Night Vision 20MOA forward rail to mount PVS-27?

[AMTeam4]

I just put together a 300WM in an AX chassis and will be doing some night shooting in the near future.
The AX chassis has accessory options of various picatinny rail attachments. They make 0MOA and 20MOA forward rails for night vision.

My question is, what is the recommended and/or standard rail cant for mounting a PVS-27? 0MOA or 20MOA
(My scope base is 20MOA if that effects the answer)

I'm very familiar with night vision optics but have never given the forward rail any thought. Previously using government issued rifles such as the M40A5, Mk11, M107, and XM3, I have no idea what the forward rail specs were regarding cant.

Any help or clarification would be appreciated.

Here are the two rails I'm referring to:
0MOA Forward Rail
20MOA Forward Rail

 

[RADcustom]

Re: 20MOA forward rail to mount PVS-27?

The Badger mounts don't have any cant however, I don't think the PVS27 is sensitive enough for it to matter. If it did cause a problem, I would remove the canted top rail and use one of the flat segments.

 

[AMTeam4]

Re: 20MOA forward rail to mount PVS-27?

Thanks for the info on the Badger IMUNS.
I wouldn't think 20MOA would make a noticeable difference but apparently AI thinks so.
I'll see how the 0MOA rail I currently have works. As long as the POI is the same I don't really care.

The cant on a forward mounting rail is definitely an interesting variable I've never considered before.

 

[RADcustom]

Re: 20MOA forward rail to mount PVS-27?

Terry Cross was telling me about some repeatability tests using a clip on unit he was present for.

Basically, attached the unit, fired some rounds and then detached it and held it suspended by hand and fired more rounds with no discernible shift in point of impact.

This would indicate that it is not critical to have it perfectly aligned.

 

[I^2 Technologies - Peter]

Re: 20 MOA forward rail to mount PVS-27?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: RADcustom</div><div class="ubbcode-body">Terry Cross was telling me about some repeatability tests using a clip on unit he was present for.

Basically, attached the unit, fired some rounds and then detached it and held it suspended by hand and fired more rounds with no discernible shift in point of impact.

This would indicate that it is not critical to have it perfectly aligned. </div></div>

I have heard this before from several sources that alignment is not critical. I have even taken a CNVD LR loose on a colimating table and been able to see in real time, the cross hairs of the rifle scope against a 100 yard target and the cross hairs never move even though the LR was wiggled just to prove this exact point.

H O W E V E R ! ! ! !

Any time you have two sets optical planes, (In this case your day optic and the Clip On) NOT in perfect alignment you are not using your equipment to the best of its abilities. The OSTI offerings with their shorter inverse afocal in the rear is less sensitive to this offset than the longer CNVD-LR. However one should strive to get both Picatinny rails parallel. In addition try and get the center line of the Clip on matched with the center of the Rifle scope. The resolution in any I^2 tube is best in the center. If you have to buy new rings and a Cheek piece, it is my recommendation to do so in order to get things as lined up as possible! Stack the deck in your favor. Shooting at night has a whole host of things that aren't optimal, why add one more that is correctable? Hey if your buying something that expensive why not make it operate at its optimum? It's like buying a Ferrari and running cheap tires.

IPSC_GUY
SIERRA II ALPHA

 

[AMTeam4]

Re: 20 MOA forward rail to mount PVS-27?

So what's your opinion then on the forward rail cant IPSC_GUY?
If you have a scope mounted on a 20MOA base, do you personally mount your clip-on night vision to a 20MOA forward rail?

The lack of POI shift with Terry’s range testing is pretty cool.

 

[I^2 Technologies - Peter]

Re: 20 MOA forward rail to mount PVS-27?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: AMTeam4</div><div class="ubbcode-body">So what's your opinion then on the forward rail cant IPSC_GUY?
If you have a scope mounted on a 20MOA base, do you personally mount your clip-on night vision to a 20MOA forward rail?

The lack of POI shift with Terry’s range testing is pretty cool.

</div></div>

I use a LONG PRI rail that puts the Clip On, on the same plane cant wise as the optic. In your case with the ability to select a 20 MOA front cant to match your 20 MOA base I would absolutely go with the 20MOA front rail.

IPSC_GUY
SIERRA II ALPHA

 

[AMTeam4]

Re: 20 MOA forward rail to mount PVS-27?

Thanks for the feedback guys.
I'll be stuck using the 0MOA forward rail until I can find a 20MOA rail that's in stock. When I find one I will compare what my groups look like with both at distance.
A noticeable difference, if there is any, should be easily seen at 600yds.

 

[sandwalk3r]

Re: 20 MOA forward rail to mount PVS-27?

I am also interested in this general topic.

I'm trying to sell some things to either buy a new and better rifle than my normal R700 or have a lot of work done on it to make it sub-1/2MOA.

I am in the process of selling a lot of stuff, and I'm hoping to be able to pick up one of the new TNVC clip-on sights once they are released.

I am currently running the AX chassis, and the fore end doesn't exactly line up flush with the base rail on top of the action. This is one minus for this chassis in my book if you're looking for a clip-on. Not that there isn't a good way.

That's why I'm thinking either a CADEX chassis and rebuild my R700 on that or get a DTA SRS. Both have the rough equivalent of a one-piece rail, which is great.