the sight would. Fearing I wouldnt have the strength left to haul myself back up, I did the only thing I could. I lowered myself down a bit, swung the shotgun back by twisting my body and then quickly hauled myself back up. It all added up to feel like the worlds hardest chinnup. But as I lay there, catching my breath and letting my cramping muscles relax, I looked at my now scuffed up shotgun. I was annoyed by the damage to the finish, but I was ultimately confident in the security of that front sight. That one was held on with a 50/50 mix of acra glass and acra gel.
Just be sure to degrease the barrel very carefully and repeat the process a couple times as oil will seep out of the metal and foul your bonding job. I used a small "C" clamp to secure the sight onto the gun while I left the adhesive to set for a couple days. That probably is a good idea too.
Does anyone know how closely the Trijicon rear sight matches the 930's contours? I also love the LPA sights, but the Trijicon ones are more in my price range.
