Protruding shotgun sight

D

Dave R

New member
Just got an old Brazilian 20ga for my kids. The threads of the screw-in front bead protrude slightly into the barrel. Can I just sand the protrusion off in place? I mean, wrap some fine sandpaper around a dowel and file that smooth to the barrel? I figure a gap may be as bad as a protrusion, and this way, I'll wind up with a smooth surface.

Or will I damage some finish on the barrel with sandpaper marks?
 
You can use sandpaper on a dowel to cut the sight shaft flush, but you will leave scratches in the bore. The proper tool for removing the scratches is a two-stone brake cylinder hone with a liberal dose of honing oil applied to the hones. You spin the hone with an electric drill motor. Overly enthusiastic honing will open the choke up a thousandth or two, so be judicious (unless you want the choke opened up, which might be a good thing for a kids' gun). Brownells sells the hone (www.brownells.com).
 
Excuse me Clemson, but the proper method would be to REMOVE the sight and FILE it down. Reinstall it and check to see if it's still protruding. IF it is, continue filing (slowly, small amounts) until it no longer protrudes into the barrel. Once it's where you want it to be, reinstall it with RED LOCKTITE.

You will have just PROPERLY fixed this problem. With no effect to the interior of the barrel.
 
This question only applies to plain barrels (i.e., non-vent rib barrels) with fixed chokes -- in other words, hunting guns. I have always just ground the threads with a dowel and abrasive paper and then honed the barrel. The few times that I have tried to pull the bead and grind the threads, I found that I tended to take too much meat off.
 
Thanks, folks. I did remove the sight and file a bit off, first. The result was that it was real tricky to get the bead threaded back in, without a tap (?) die (?)to clean up the threads.

Also concerned about getting the threaded area too short. I think a pit would be as bad as a protrusion, in disrupting the shot column.

That's why I wanted to do it in place. Perfect surface. I appreciate the suggestion about the hone. Sounds like the best way to do it.

And with a $70 gun, I'm not terribly concerned about a mirror finish. I was more concerned about whether scratching a finish would promote more rapid corrosion or rust.
 
Clemson was correct

When I trim screws, I drill and tap a hole in some scrap steel then trim the screw while it's installed in the hole. That way, you clean up the threads some when you remove the screw. Unfortunately, this will not work too well on a shotgun barrel. You will have to trim it with the dowel like Clemson suggested and then clean up the scratches with a hone. The reason is that you will be unable to properly allign the concave cut when you reinstall the sight. Many sights are made of brass so that they trim easier than the steel and prevent damage to the barrel. I'd just leave the scratches in there if it were me. Doesn't sound as if the gun is worth too much. If it is, have a gunsmith do the work. Shouldn't cost more than $10 or $15 bucks.
 
FWIW, many high grade shotguns come with the front bead sticking into the barrel. Unless it is really sticking down, don't worry about it; there is no effect on the pattern. I would not use a brake hone on a shotgun barrel.

There is a tool to remove and hold the bead while trimming the shaft, but not worth buying for one job.

Jim
 
Just thinking out loud here, but if we clean the barrel from the breech so as not to ruin the crown with mere cleaning rod friction, doesn't it stand to reason that sanding the barrel lining at the muzzle could destroy the barrel? Jez curious...
 
Romulus, my limited understanding leads me to believe that is important for a rifled barrel, but not so much for a smoothbore. As long as the barrel is round and not pear-shaped, I don't think removing a thousandth will affect accuracy. It will just open th choke a bit, as others indicated.

If anyone knows better, chime in.
 
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