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Atarget
May 01, 2014, 18:59
I am thinking of getting a Gemtec Halo suppressor and QD mount for my HK 91,
Any opinions or other options?
Thanks for any input.

ALL FAL
May 01, 2014, 20:25
Good unit, but wait a while and the Civil WarII will start and then put any can ya want on it, SCREW the BATFE, why send those scumbags $$$$$ to have what You want?

W.E.G.
May 01, 2014, 20:33
I had one.

Repair of baffle-strike damage was expensive.

http://i227.photobucket.com/albums/dd7/rkba2da/rifle%20pics/AR-15/HALOcrack2-1.jpg



http://i227.photobucket.com/albums/dd7/rkba2da/rifle%20pics/AR-15/Gemtech/Gemtechrepairinvoice.jpg

Stranger
May 01, 2014, 21:47
I am thinking of getting a Gemtec Halo suppressor and QD mount for my HK 91,
Any opinions or other options?
Thanks for any input.

Your HK91 is 7.62, correct? The Halo is a 5.56 can. Not the best choice, unless you like grenading expensive parts on the end of your barrel.

Regardless, I would stay away from Dater and Gemtech. They are assholes and rip-off artists, IMHO.

A better choice would be a Silencerco Specwar 762 or Saker 762.

Tyris
May 02, 2014, 12:11
That flash-hider mount is crappy and wobble prone. The baffle strike does not surprise me.

Gemtech's "bi-lock" is another poorly designed mount. I've seen them get carboned up and refuse to come off. Gemtech's suggested fix? unlock it and launch it off into the dirt 50 feet down range.

If you must have a fast-attach can, get one purpose built for it. YHM makes a very solid mount, surefire does too. I have not played with the latest from SWR, but have heard good things. Of the 3 AAC mounts I have ( I am a slow learner apparently ), two needed to be machined to fix the lockup happening on a hill instead of a valley resulting in a ton of wobble and poor lockup. Those that have them know what Im referring to. AAC's never acknowledged the problem, and just kept increasing the number of teeth for the ratchet mount every generation without addressing the root cause of the issue. Will never buy one of their cans again.


One more thing to consider: the HK91 is not terribly happy running with a can. The additional back pressure will mess with the timing of the delayed blowback system. To fix this you MUST start using alternate locking shoulders and maybe different size rollers to fine tune it or you will eventually batter that gun to death. I went through the same process on an sbr/mp5k, I shudder to think what a mess it would be to repeat on a 308.

I'd move to a nice bolt gun + can and spare the headache of the hk91 + can. FAL + can is another interesting adventure.

-T

Atarget
May 02, 2014, 15:02
Thanks for the replies, gives me more to think about. First venture into the world of cans ans just starting the learing curve. Thought it better to learn from those that have already.
All fal, because for now its the leagal way to go!

Tyris
May 02, 2014, 17:19
Thanks for the replies, gives me more to think about. First venture into the world of cans ans just starting the learing curve. Thought it better to learn from those that have already.
All fal, because for now its the leagal way to go!


If this is your first silencer, I'd start with something that is actually quiet.

Rifles cans in general are not what I'd consider quiet, not meaning that they don't significantly reduce the report of the shot, they certainly do, but compared to a pistol can in 9mm or especially 22LR, they're obnoxious (particularly on semi autos) and I would not use one without hearing protection. Others do, but I intend to keep my ears intact :D

Rifle cans are more about being civilized and not pissing off your neighbors than actually being hearing safe for the shooter. Just my opinion.

And, no I've never heard a 45acp can that I considered quiet either except when run "wet", which is in my opinion is retarded, the only exception being the integral 45acp rifles which were sufficiently large.

I'd start with a nice stainless / take-apart 22 can or a good 9mm can, preferably 1.38" diameter, not that 1.25" shit. (dont ask how I know about avoiding that mistake). Once done and satisfied, get a good rifle can.

-T

lightguy
May 02, 2014, 18:05
I dont have a can for my 91 but I have been told by the "Experts" that putting one on will screw up the receiver because of the added back pressure vs the lock rollers.
If I get off my ass I'll be getting a SpecWar7.62

Tyris
May 02, 2014, 18:18
I dont have a can for my 91 but I have been told by the "Experts" that putting one on will screw up the receiver because of the added back pressure vs the lock rollers.
If I get off my ass I'll be getting a SpecWar7.62

You can mitigate this by moving to a more aggressive locking shoulder to delay the unlocking.

