I am wondering if anyone has an idea of where I might find a PVS 27 Muns operator's manual. I bought the sight second hand and it came without the manual. I called FLIR but they told me they were unable to supply the manual because of classification. Since I don't have past experience with clip ons I'd like a manual to make sure I'm using and maintaining it properly, ect. Appreciate any leads you guys might have!
-
Having trouble using the site?
Contact support
Night Vision Looking for An/PVS 27 Operator's Manual
- Thread starter fujam
- Start date
If no one comes up with a copy, I can scan the relevant pages and quick reference card from mine.
i have quick card that come with mine i can scan for you. there's really nothing for maintenance at the user or even unit level. keep it clean, dont wipe the lenses with sand paper, use lithium batteries in them if your smart. take the batts out if you leave the unit sit or store the unit for more than a couple weeks. treat it like its a precision optical instrument and not a fucking rock and you'll be fine...
Thank you for the replies. Good to know that there is not too much to know. My concern is muzzle blast. I have desert tech srs a1 and the muzzle on one of my barrels is basically right below the objective. I was concerned that the blast or carbon could damage the lens. Clearly a suppressor is the way to go, but unfortunately I'm governed by CA legislators and their dismal work. What would you consider best practice in this case to avoid damaging the unit or need I even be concerned?
well To be honest the manual doesn’t say anything in regards to running this clip on with a retarded bullpup design rifle that would be violently gassing the lens of the unit with carbon and debris. I would apply judicious common sense to this situation and avoid that level of fucking stupidity while posting said dumb ass bullpup for sale and buying a normal rifle where your face doesn’t sit directly above a fucking 60k PSI controlled explosion.
What do you think would be the minimum safe distances from muzzle to objective say for a 300 WM? I'm thinking a blast diffuser like the Sure Fire Warden might be a good solution, but not sure the system can be adapted to a 3/4" muzzle thread or can handle the blast of a magnum cartridge. I can fabricate something similar but am wary of manufacturing something which could be construed as a suppressor. Solutions which do not resort to replacing the rifle are appreciated.
At one time at least they sold 3/4" threaded socom adapters because that was the kac standard thread. You may be able to find one. Why not grab a longer barrel?
I'd like to find a solution be able to run both my short and longer barrels and stick with the DT platform, for the moment, although the AX looks like the apex preditor of factory rigs and I wouldn't mind having one. I'm suprised no one has told me to move out of cali and get a supressor
Thanks on the heads up for the socom adaptor, I'll look for one.
Thanks on the heads up for the socom adaptor, I'll look for one.
I'd like to find a solution be able to run both my short and longer barrels and stick with the DT platform, for the moment, although the AX looks like the apex preditor of factory rigs and I wouldn't mind having one. I'm suprised no one has told me to move out of cali and get a supressor
move out of Cali and get a suppressor
@fujam
Test. Cut two thicknesses of heavy cardboard that approximate the shape of the 27, but larger to cover the lense.... then add a white sheet of paper on front. Masking tape it on.... covering the lense.
Fire round. See if it damages or stains the white paper.... that will tell you what it will do to the unit.
Best to you.
Test. Cut two thicknesses of heavy cardboard that approximate the shape of the 27, but larger to cover the lense.... then add a white sheet of paper on front. Masking tape it on.... covering the lense.
Fire round. See if it damages or stains the white paper.... that will tell you what it will do to the unit.
Best to you.
Good idea, thank you for the suggestion! I'll run this test next time I get out shooting. I'll try to post the result.
Just my 2 cents but I would not put that unit anywhere near your muzzle brake regardless of what the paper and cardboard reveals.
The shock wave/overpressure is going to ass rape the 27. The large surface area facing forward is simply going to exaggerate the abuse it absorbs. Like a Sat dish, the face of your 27 is going to catch and transfer the shock wave.
It's rated up to 50BMG recoil. Muzzle blast is totally different abuse.
If you insist on rocking on, be prepared for sending back to FLIR for repairs not warranted.
Get the Warden or put an ASR brake with blast shield.
./
The shock wave/overpressure is going to ass rape the 27. The large surface area facing forward is simply going to exaggerate the abuse it absorbs. Like a Sat dish, the face of your 27 is going to catch and transfer the shock wave.
It's rated up to 50BMG recoil. Muzzle blast is totally different abuse.
If you insist on rocking on, be prepared for sending back to FLIR for repairs not warranted.
Get the Warden or put an ASR brake with blast shield.
./
@sinister
Mil experience thoughts on this ?
And just FWIW to the rest of you, same message was sent to long term Flir mil rep and to the project manager that relegates used mil night vision into the 10-33 program or the scrap pile.
