Figured I'd pick the brains of those more familiar with the clip on scopes. I haven't had any luck getting consistent shifts from the daytime zero running a PVS-27 on a MARS rail. I figured there would be some shift when we got the systems, but there is not telling where it is going to shoot each time you remove and remount the PVS-27. The shift has been anywhere from .5-1.5 MOA in all different directions. Is that just something inherent with the clip on or does out mounting solution have something to do with the deviation. There is no shift running a thermal clip on, but it's about two pounds lighter than the 27. Is it too much weight for the MARS? Would the Badger EFR provide a more repeatable shift? I think the best option would be to have a dedicated night rifle, but I'm pretty sure the powers that be aren't going to spring for it. I appreciate any advice.
Night Vision Inconsistent shift with PVS-27
- Thread starter ast
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That is not something I have experienced using 27's, but i've never used one on a MARS rail.
Get a dedicated chassis that will provide you with a proper mounting solution, unless you just love your stock and refuse to run something else.
Get a dedicated chassis that will provide you with a proper mounting solution, unless you just love your stock and refuse to run something else.
Are you experiencing shift with the 27 using a chassis system? If so, how much? I may be SOL as it's a duty weapon and I don't see the admin shelling out for chassis systems. (All we've been told since we got the systems is how much they cost.) If different mounts would fix the problem it would probably be a much easier sell than chassis'. I was just curious as to other people's experience with different set ups.
Make sure the MARS rail is free floating and not touching the barrel when the PVS unit is on it. Also make sure that when you are mounting the clip on to mount it on the same footprint on the rail, make sure the mount is locked very tight and to push the clip on forward, hold it there, and then close the tension knob on the mount/rail.
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I haven't experienced any shifts with any clip on Ive used (22's, 26's, or 27) and that is being taken off at dawn and put back on at dusk, and between rifles. None of them were ran on MARS rails though. If you are having shifts, I would look to something being loose on the mounting of the rail.
Being how it is a duty rifle, I can understand there being issues getting a chassis. If it were me, I would be working on a presentation to sell the chassis to higher.
What is the rifle, stock, and optic? Was the MARS rail just installed or has it been on the rifle for a while?
Being how it is a duty rifle, I can understand there being issues getting a chassis. If it were me, I would be working on a presentation to sell the chassis to higher.
What is the rifle, stock, and optic? Was the MARS rail just installed or has it been on the rifle for a while?
The rifle is a Remington 40XS in a McMillian A5. Leupold MK 4 3.5-10x40. Mars rails have been installed since we received the rifles about a year ago. I've experienced no problems with day optic holding zero. No shift when using Flir T50, just the 27. The rifle still groups well with the PVS-27 installed, it's just a different POI from the daytime zero and it varies. I appreciate the quick responses so far.
Mount it on another gun and see if the shift replicates. Check the throw levers to make sure they are locking up tight.
Like THEGERMAN pointed out, VERY TIGHT.
Also don't rule out user error; has the shift been repeated by another shooter with the setup?
Check the thread tomorrow, I'm sure Victor or one of the other industry guys might have more insight
Like THEGERMAN pointed out, VERY TIGHT.
Also don't rule out user error; has the shift been repeated by another shooter with the setup?
Check the thread tomorrow, I'm sure Victor or one of the other industry guys might have more insight
Make sure you the loctite on the entire contact surface.
Make sure you are using the right size screw bushings and get the screws tight.
Make sure when you put the 27 on its in the same groove and be sure to push it forward in the slot when you throw the lever.
Make sure you are using the right size screw bushings and get the screws tight.
Make sure when you put the 27 on its in the same groove and be sure to push it forward in the slot when you throw the lever.
Victory--Throw levers are tight on the PVS. I haven't put that unit on another gun, but the other guy on the team is experiencing the same problem--different gun, different PVS-27. I would never rule out user error, but with the PVS on it puts them all in the same hole, just like during the day--you just don't know exactly where its gonna be. If you leave it mounted, you can dial in correction and it tracks accordingly. Take the unit off and remount it and it has shifted again.
Badgerord--installed the rail using 8-32 screws loctited with the collets exactly per McCann's instructions. Torqued to 15 in/lbs using Seekonk torque wrench--1,4,2,3 with 1 being closest to the front of the receiver. I have been putting the clip on in the same groove, but I haven't been intentionally pushing it forward. I will make sure I do that the next time I shoot.
Badgerord--installed the rail using 8-32 screws loctited with the collets exactly per McCann's instructions. Torqued to 15 in/lbs using Seekonk torque wrench--1,4,2,3 with 1 being closest to the front of the receiver. I have been putting the clip on in the same groove, but I haven't been intentionally pushing it forward. I will make sure I do that the next time I shoot.
ast, the problem is with the MARS rail and you are not the only one to have that issue running a clip on with the MARS rails. I would look at having an NVG mount inletted into your stock if the is enough material on your stock to do so. Where are you located?
Most likeley the rail,...the mounts may be true picatinny but the rail may be an approximation of the standard allowing some movement. You would be surprised just how many high end bits of raile tc are not actually correctly dimensioned as per the standardised drawing.
Uhhhggggg I didn't want to read this...
I really do not understand this. I have had zero issues with the 22 and 27 units. Terry Cross once told me that in a demo of a 27 he had the shooters hand hold the unit in front of the scope and it still did not shift to any degree IIRC. With all due respect, I think you are having some other issue causing the shift.
I'm with rth1800. Im going lean on it being an issue with the 27.
We have four guys using 22's. Two of us go 1.5 MOA low with the 22 mounted. The other two guys have zero change.
When mounting mine I've never had a change in POI, regardless of where its mounted on the rail. To make things even worse for mounting, I have a Mcmillan HTG stock that flexes pretty good with pressure on the bipod.
How old is the 27? Could there be an allignment issue with the internal components?
We have four guys using 22's. Two of us go 1.5 MOA low with the 22 mounted. The other two guys have zero change.
When mounting mine I've never had a change in POI, regardless of where its mounted on the rail. To make things even worse for mounting, I have a Mcmillan HTG stock that flexes pretty good with pressure on the bipod.
How old is the 27? Could there be an allignment issue with the internal components?
Good thing we got back to the OP in under three years !!! 
Good thing we got back to the OP in under three years !!!
Lots of frozen posts being resurrected from when she went dark. It happens
I've been a victim of that myself..............................interesting that the posts are still relevant?