The shitty part about the whole HK roller lock is that it makes the 91 sensitive to running silenced/not silenced. You'd ideally want to change out the locking shoulder based on can/no-can, which is a pain in the ass given how dirty the 91 runs.

On my mp5k, I can run with or without a can when using the can-specific locking piece. It just gives it a more gentle recoil. In the 308 I suspect it would be a bit more dramatic and render the gun less reliable.

-T

doneill
May 04, 2014, 09:02
Thanks for your posts. It is clear that you know of what you speak and share helpful information. This is not unique, but it is appreciated. I'm on a suppressor learning curve and like to find out about issues like those you describe with the locking shoulders. Eventually I may try to suppress my FAL

To add my 2c's. Second that a good 9mm can is versatile. I use mine on several .22 (rifle, smg's and belt fed .22 mg.), 9mm. and 38 spl/.357 carbine. I use a Bowers CAC 9 that has interchangeable mounts on all of these. Bowers cleans the can for $20 with lightning fast turn around so I can run a thousand or so .22 through it and once it bunks up (Highly technical term I know) avoid the lead exposure and hassle of cleaning it. I like Bower's customer service, but this is not a dig against other can makers. I know that Coastal also makes interchangeable mounts and has a good baffle stack, but I don't know about cleaning services. I'm sure that other manufacturers can provide different mounts, but the mount must always be an accessory for the gun and not a suppressor part, otherwise each mount is legally a separate suppressor.

I'm waiting (3 months) for the form 4 for a titanium .223 can that I will also use on .22 rifles and pistols. It will be significantly smaller and lighter than the CAC9, but the downside will be that I will need to clean it myself.



Dave O'Neill

Tyris
May 05, 2014, 01:45
HK locking pieces all have different angles for different purposes. The locking piece in combination with the roller sizes dictate the speed at which the action unlocks. I am most familiar with the mp5 series as that is the only roller-lock gun I have (unless we start stretching and looking at the venerable CZ52 :love: ). They have 3 commonly available angles: 110-degree, 100-degree, and 80-degree. The 80 is intended for use with a silencer as it slows the unlocking of the action. I tried all three and eventually settled on the 80 for general use, it does slow things down if run without a silencer and makes the recoil next to nothing when run with a sufficiently small bolt-gap, enough that my wife will occasionally join me at the range :D. You'll need to find the equivalent correct locking pieces for the HK91, wrong angle in one direction and you'll unlock too soon, wrong angle in the other direction and you'll delay the unlocking too much impeding reliability. The inconvenience of probably needing two locking pieces is a bit of a deterrent from running an HK91 with a silencer. There are simply better platforms that work with less headache. Again, all just my opinion.

Read more here:
http://www.hkpro.com/index.php?option=com_content&view=article&id=135:guide-to-hk-locking-pieces&catid=4:special-topics&Itemid=5

I met Tom Bowers several years ago when I bought a 40 cal pistol can from him. He is a nice guy, and I'm fortunate to have a bunch of class3 manufacturers around my area. I actually bought my first silencer from an apprentice of his around a decade ago, the can was based on an early bowers' design, but used m-baffles instead of K's. It is not particularly quiet, but does well enough on a mac11. Mine comes apart for cleaning.

One word of caution about 22 and sealed cans (presuming that your titanium can is sealed): there exists no sane method to dissolve out vaporized lead splatter (no, I dont consider production of lead acetate via "the dip" (h2o2 + acetic acid) to be sane). That shit is highly toxic and will result in some serious retardation as well as literal poisoning of the water supply should you chose to pour it down the drain. It will soak through your skin should you get it on you. My humble advice: dont go there, not even obama care will cover the ill effects :D

To clean 22LR effectively the silencer must be user openable, if it is not it will gradually but eventually fill and become loud. Continue using it after that you'll fill it to the point where the vaporized deposition will close the aperture resulting (eventually) in a baffle strike.
Gemtech used to run a line comparing cleaning car mufflers and cleaning silencers. Horse shit. Vaporized lead mixed with caked on carbon is not to be underestimated in its stubbornness. I've found its removal requires ultrasonic cleaning mixed with physical agitation (read: elbow grease and a good steel brush). Gemtech no longer uses that line and have bowed to market pressure and released some user serviceable silencers (I have one of their Alpine 22LR cans in stainless) which are quite quiet and a very well thought out design. Several other manufacturers make nice stainless 22 cans too.

