[The_Watcher]

I have an HK imported M1S90 with rifle sights on which I would love to install an aim point micro.

My question is this, will doing so hurt the value of the shotgun? Is it a shotgun that will appreciate in value without the Modification ? Should I use this as an excuse to buy a different shotgun for my rds?

To install the rds I will need to drill and tap(a pro gunsmith, not me) 2 holes on top of the receiver and install a picatinny rail

 

[Schlafftablett]

Depends on the vintage of your M1S90 really. If it's a run of the mill standard production gun then drill away. If it's a very early gun with only the HK markings on it or a LNIB example then you may want to reconsider. It seems that most of the M1's have reached a plateau of late because of the desire for the M4's but there doesn't seem to be much swing between bottom and top dollar for the older guns. I have been seeing them selling for between $7-900 regularly with the occasional $500 or $1200 but those are really the exception. That said you could always go with a no-drill mount.

 

[The_Watcher]

Thanks for the insight. Mine is a run of the mill M1S90 and I really have zero interest in selling. So I will probably drill and tap.

 

[bordercop]

Really, it's up to you. There are mounts that can be mounted without drilling and tapping. They usually wrap around the receiver and are held in place with a screw that goes through in place of the trigger group pin.
.
I've never tried the rail mount, but my side saddle with similar mounting system feels solid enough.

 

[Schlafftablett]

I have a mount similar to the one pictured that I'd sell you for like $20 shipped if you wanted to try it out. Did you have a screw on mount in mind or were you looking to have one fabricated?

 

[The_Watcher]

I was thinking Mesa tactical combined pic rail and side saddle.

 

[pb_removed]

I was thinking Mesa tactical combined pic rail and side saddle.

I could be wrong, but I believe those are for Benelli models that are already drilled and tapped for the picatinny rail (M4) and the side saddle is attached to the rail. I don't think there is any offering for Benelli where the mount is free floating off of the side saddle mounted to the side of the receiver.

 

[The_Watcher]

I could be wrong, but I believe those are for Benelli models that are already drilled and tapped for the picatinny rail (M4) and the side saddle is attached to the rail. I don't think there is any offering for Benelli where the mount is free floating off of the side saddle mounted to the side of the receiver.

You are correct, it is made for the M2. Mesa said just drill holes in same spot as the M2, on the M1 and it will work.

 

[Schlafftablett]

I can drill it for you if you don't already have some one in mind.

 

[JTinIN]

Check the archives, but there is a possible reliability issue with recoil operated shotguns if you ad too much weight (i.e. ammo and optics) .... or at least that was part of the story with the transition to a gas system.

 

[The_Watcher]

Check the archives, but there is a possible reliability issue with recoil operated shotguns if you ad too much weight (i.e. ammo and optics) .... or at least that was part of the story with the transition to a gas system.

I have heard that as well. The reason I am going for it is because it will only add 4 shells, the mount, screws, and the aim point micro. Sight weighs 3.7oz, mount weighs 7oz, screws are negligible as I will remove material that the screws will occupy, finally the ammo. I will weigh that when I get home. I know the lower recoil stuff will not cycle, but I will test with full power loads as that is what will be in/ on the gun.

 

[The_Watcher]

I can drill it for you if you don't already have some one in mind.

Where are you located?