FN 502 mini rmr o rings

[culater]

I found the solution to our problem. The mini o rings under the rmr plate are watch size O rings. The size is 3.6X1.7X0.8 ring. Unfortunately You have to buy a whole box of watch o rings to get the right size but it comes with plenty in that size if you lose them. I didn’t have any when I bought mine and the screws kept coming loose. The problem is now fixed and the screws are not backing out

Just passing on the information to pass to others.

 

[SoftCookie]

Nice. I'll have to check my 502 to see if I'm missing them. I never put an optic back on after getting it back from FN due to the recall.

 

[hlee]

Orings? I’m not removing the optic to check, but I don’t remember orings.

 

[SoftCookie]

Orings? I’m not removing the optic to check, but I don’t remember orings.

Yep. Refer to page 46 of the owners manual here:

https://fnamerica.wpenginepowered.c.../01/8.524.80.01_FN502_Manual_04.21_KW_117.pdf

They are very small so I can see why most won't notice if they fall out when changing the plates.

 

[culater]

I’m call FN to get a RMR replacement pack tomorrow. I ran my 502 hard and hit and it keep braking the post on the plate. With the o rings in it should stop that from happening again.

 

[culater]

FN is sending a rmr replacement package and the right screws for the holosun 507c. I shouldn’t have any problem from here on out.

Great gun but needs some outside support with the optic plates.