Will report their answers when they respond.
Maybe Chip at TNVC will respond as well. @clasky
Mil experience thoughts on this ?
And just FWIW to the rest of you, same message was sent to long term Flir mil rep and to the project manager that relegates used mil night vision into the 10-33 program or the scrap pile.
Will report their answers when they respond.
Maybe Chip at TNVC will respond as well. @clasky
Last edited:
Jfwiw, I do know from very recent personal experience on two 11.5" sbr's, one with a flash hider, one with a muzzle brake, and a warden,
the surefire flash suppressor actually works to suppress the flash.
The warden on the braked unit creates a 24-28" fireball that the flash suppressor doesnt.
Have same recent experience with the Noveske flame pigs on SBR's and they move the blast ball forward.
And they both (pig and warden) trip the autogate on head mounted pvs14's.
The pvs14 mounted on the receiver behind an aim point really didnt like the pig or warden.
Have a few pics to post later in the morning.
That's all 556.
I would hate to see the blast ball out of a warden on a 300wm short barrel.
The 300wm fireball through a warden would definitely cause an autogate shutdown on the 27, and enough of those arent the best friend of the tube.
At this point, I have to agree with Terry Cross, post 16, about the satellite dish affect. I would not mount the 27 right over the flash suppressor or brake.
However, the cardboard and white paper test has been used b4 to see how much blowback came from a un-named suppressor mount that was in use at one time on a sbr. It would definitely tell you what was going to stain the lense of the unit.
Surefire flashlights mounted even with or just behind the brakes/flash hiders have survived up to 3000 rounds b4 being returned for repair. Other lights failed on the first shot. And this was 556, not 300wm. And all were stained to a light loss in a short period.
After Brother Cross so pointedly stated, the satellite dish effect, I would not mount the 27 over the brake.
That leaves the ASR brake with a blast shield as a possible...
Waiting on the replies to the queries otherwise.
Best to you.
vr
Last edited:
22 and 27 were designed for the rigors of combat where inadvertent blasts and pressure waves can beat the hell out of them. And they have been tested to a degree for that.
But, uncle had a bigger budget than the rest of us. And uncle had a company called Camber testing things out to include "test to destruction" , and some neat things were learned in those tests.
The following pic indicates what a 22 endured last night, just to see, based on some of the comments in this topic.
Some of us still participate in "test to destruction" on uncles dime.
The project manager responded this a.m...
1. No, I wouldn't put a 27 directly over a top blasting flash hider or brake.
2. Put a shorter optic on (the pic I sent to them)
2a. Turn a bird cage flash hider upside down to direct the blast away, or
2b. Put a 4" ish blast tube on it like put on xm177 clone ars.
Ymmv, and for educational purposes only to those who want to know little bits of information they might need in a bad place.
Could probably get by with mounting a 27 above the muzzle a couple of times, to save your life in a bad situation, but not recommended by most who understand what KSW said above.
Last edited:
I can't tell you what an SRS will do to a PVS-27 that close to a bare muzzle or side-blasting brake, but I can tell you a 7.62 AR-10 with similar will destroy very expensive spotting scopes placed next to the shooter off the left shoulder in prone and sitting firing positions. 
Your call.
Your call.
Flir mil rep responded.
No no no no no no no no no.......
One shot, one kill, kill the 27, directly above the muzzle, especially a muzzle venting up.
Minimum 4" behind a shielded brake, and then there will probably be some damage.
Repeated, no no no no no no no no no.... do not put the 27 directly above the muzzle.
What else can be said...
Best to you,
VR
jw
No no no no no no no no no.......
One shot, one kill, kill the 27, directly above the muzzle, especially a muzzle venting up.
Minimum 4" behind a shielded brake, and then there will probably be some damage.
Repeated, no no no no no no no no no.... do not put the 27 directly above the muzzle.
What else can be said...
Best to you,
VR
jw
Thanks for getting this info from the horse's mouth! It makes sense and is why I asked the question before trashing the unit. I dont know the physics but I imagine blast energy is calculated by something like the square or cube of the inverse distance, so right over the break is likely 1000s of times more voilent than a foot back. For reference my 300 WM barrel is 28" but that still only puts the objective 6" behind the muzzle due to the bullpup's design and a longish scope. In this case taking the break off may be better than having it on, or better to avoid mounting it on this rifle altogether as @Killswitch Engage has been recommending. Thanks for all the info and everyones' time. Good to have all this knowledge as a resource. If I do go the route of a blast tube and figure out a way to mitigate the fire ball without running afoul of the ATF by making something that could be construed as a suppressor, I wonder what it does to a rifle's accuracy other than obviously changing barrel harmonics. Seems to me like it might create turbulence which throws off the projectile, but maybe it's not a big enough factor to be noticed. Anyways that's another topic. In the mean time I'll check out the asr brake with blast shield.
