New front sight too loose in dovetail

[shootist26]

Just got a new set of Truglo rifle night sights for my 870 Police. The front sight is way too loose in the factory dovetail and I can slide it in and out with finger pressure. What's the remedy here?

[41magfan]

Support the sight base between the jaws of a vice and use a hard, sharp punch to raise dimples on the bottom the sight. How many and how deep will depend on how loose it is in the dovetail. Lastly, use something like green Loctite 620 and you should be GTG.

[willie]

Support the sight base between the jaws of a vice and use a hard, sharp punch to raise dimples on the bottom the sight. How many and how deep will depend on how loose it is in the dovetail. Lastly, use something like green Loctite 620 and you should be GTG.

Is the base permanently attached to the barrel? If so, holding the base in a vise might be awkward, especially if it's sides are contoured. Sight companies hear this complaint fairly often. I suggest contacting the company. Their sight and not the base may be out of spec.

I'm surmising which sounds better than guessing. I claim no special knowledge.

[41magfan]

Is the base permanently attached to the barrel? If so, holding the base in a vise might be awkward, especially if it's sides are contoured. Sight companies hear this complaint fairly often. I suggest contacting the company. Their sight and not the base may be out of spec.

I'm surmising which sounds better than guessing. I claim no special knowledge.

After reading your post, I realized that I worded mine poorly. Supporting the "base" of the sight blade between the jaws of a vice is what I meant to convey. Thanks for catching my confusing verbiage.


https://imagizer.imageshack.com/v2/640x480q90/922/IpzIih.jpg (https://imageshack.com/i/pmIpzIihj)

[shootist26]

After reading your post, I realized that I worded mine poorly. Supporting the "base" of the sight blade between the jaws of a vice is what I meant to convey. Thanks for catching my confusing verbiage.


https://imagizer.imageshack.com/v2/640x480q90/922/IpzIih.jpg (https://imageshack.com/i/pmIpzIihj)

That's what I understand your initial post to mean. Thanks

I'm having a hard time visualizing what the punch is doing. I see a small dent being made in the base. How does that tighten up the fit between the sight and dovetail?

[41magfan]

That's what I understand your initial post to mean. Thanks

I'm having a hard time visualizing what the punch is doing. I see a small dent being made in the base. How does that tighten up the fit between the sight and dovetail?

The above pic was just to illustrate the support needed to keep from bending the base when you start striking it with the punch. The marks on that sight are irrelevant to this discussion.

When you strike the bottom of the sight with a sharp, pointed punch it will cause a "crater" to form with a raised edge. The deeper the punch goes, the more material it will "raise". These raised dimples/edges will simply cause there to be some interference in the clearance between the sight and the dovetail.

Most sights are made of metal soft enough to readily "dimple", but occasionally you will run across hardened steel that will require a VERY hard and VERY sharp punch.

ETA: After a bit of contemplation, I wouldn't bother with the dimpling method for this application - I'd simply use an appropriate epoxy product.

[willie]

The above pic was just to illustrate the support needed to keep from bending the base when you start striking it with the punch. The marks on that sight are irrelevant to this discussion.

When you strike the bottom of the sight with a sharp, pointed punch it will cause a "crater" to form with a raised edge. The deeper the punch goes, the more material it will "raise". These raised dimples/edges will simply cause there to be some interference in the clearance between the sight and the dovetail.

Most sights are made of metal soft enough to readily "dimple", but occasionally you will run across hardened steel that will require a VERY hard and VERY sharp punch.

ETA: After a bit of contemplation, I wouldn't bother with the dimpling method for this application - I'd simply use an appropriate epoxy product.

In night sights, the tritium is encapsulated within a fragile capsule. Striking the sight's metal body with a punch or other tool can fracture this capsule. For this reason one must take care when moving the sight laterally. Instead of using a punch to roughen the base's bottom prior to using adhesive, I suggest using a file or even a hacksaw.