Sacrificial window for scope's objective lens.

[Vorpalis]

Does anyone know if a sacrificial window, or something like a UV filter for camera lenses, is available for rifle scopes? I'm mounting a Sig Tango 6 3-18x44 on a bullpup, and with proper eye relief the objective lens is just behind the muzzle brake, so I'd like to protect the lens. I've done some digging on Euro Optic, and the closest they have is a see-through lens cap from Tenebraex, which, obviously, is not a great solution. I've also talked to someone at B&H Photo, and the least-terrible solution would be a step-up ring to a larger-diameter UV filter (my 44mm objective lens is just a weird size in the camera world). Given how much scopes cost, and that they're constantly around burnt powder (not to mention dusty environments), it just seems strange that this isn't a common thing. So, does anyone have any ideas?

Thanks!

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[The Heretic]

You should be able to find a 44mm UV filter - I googled it and saw a lot of results.

 

[Vorpalis]

Thanks, Heretic! I definitely Googled it before posting. Clicking-through those results, most aren't actually 44mm (Google's doing its closest match thing), and the few that are either have a tint that I don't want or don't give the thread pitch. I have found one that might work, but I'm waiting to hear back from Sig about what thread pitch the scope has.
I appreciate the help!

 

[The Heretic]

There is this too:

LUCID OPTICS Flash Filter for 44mm Optics | Lucid Optics

www.lucidoptics.com

Won't completely protect the objective lens but is better than nothing.

You might also get some mitigation with a longer flash hider, especially one that has the top "vents" blocked/missing. And there are the devices that go around flash hiders and other muzzle devices to direct the muzzle flash/etc. forward. Saw a vid on one just the other day - meant to reduce concussion when shooting on a range.

 

[Vorpalis]

These are good ideas—thank you!

 

[Stomper]

The obvious solution is to put a suppressor on the end of that bad-boy!

 

[Retired Guy]

I think the Tango 6 comes with a sunshade, You could use that to deflect the muzzle blast. It will likely get discolored from use but better the sunshade than your objective lense.

 

[Member 53328]

I second @Stomper. Get a can for it.

 

[Camelfilter]

Likely easiest, least expensive solution would be a butler creek Blizzard flip cap.

You may have to get creative with sizing, ie get a larger one & wrap some electrical tape for snug fitment.

Also, dependant upon blast, may have to further modify it to prevent inadvertent opening due to blast. Simple enough to do, I'd wager. Glue it shut.

Linky no worky...so Google :

Butler Creek Blizzard Caps

 

[Mark W.]

All old school camera lens filters have the same thread pitch .75mm. if your scope uses the same pitch then a simple 44mm to 49mm step up ring would allow you to put any 49mm camera filter on the scope. A 1A Sky filter will be the clearest with a UV Haze filter next inline. eBay is a great place to find odd step up rings.

RISE(UK) 44mm-49mm 44-49 mm 44 to 49 Step Up Ring Filter Adapter black | eBay

The 44-49mm ring adapter easily screws onto the front ofany 4 4 mm lens, and converts the thread size of your lens to the thread size of anyother 49mm accessory (such as filters, hoods, flashes and lens converters).

www.ebay.com

 

[P7M13]

The obvious solution is to put a suppressor on the end of that bad-boy!

but then it will get blow-back gunk on it.

 

[Vorpalis]

Thank you to everyone for all the ideas and leads!
I found B&H Photo has the right-sized step-up ring with the correct 0.75mm thread pitch, as well as clear, optical glass UV filters meant for cameras, so I ordered those to try. I may add or swap these for a killflash, since Tenebraex makes one that fits inside a Butler Creek lens cap. I'll report back once I've had a chance to shoot it.

 

[Ginocide]

I've seen people in the airsoft world use these (or things like them) to protect their optics from incoming BBs. You might not think it at first glance but those BBs can break beer bottles so people do worry about their sights with good reason. Pretty basic but they seem to do the trick. Replacement lenses are cheap as well.

 

[Hueco]

Does anyone know if a sacrificial window, or something like a UV filter for camera lenses, is available for rifle scopes? I'm mounting a Sig Tango 6 3-18x44 on a bullpup, and with proper eye relief the objective lens is just behind the muzzle brake, so I'd like to protect the lens. I've done some digging on Euro Optic, and the closest they have is a see-through lens cap from Tenebraex, which, obviously, is not a great solution. I've also talked to someone at B&H Photo, and the least-terrible solution would be a step-up ring to a larger-diameter UV filter (my 44mm objective lens is just a weird size in the camera world). Given how much scopes cost, and that they're constantly around burnt powder (not to mention dusty environments), it just seems strange that this isn't a common thing. So, does anyone have any ideas?

Thanks!

If the objective is just behind the break, then attach the lens hood and that should extend cover to past the break, no?

In this case, a filter may be worthwhile...that being said, as a photographer of over 12 years...I hate the things. Scopes don't have photo quality glass to begin with and adding junk glass on top will lead to image degradation, worse glare and ghosting in tough lighting situations...

And filters are not anywhere near as tough as that front lens...if they shatter, those shards can scratch your front lens up. The type of impact that your scope would laugh off can kill the filter and cause the filter to damage the lens.

So...if it were me, I'd just use a lens hood and call it a day.

 

[Vorpalis]

@Hueco
Those are all good points about the filter. And yes, the top port on the brake is right under the sunshade. So you think the sunshade can withstand the jet of hot gasses from that port?

 

[Hueco]

@Hueco
Those are all good points about the filter. And yes, the top port on the brake is right under the sunshade. So you think the sunshade can withstand the jet of hot gasses from that port?

Possibly. Take a few test shots and see if it's absorbing some heat. Could be that it will be okay...could be that it'll take a beating under long and continuous fire. If it's going to take a beating, a suppressor cover may work to shield it.

Keep in mind that, even if you go the lens route, you may have to solve for this beating (keeping the filter from frying up in the heat/staying clean).

Another option may be to just change the break. I run a Gen3 Little Bastard from American Precision Arms and quite like it. The ability to port gases up is controlled by user-defined screw holes.

 

[Jonnyuma]

Another option may be to just change the break. I run a Gen3 Little Bastard from American Precision Arms and quite like it. The ability to port gases up is controlled by user-defined screw holes

An even cheaper option might be an extended A2 birdcage flash hider with no bottom holes... just mount it 180° opposite it's intended orientation. Maybe use a thicker crush washer to get it there.