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View Full Version : **URGENT** Need info on a potentially dangerous front sight install


inSight-NEO
March 5, 2009, 08:46 PM
I just received a Meprolight front bead sight for my Mossy 590 and noticed, upon installation, that the final thread is protruding (slightly) into the bore. I also noticed that the stock bead sight (via Mossberg) slightly protruded into the bore as well. Im hoping that since the stock Mossberg bead "penetrates" the bore somewhat slightly, that the Meprolight sight will be just fine. So, is this normal and much more importantly, safe?

It seems to me that, in both cases, the metal is fairly soft. Therefore, Im hoping that after several boxes of 00-buck, the residual threading will essentially be "blown" out. Is this wishful thinking?

I spent $30 on this thing and if it needs to be shortened (its already quite short), I frankly have no idea how I can do this myself without damaging the threads. Any help would be appreciated.

colostomyclown
March 5, 2009, 08:56 PM
Can you link to the sight you purchased? Unfortunately i can't answer your question but the bead on my 590 is pretty much as you descri ed, if it's any consolation.

inSight-NEO
March 5, 2009, 09:09 PM
Can you link to the sight you purchased?


Here is the link: http://www.topgunsupply.com/meprolight-tritium-bead-sight-shotgun-5-40.html

The SKU is: ML34044

As I mentioned before, I have noticed that the stock Mossberg brass bead sight protrudes into the bore as well. Im guessing then, that it may not be a dangerous matter...I just dont know. Im used to GR sights with welded posts, so this threaded stuff is new to me.

flippycat
March 5, 2009, 09:15 PM
as per this thread it looks like it is common for a thread to run through ...

LIProgun
Senior Member

Join Date: 2000-08-27
Location: Long Island, NY
Posts: 491

If you just want a tritium front bead, the Meprolight unit is good. I have installed a few of these in the last year. All it requires is the proper numbered drill bit and a tap. After the unit is screwed in (and Loctited) you can remove the threads that protrude into the barrel with a cratex wheel on a Dremel, if you like.

On one of the units I painted a white outline around the tritium dot for better visibility in daylight.

If you want ghost rings, go for the permanent installation of the front ramp (via brazing, IIRC) like Gunsite does. I think they use MMC sights. You could do worse than sending your gun out to Ted Yost at Gunsite to do the job.

https://www.thefiringline.com/forums/showthread.php?p=117578


if you did not have a dremel you could always fine file the threads to remove the extra prior to installing and straighten the catch thread if needed with a razor or in most cases just a stiff fine wire brush then screw in as normal. As long as you hold it straight to the file you should not butcher the thread to where they will not screw in.

inSight-NEO
March 5, 2009, 09:36 PM
if you did not have a dremel you could always fine file the threads to remove the extra prior to installing and straighten the catch thread if needed with a razor or in most cases just a stiff fine wire brush then screw in as normal. As long as you hold it straight to the file you should not butcher the thread to where they will not screw in.

I may give this a try. Now, if Im just too leary of attempting this, in your opinion, would leaving the excess be "safe?" Im not great with measurements, but it seems like we are looking at roughly 1/48th of an inch (or less) of excess metal; basically one thread, give or take. It seems as if, based on the quote you listed, removing any excess is optional but not necessary.

Also, given that the threads seem rather "soft," Im thinking that they may "naturally" smooth out after repetetive exposure to friction/heat associated with firing. Maybe this is just wishful thinking......

colostomyclown
March 5, 2009, 09:50 PM
i'd calla gunsmith locally that you trust and ask if no one can give a definitive answer here. in any event i'm excited to see what happens because that is a nice bead sight and i'm interested in adding one to my 590 now. is the sight pretty sturdy in your opinion? how's the glow?

inSight-NEO
March 5, 2009, 10:09 PM
is the sight pretty sturdy in your opinion? how's the glow?

It seems sturdy to me. In terms of the illumination, it seems to be up to par. I have night sights on my Sig (for comparison) and it seems to me that the Meprolight offers roughly the same illumination (glow), although not quite as much. Still, Im satisfied as it certainly beats having absolutely nothing to see up front (in the dark).

colostomyclown
March 5, 2009, 10:14 PM
nice sight. i'm pretty sure they're one of the only companies that make a nightsight front bead. I'm thinking about adding one, but I'm going to have a light anyway so I'm not sure.

flippycat
March 5, 2009, 10:17 PM
inSight-NEO

I may give this a try. Now, if Im just too leary of attempting this, in your opinion, would leaving the excess be "safe?" Im not great with measurements, but it seems like we are looking at roughly 1/48th of an inch (or less) of excess metal; basically one thread, give or take. It seems as if, based on the quote you listed, removing any excess is optional but not necessary.

Also, given that the threads seem rather "soft," Im thinking that they may "naturally" smooth out after repetetive exposure to friction/heat associated with firing. Maybe this is just wishful thinking......


I could only offer an opinion on "safe" anything ..there are far more knowledgeable members here then myself though I am not sure if anyone would actually give you a safe answer without actually seeing it in person. Though my advise on shortening that screw is solid :P I have modified many a screw to fit my needs over time and found not much works better on a small screw then a fine file or even a decent piece of sand paper depending on the grade of bolt.

Scattergun Bob
March 5, 2009, 11:01 PM
In my tenure of being a armorer and keeping in-service hundreds of scatterguns, changing and replacing front bead sights was a weekly occurrence. Even the factory replacement sights from Remington required some "fitting" and a cutting file " gently" applied.

It is not uncommon to have Too Long a thread length for a skinny barrel, back out the sight, file a little, making sure not to damage the existing threads and re fit the sight. That would be the safe thing to do.

Please remember that there is more to gunsmithing than simply replacing parts!;)

Good Luck & Be Safe

MAX100
March 6, 2009, 07:08 PM
It is simple and straight forward and very easy to do.

Use a fine file and file the screw down. Use blue loctite after you have it right. Screw the sight all the way on and line the sight up straight with the barrel even if you have loosen it a little, let the loctite dry. The loctite will hold it.

Degrease the screw and hole before applying loctite.


GC