Side Mounted WMLRF

[DogDown338]

Hello everyone. Brand new to WMLRF,
I’m looking at the vortex and new tango wmlrf’s and am just curious why I don’t see them side mounted anywhere. I run a Seeking SP10M in 6.5 and Seekins told me the rail is rigid enough for it, also contacted vortex about zeroing the system from a side mount. They said it was no problem as long as the rail was stiff enough.

I love running a 12 oclock red dot over my optic (March 4.5-28). So in theory, if I zeroed the red dot at 100 yards and the wmlrf, i would never have to dial back to zero between shots before ranging. Could simply put my red dot on target and tap my range button. Am I missing something. Please educate me.

 

[Gentleman4561]

Biggest reason I don’t like side mount is that it’s more likely to be obscured from various shooting positions.

I also don’t believe for a minute that any handguard is going to be as solid as a scope mount.

 

[Trigger Monkey]

How are you making sure that you're putting the 2 MOA dot with no magnification on the thing you want to get a range to? It seems like it wouldn't take much to dip off the edge or completely miss the object and get a false measurement.

 

[Zak Smith]

I use the Vortex side-mounted on several guns and it works great.

 

[DogDown338]

How are you making sure that you're putting the 2 MOA dot with no magnification on the thing you want to get a range to? It seems like it wouldn't take much to dip off the edge or completely miss the object and get a false measurement.

True. I suppose some sort of vulcan reticle red dot could tighten things up a little bit. Regardless, really curious of side mounted setups.

 

[Zak Smith]

I use the Vortex side-mounted on several guns and it works great.

I'll elaborate a little bit. I ran these on a pair of SPR-style gas guns for a class (we did shoot to about 850 so we actually had to range, LOL). Two reasons-- first, I like to have a small red dot above the scope at the 12'o'clock position, and two, with the Vortex on the left-hand side, I can keep a shooting position and just read the display with my left eye. With the Vortex on top of the scope, I have to raise my head off the gun to read it.

 

[DogDown338]

I'll elaborate a little bit. I ran these on a pair of SPR-style gas guns for a class (we did shoot to about 850 so we actually had to range, LOL). Two reasons-- first, I like to have a small red dot above the scope at the 12'o'clock position, and two, with the Vortex on the left-hand side, I can keep a shooting position and just read the display with my left eye. With the Vortex on top of the scope, I have to raise my head off the gun to read it.

That’s exactly what I’m looking to do. Mount it left side as close to receiver as possible. And have a 12 oclock dot. Do you remember the handguards used or how you mounted it?

 

[Zak Smith]

I think one gun had a Spuhr mount and the other had an M-BRACE (American Rifle Co), both with the correct adapters to put things in the correct positions. Everything was mounted to the unified scope mounts.

 

[dgheriani]

Hello everyone. Brand new to WMLRF,
I’m looking at the vortex and new tango wmlrf’s and am just curious why I don’t see them side mounted anywhere. I run a Seeking SP10M in 6.5 and Seekins told me the rail is rigid enough for it, also contacted vortex about zeroing the system from a side mount. They said it was no problem as long as the rail was stiff enough.

I love running a 12 oclock red dot over my optic (March 4.5-28). So in theory, if I zeroed the red dot at 100 yards and the wmlrf, i would never have to dial back to zero between shots before ranging. Could simply put my red dot on target and tap my range button. Am I missing something. Please educate me.

I think the hardest part of what you want to do will be properly setting up the parallel zero with your Impact and red dot. Vortex include a target for zeroing the Impact but since you're using a non-magnified RDS you'll have to zero close enough that you can see the viz laser and the reticle of your red dot with the naked eye. Since it's a parallel zero you could do that super close but you'd want to verify at distance since any discrepancy in your side-to-side zero would make things funky at distance (ie you'd get the range of the things beside what you're aiming at).

 

[dgheriani]

I'll elaborate a little bit. I ran these on a pair of SPR-style gas guns for a class (we did shoot to about 850 so we actually had to range, LOL). Two reasons-- first, I like to have a small red dot above the scope at the 12'o'clock position, and two, with the Vortex on the left-hand side, I can keep a shooting position and just read the display with my left eye. With the Vortex on top of the scope, I have to raise my head off the gun to read it.

