XS Big Dot Installation

[ChillyB]

Barrel is an 18" cylinder bore made y Mossberg for Rem 870. Tiny bead with hex base is original bead, and same thread as the bead included with the tritium sight. I'll install the bead from the kit since it seems more durable. Barrel and bead have been degreased with brake cleaner.

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[ChillyB]

Medium strength loctite 243. Pro tip: squeeze some air out before capping the tube so it doesnt leak in your toolbox when summer heat returns.

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[ChillyB]

Taped to protect the barrel while tightening with pliers. This scuffed up the bead but since I'm installing a sight over it I dont mind. It'll add extra grip.

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[ChillyB]

Loctite cures in presence of "active" metals and absence of oxygen. Steel is active, metals with copper are very active. Don't bother on stainless or aluminum, they are not active metals. Loctite sells a primer (contains copper) for those applications but you won't likely find it in local stores.

[ChillyB]

Test fitting the sight, I find it springs up when I release pressure. Looks like a little bit of plastic is in the hole, probably a vent hole from when tritium vial and plastic sleeve where cast/poured/moulded into the sight base. I'll give it a quick twirl with drill bit to remove. I dont want the sight lifting off if I momentarily release clamping pressure.

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[ChillyB]

Drill bit points to the offending plastic bit. Popped right off.

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I'd read a review that the included bead was too tall and a user had a gap under the base. I'd say he didnt screw the bead in deep enough, or had a similar plastic titty, or he had some dimensional deviation different from my set. It now sits flat against the barrel.

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[ChillyB]

Will use JB Weld. A little dab'll do ya. Mix a nice mound to get reasonably accurate ratio, be sure to use a well- mixed portion. Smooshing together with a putty knife over and over gets a good mix.

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[ChillyB]

With Q-tips handy I filled the hole in sight with epoxy, applied a light smear to concave underside of the base, and clamped. Then wiped a bit of squeezed out epoxy from the edges. Goal is to glue to bead and also to the barrel.

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[ChillyB]

Clamped, curing. The tritium sight fit close to the included bead. I recommend using that bead for that very reason.

Sight plane seems more correct than before. Big Dot is perched exactly atop the sighting channel on the receiver. With the bead I had to raise up a bit to see the bead. Later this week I'll check pattern (not that I can do much about it now).

This seems to me a good piece of sight. Gotta check fit and remove that plastic titty if your sight has one. I predict I'm going to like this sight.

And MADE IN USA! KISS MY WHOLE ASS, CHINA.

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[ChillyB]

Barely perceptible protrusion of the bead post into the bore. Brass is soft, I'll spin a brush with steel wool on a drill to knock it back. Pellets could easily knock off the whole affair if you leave any brass protruding into the bore. So don't do that.

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