M14 Forum banner
1 - 9 of 9 Posts

· Registered
Joined
·
1,135 Posts
Discussion Starter · #1 ·
Greetings,

I'm like to install one of the small holo sights on my late '80s model 500, which would require a short pic-rail section. The only "sights" it currently has are a small bead at the muzzle end and a rib going longitudinally along the receiver top. Reading about the newer 500 series versions, seems they are factory drilled. Any tips for locating the holes (figure I'd use the actual rail section as a marking template) but not sure about the best area to drill into, depth of drill, etc.? The receiver seems to be pretty thin and I'm not sure how much thread I can get. Thanks in advance!

Regards, Jim
 

· Registered
Joined
·
641 Posts
You will have to drill through the receiver. As a general rule you want to have at minimum the screw diameter in thickness of the receiver metal. I have an '80s 500 too and it came d&t'd from the factory. You should have enough thickness for your rail. If its boarder line then it would be best to drill a third hole in the rail so you can get more thread contact.
 
  • Like
Reactions: budster

· Registered
Joined
·
641 Posts
Just checked to be sure , if you would rather not drill, Brownells sells a saddle mount for the 500. Easy install.
 
  • Like
Reactions: budster

· Registered
Joined
·
1,029 Posts
New BBL;

Greetings,

I'm like to install one of the small holo sights on my late '80s model 500, which would require a short pic-rail section. The only "sights" it currently has are a small bead at the muzzle end and a rib going longitudinally along the receiver top. Reading about the newer 500 series versions, seems they are factory drilled. Any tips for locating the holes (figure I'd use the actual rail section as a marking template) but not sure about the best area to drill into, depth of drill, etc.? The receiver seems to be pretty thin and I'm not sure how much thread I can get. Thanks in advance!

Regards, Jim
I have found through my experience that it is cheaper in the long run to buy a new barrel with a cantilever scope mount. I suppose the "holo sights" mount like a scope on the rail. I have mounted scopes to the receiver of a 500 and found it difficult to keep the scope sighted in. Mounted on the bbl the scope stays zeroed in. Not that old 500's are of much value but you wouldn't depleat any value with a new bbl.
 

· Registered
Joined
·
5 Posts
I was able to drill and tap my Mossberg 500 for Picatinny rail

This is how I did it.
UTG MB500T rail with screws from Amazon.
A9 aluminum tapping fluid, Amazon
Remove the barrel and receiver from the gun. Used the rail to layout the holes. The screws are M4 so I used a #28 drill bit (~3.5mm).
Using plenty of A9 I drilled the holes and removed any burring on the inside emery cloth. The cap screws have a 36 tpi (.7 metric) thread pitch so use the proper tap(4M/.7). Go slowly, use A9, and back the tap up and out and clean it as you go. I run the tap the through a second time and then run a Qtip through to clean all of the oil and debris. Use copious blue loctite and don't over tighten the screws. The rail snugs down nicely with the 4 cap screws. I'll post a follow up after more rounds but after 50 she's still tight.
 

· Registered
Joined
·
529 Posts
I had a Mesa rail put on mine and mounted a red dot. When the Zombie's attack the ones wearing "O" shirts will take a precision shot to hit the tiny brain. :)
 

· Registered
Joined
·
3,245 Posts

· Registered
Joined
·
1,001 Posts
1 - 9 of 9 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top