Hey Zak, what was it like to sling up for carrying with the WMLRF on the left hand side? That was always what I saw as the weak point in that setup, figured the rangefinder would catch on your gear.

 

[Zak Smith]

I think the hardest part of what you want to do will be properly setting up the parallel zero with your Impact and red dot. Vortex include a target for zeroing the Impact but since you're using a non-magnified RDS you'll have to zero close enough that you can see the viz laser and the reticle of your red dot with the naked eye. Since it's a parallel zero you could do that super close but you'd want to verify at distance since any discrepancy in your side-to-side zero would make things funky at distance (ie you'd get the range of the things beside what you're aiming at).

Ah, well, you get a parallel/offset zero on the LRF using your scope reticle dialed back to 0, and then as a second step, you can co-zero your red dot to the scope optically.

 

[Zak Smith]

Hey Zak, what was it like to sling up for carrying with the WMLRF on the left hand side? That was always what I saw as the weak point in that setup, figured the rangefinder would catch on your gear.

Eh, not really an issue

 

[SkyScrapin]

it’s very possible to get shift if you mount it towards the end of a rail on most weapon systems. The further you shoot, the more problematic it can be.

Keep it close to the action and you will be fine.

 

[JR1200W3]

If you make your LRF zero with the red dot at 100yds then whatever the offset is from the red dot will be doubled at 200 via divergence, and compounded at distance. Generally not a good way to co-witness WMLRFs. You really want the laser to be parallel to your reticle or aiming device all the way to infinity, which is generally impossible so zeroing it at something like 1000 ensures that, while it may not be completely parallel, will be as parallel as you can get it from 0 - 1000. Being parallel means that the laser will never be more than the distance of your HOB from your reticle(or aiming device). In a 12 o'clock situation that's about 3" directly above your reticle. So when you aim at a target and lase, your laser will only be 3" or less from the exact point on the target where you're aiming. If you zero the laser to the center of your reticle at 1000, then that offset starts at 3" and gradually lessens until it is POA/poi. And then commensuratly diverges past 1000 by the same rate until it's offset again by 3" at 2000. This is the easiest and generally most accurate way of zeroing a WMLRF. And it can be done using road signs or tail lights on vehicles.

So if you side mount it you have a 2 axis offset to deal with. Which isn't a show stopper but does provide more opportunities for error. As you can imagine, what I described above is a theoretical optimum but there can be errors and gremlins. So doubling your offset considerations with another axis isn't optimum.

And then losing the optimized aiming capabilities of a $4000 magnified optic in favor of a non magnified $500 red dot is probably not the best way to employ a device that is in reality still in it's nascent stages of development and is prone to it's own issues with zero retention.

In my opinion, side mounting on a forearm, aiming with a red dot, and co-witnessing at 100 would be The worst way to employ a WMLRF.

 

[Zak Smith]

I just measured the actual offset in inches vert. and horiz. and then did a true parallel zero, and then verified at distance. The primary was done around 40 yards and when I verified at distance it was dead on. Even if you get a co-witnessed (ie not parallel) zero at 1000, you won't have more than the absolute distance between the laser/sensor and scope center at the gun, at 2000 yards. The problem I had with using a far object to co-zero the LRF was that the visible laser on the Impact is pretty weak and seeing it at a distance was hard. You almost need a semi-reflective sheet to know when you're close, and then a very reflective small (e.g. 1") dot on that, at the exact linear up/down/left/right offset vs. the scope aiming point.

Using a red dot for aiming is a red herring and not really relevant to if the LRF is side or top mounted. For example, you can run a top-mounted LRF with a red dot at 9, 3, or 1:30 o'clock and the considerations for how you actually aim the LRF are the same. Or you can have a side-mounted LRF and not even have a red dot. They are separate topics. The biggest advantage of a side mouned LRF is the ability to read the screen without majorly disturbing the shooting positition.

Having a red dot on a gun set up with a "long range scope" is pretty useful, especially for gas guns (e.g. SPR/DMR) that might be employed faster or at a much shorter distance. Just from my experience with the setup, there are times when it was much easier to range using the red dot, and there were times when we had to aim with the scope.