Last edited:
The ASR with shield kinda looks the same as the Warden but with a open end rather than a bore hole and slotted vents . My guess is the fire ball will be just as bad as the Warden's. Man, suppressors should be legal in all states, I hate California's gun laws
Actual flash signature varies wildly with your ammo/propellent. Lot of the new production Mil stuff and a good bit of the commercial stuff has low flash propellant's.
So..... don't base your flash observations off of one ammo type or somebody blowing some old 855 ball through their gun.
Regardless of flash, I can attest to the Warden and SiCo blast shield putting almost all of the blast forward. In fact, using SBR 5.56s with ass loads of headache, sinus bleed, retina detaching port pressure, both of these muzzle devices are WAY, WAY more pleasant to a team mate on the same line than even a bare muzzle or A2 Birdcage.
An economy approach that has similar properties for patrol rifles and duty carbines is the Troy Claymore. That gives somewhat of a "brake" muzzle control but puts 100% of the captured muzzle blast forward. Noticeably quieter to the shooter compared to A2 birdcage and similar.
This shows a little of where the gases are going when using different brakes. As already determined none look too promising for the health of 27 or its objective lens.
precisionrifleblog.com
Muzzle Brakes: Muzzle Blast & Ground Signature
Muzzle brake designs vary widely, and their blast pattern varies significantly as well. I wanted to ...
precisionrifleblog.com
That's interesting to know about flash signatures! I also forget, short barrels shooting factory loads are going to be fire ball makers as a good bit of powder is burning outside the barrel.
I've been using Ramshot Magnum as a replacement for H1000, and 220 SMKs so the powder might be mostly burned up by the time it gets to the end of the 28" of barrel. Its not a super hot load either, doping out to right around 2750 fps. I could also slow it down for night shooting as I've got another good node right around 2600. Less powder should = less flash?
Perhaps the ASR or Warden could provide a solution. My other challenge is a 3/4 x 24 thread and a lot of these attachments suggested seem to go from 5/8 to the M18 of Sakos and AIs skipping the rarer 3/4" threads. I looked at the Troy Claymore and it looks like a good piece of gear but alas I only see the 7.62 in 5/8 x 24.
I see that now, somehow missed it when I first scanned their website. Thanks for the tip!
An update...
I made it out to the range, finally, to do a little testing. I got a 4" sewing hoop and put a paper towel in it as an indicator for blast pressure. I figured if a paper towel can survive the blast and stay clean the 27 shouldn't be damaged. I also figured the white fiber would distinctly show any carbon or fouling. With my 300WM barrel the muzzle is about 6" in front of where the lens of the 27 would be if it were mounted to the rail, which is where I placed the sewing hoop + paper towel. Using a brake the paper towel was ruptured and torn on the bottom indicating a good bit of blast pressure parellel to the rail. It's not something I'm willing to risk subjecting the clip on to. However if I removed the brake the paper towel was intact and perfectly clean after 10 shots. So I'm thinking a solution may be a quality flash suppressor like a Smith Enterprise Vortex to reduce muzzle flash and then repeat the test to check that the blast's vectors are not changed. If the paper towel is still showing no issues I'm thinking I'll be GTG to mount the 27. Does this seem logical to the guys with more experience? Thanks again for your help and feedback on this subject!
I made it out to the range, finally, to do a little testing. I got a 4" sewing hoop and put a paper towel in it as an indicator for blast pressure. I figured if a paper towel can survive the blast and stay clean the 27 shouldn't be damaged. I also figured the white fiber would distinctly show any carbon or fouling. With my 300WM barrel the muzzle is about 6" in front of where the lens of the 27 would be if it were mounted to the rail, which is where I placed the sewing hoop + paper towel. Using a brake the paper towel was ruptured and torn on the bottom indicating a good bit of blast pressure parellel to the rail. It's not something I'm willing to risk subjecting the clip on to. However if I removed the brake the paper towel was intact and perfectly clean after 10 shots. So I'm thinking a solution may be a quality flash suppressor like a Smith Enterprise Vortex to reduce muzzle flash and then repeat the test to check that the blast's vectors are not changed. If the paper towel is still showing no issues I'm thinking I'll be GTG to mount the 27. Does this seem logical to the guys with more experience? Thanks again for your help and feedback on this subject!
Similar threads
