I have a few Bobro QD mounts and also an ADM M4 mount on my M4s. What Im trying to accomplish is getting the Bobro mounted M4s to the same height as the ADM mount. I have been told that the Arms #74 mount could work, but have not seen or heard of anyone actually do it. Looking at the photos it looks like the channel on the bottom of the arms spacer would not fit in the Borbo mount. I like more of the true lower 1/3 co-witness and the Bobro mounts with factory spacer is closer to absolute Co-witness IMO. The pic below illustrates the height difference I’m talking about.
Thanks in advance.
Kind of the same dilemma I am going through. I had a Bobro last time I had an M4 and thought it was more of a cowitness with the factory spacer.
How do you like the ADM? Is it very robust? I have heard of people having the locking spring break on the lever, any issues? Does it return to zero???
Thanks,
John
The ADM is nice. I do like the Bobro QD mount the best, but have never had an issue over the last few years using ADM mounts. I have ADM mounts on 2 T-1’s, and their recon scope mount and then this one on the M4s. Return to zero has been right on the money. Without using a magnifier, its hard to say 100 percent certain it didn’t move 1 MOA or whatever. Ammo, and me the shooter play a bigger roll in shooting with RDS’s. I zero at 50 and have not adjusted this thing again in the last year. And the optic comes off usually every time I clean the rifle after a class, etc. So it works well IMO. Ive never broken the locking spring or have had any issue. Even if it did let go, the lever would not just come loose. I tighten mine enough so its very unpleasant or too tight to get open with your fingers and using a sling is the best way to open it. The locking tab piece is just a fail safe if something were to catch under the lever and pull it open. I wouldn’t let that be a deciding factor in weather you bought an ADM mount or not. If for some reason it did brake, the mount would still function 100 percent until you received a replacement from ADM.
What about the bobro makes you like it more? I agree the mounting lock up is stellar as I use bobro for most of my optics but the height was a little low for me. I loved the larue but don’t care much for the mounting system. If the bobro allowed another 1/8" it would be no question. This is why I am really leaning toward the ADM with the socom riser.
I guess I should have been more clear. I like the Bobro Mounting system the best across the board. I agree with you if the Bobro with aimpoint spacer was the height of the ADM or Larue, etc, that would be ideal.
I did pick up a few ARMS spacers and will be putting the base side of the spacer through the mill. Just to mill flat the part that would make it not compatible with the factory base. Should be easy to take out the center of the channel. Then it should bolt right up. I talked to Bobro yesterday, and they mentioned they had no plans to make different height spacers for the M4 mount.
I am actually considering a GDI mount. The number 7 is supposed to be a lower 1/3rd cowitness.
Yes the CM7-OSM is supposed to be lower 1/3 but I can not say first hand the exact height compared to the ADM, Bobro, etc. I cant justify the cost of the GDI mounts. For half the cost, It would hard for me to not go with the ADM. And looks like 8-10 week delivery window for the GDI. That could be a deal breaker for some…
I kind of like the idea of a single piece mount and I have one of their optic mounts on my nightforce, it is very well made. Just curious I guess mostly on sight height. I posted another question about one.
You can get them from suppliers, the 8 week is direct from gdi.
Modified the arms mount to fit the Aimpoint or Bobro base. The arms 74 mount is their 1/2 inch spacer. In the pic, the aimpoint vs arms spacers are shown. You can see the channel is not cut out and would not fit in the pictures. The ARMS raised the optic .113 inches more then the factory aimpoint spacer.
It gets it pretty close to the ADM height. Worked out fine. But for the trouble for someone starting out looking for a new mount that wasnt set on the bobro, I don’t know if I would go down this road… I wish someone offered spacers that you could bolt right up and have true lower 1/3 co-witness.
This pic is of the Factory aimpoint spacer vs ARMS spacer both on Bobro mounts.
This pic is of the ADM vs ARMS spacer on Bobro
These pics are of the spacers. Aimpoint on left. Arms on right.
Last one of the optic itself…
