Trijicon RMR on Freedom Arms M83

[Coal Dragger]

To anyone who has experience with this combination, I am looking to put a Trijicon RMR 4.0 MOA sight on my M83 .454 Casull with a 6" bbl. I purchased the mounting base when I had the .45ACP cylinder made and the action job performed at Freedom Arms. My question is in regards to the need to shim the base to get the sight to zero properly. My mounting base did not include any shims, and as I understand it some bases do include shims.


For anyone who has used this combination will I need shims? If so does Freedom Arms make any for the RMR base?


I tried to search for the answers to this and if I missed the correct thread sorry for the trouble.

[paul105]

I have the JPoint version, which at one time was identical to the Trijicon version -- see link below.

I can't remember if any shims came with the FA mount.  I know I ordered extras from Midway at some point.

https://www.midwayusa.com/find?userSearchQuery=jp+enterprises+shims

Here's an old link on the subject sight(s).

http://www.gboreloaded.com/forums/index.php/topic,137837.0.html

FWIW,

Paul

[Coal Dragger]

Thanks for the links!


Unfortunately if I do need to shim the base it looks like the new RMR model RM01 is a different sight than the old JPoint. The new one has a forged aluminum body and the mounting base is a bit different than those shown. For example the new style sight uses only mounting bosses at the front, and the base of the sight has a rubber gasket on it to waterproof the battery area so there is no rear sight notch cut in the mounting plate.


Oh well, if I can't get it to zero, I'll call FA and see what they suggest. Maybe they make some shims.

[Coal Dragger]

Well I've now tried the RMR with some full powered .454 Casull loads, and it won't zero. Not enough downward adjustment with heavy bullets. In fact with the .45ACP cylinder installed the elevation adjustment is near the bottom to get zeroed as well.


This will need a shim, but I don't know if any are offered. Called Freedom Arms today, and was told that John (Jon... spelling?) would call me back but I didn't hear from him. I'll try again tomorrow, and see if I can get some advice or better yet a shim kit.


Aside from those issues the sight is tough, and seems to hold adjustment well even if it is in the wrong place.

[Hairy Chest]

Well I've now tried the RMR with some full powered .454 Casull loads, and it won't zero. Not enough downward adjustment with heavy bullets. In fact with the .45ACP cylinder installed the elevation adjustment is near the bottom to get zeroed as well.


This will need a shim, but I don't know if any are offered. Called Freedom Arms today, and was told that John (Jon... spelling?) would call me back but I didn't hear from him. I'll try again tomorrow, and see if I can get some advice or better yet a shim kit.


Aside from those issues the sight is tough, and seems to hold adjustment well even if it is in the wrong place.

I tried the RMR and hated it.  Too hard to find the dot.  I went back to tube sight.