I have mounted an ADM low mount/T1 on my M4 benelli. On one setting, it is VERY easy to open/close. One “side” of the bolt over, it is VERY hard to open, but pretty simple to close. It is right at my threshold of opening without resporting to a tool or straining too hard. Is this the correct setting? Also, I notice it is loosening up a bit after some use. Will this “loosening” settle and become a constant, or is something progressively stretching?
Other than this, some things I observed:
The mount is very “sturdy” looking/feeling.
Aside from what LaRue fans say, no way in hell is this a “knock-off” of a LaRue product. They both go on a 1913 rail is about all I can see between the two.
I would like to hear more feedback from others too. On 1 upper I am able to find a good setting but I have similar problem on the other upper – either really tight or a little loose. The adjustment is limited at every 1/8 turn and that extra 1/8 turn feels like to strip the thread on the cross bolt.
Also, mine initially stretched a bit but it seems to settle down after 1 year of use.
Howso? The cross-bar should contact the pic-rail nubs and stop any and all foreward movement if you have attatched it correctly (press foreward before locking). Am I missing something? This mount has a TON more “clamping” force than my LaRue mounts, and they work great.
That is something I am a bit nervous about. The threads on the cross bolt seems to be the weakest link of the clamping mechanism and I don’t want to put excessive tension on them.
I doubt anyone has broken one, because Trijicon uses a similar system on all their mounts (where the screw-threads take the force), and if the USMC can’t break something, well. It can’t be broke. I know people in the armed forces who could jack up a ball bearing with a rubber mallet in a sand-box if you left them alone with it for 30 minutes. The fact that we have not heard of these threads shearing tells me that the screw is durable, but my question is…does it stretch? With the ACOG, it doesn’t really matter as you tighten it each time. With the ADM, you set and leave it. THe lever is how it attatches/releases, independant of screw tension modification. Thus modified screw tension (due to stretching) would show up with the ADM mount and not the Trijicon style.
I don’t know, but when I have this hand tight, the red dot will drift slightly when I look at it through my open sights before and after a shooting session.
I don’t know if the POI changed as I was shooting steel targets and was not able to verify zero.
However, after this, I did tighten the locking latch and the red dot went back to where it was suppose to be without me having to make any adjustments on the aimpoint turrets.
Nothing to be “nervous” about. First, all bolts will stretch ever so slightly (yes, even LT).
Second, the lever on the ADM mount does NOT need to be ANYWHERE as tight as the LT lever as the clamping suruface is more than DOUBLE that of the LT lever.
You will find basically two position for the lever to be in. Normal tight and tool tight. The tool tight position means that you will most likely need something flat to pry the lever open. You can use this position if you like, but I personally do not think it needs to be this tight. I use the lighter setting on ALL my weapons (and yes, I use ADM mounts on all my own guns).
I have never had one break, come loose, or fail to repeat/retain zero.
By girly tight, I mean a 3 year-old has the strength to open it, if not the coordination. By Manly tight, I mean after I have got it kindof worn in I press the lock-lever with my left hand and undo the throw-lever with my right and it comes open with some effort.
As to threads stretching/distorting, etc. Here is what one of my friends has to say about the ADM mount/T1 on his Benelli M4. He uses the “Manly” setting, btw.
“I just un did the bolt and threaded it into my thread gauge, and it went in perfect. Any deformation in the threads would create considerable resistance in threading it in. Threads are perfect”
I was talking to some professional instructors about mounts and they both mentioned to me that their LT mounts have come loose (even though they were very tight). The theories for this were the following:
Bolt stretched.
Vibration of shooting and the fact that the lever is pushing in on the softer alum. allowing the the lever to keep going deeper.
The nut has backed off from the vibration of shooting.
I would like to check the bolt stretch and nut backing off theory as these seem like the main reason for it.
The above theories are what drove me to use all ADM mounts as they seem like a better mounting solution than LaRue, though I do think that the occurances of the LaRue mounts loosening up are probably few and far in-between…
I had one LaRue mount that I could almost turn the nut with my fingers on. I think the nut backing off is the most viable theory by far. It always bothered me.