In summary: I would not personally run 22LR through a sealed rifle can as there is no effective way to clean it.

-T

doneill
May 05, 2014, 22:14
and agreed it is a tough cleaning job.

I wonder if you have experience using a .223 suppressor on a .22 lr then running a few mags of .223 through it? I would suppose that the gasses would tend to scour, evaporate and blow the lead out, but I wonder how much crud would be left behind. I worried about the ethics of releasing the lead from the suppressor into the atmosphere, but I guess is is not worse than firing a .22 lr without a suppressor. The lead goes into the atmosphere, we just don't see it. I've decided that shooting .22 lr with a suppressor that condenses some of the lead and collecting and properly disposing of the lead in the can is the most environmentally friendly way to shoot .22 lr.

Dave O'Neill

gunplumber
May 06, 2014, 09:00
That flash-hider mount is crappy and wobble prone. The baffle strike does not surprise me.

Gemtech's "bi-lock" is another poorly designed mount. I've seen them get carboned up and refuse to come off. Gemtech's suggested fix? unlock it and launch it off into the dirt 50 feet down range.

If you must have a fast-attach can, get one purpose built for it. YHM makes a very solid mount, surefire does too. I have not played with the latest from SWR, but have heard good things. Of the 3 AAC mounts I have ( I am a slow learner apparently ), two needed to be machined to fix the lockup happening on a hill instead of a valley resulting in a ton of wobble and poor lockup. Those that have them know what Im referring to. AAC's never acknowledged the problem, and just kept increasing the number of teeth for the ratchet mount every generation without addressing the root cause of the issue. Will never buy one of their cans again.


One more thing to consider: the HK91 is not terribly happy running with a can. The additional back pressure will mess with the timing of the delayed blowback system. To fix this you MUST start using alternate locking shoulders and maybe different size rollers to fine tune it or you will eventually batter that gun to death. I went through the same process on an sbr/mp5k, I shudder to think what a mess it would be to repeat on a 308.

I'd move to a nice bolt gun + can and spare the headache of the hk91 + can. FAL + can is another interesting adventure.

-T

All good point, although I've not had issues with my AAC 51T, the HK 91 sucks as a suppressor platform.

Atarget
May 06, 2014, 14:34
Thank you one and all!
Great information for me. I was thinking of the HK91 because it is .308 and the largest caliber i would want to suppress and the gemtec for the ease of mounting.
I understand the roller locking issues now and how the suppressor would effect timing. What about a rotating bolt like an AK or Galil?
I would like try to use something i already have and not purchase another rifle right now.
Again, thank you all for the feedback.

gunplumber
May 06, 2014, 15:02
semiautos blow a lot of gas out the e-port. They don't suppress as well as bolt actions. If you are looking for a gun for a .308 suppressor, I'd look at a piston AR with a suppressor setting - LMT, LWRC, etc. - the Sig seems like the best value, although I went with the SCAR. It's hearing safe, but it ain't like the movies.

Tyris
May 06, 2014, 16:01
You could silence an AK. Make sure the threads on the muzzle are CONCENTRIC to the bore. I had my 5.45 SAR2 threaded 1/2x28 so it could take standard 5.56 silencers. Worked well but was loud because of the holes on the gas block bleeding off so much high pressure. Made my ears ring.

My dealer and I ended up welding up the gas block holes and moving to a beefier recoil spring. This trapped all the gas in the gas tube and quieted it down to the point where it would not ring my ears. By no means was it bolt gun quiet, but far better than no can, and better than a standard AK + can.

As GP stated, semi's are going to be louder than bolt guns. I've never had good luck with the AR platform, I seem to have some jinx where the AR's owner swears up and down "oh yeah, this thing has never jammed!!", I go to fire it and poof! double feed! or failed extraction, or who knows what. I have not tried a SCAR, but if I was getting a 308 semi, that is what I'd buy. Otherwise, get a nice 308 bolt gun, I've been eyeing the DTA SRS, because it is so short :D

What I've personally found is, I can shoot 223 or 308 bolt guns without ears, I can not shoot semi-autos without ears comfortably.

Let me re-iterate my initial advice: get a $100 threaded barrel for your favorite 9mm, a case of jacketed 147gr ammo and a nice 9mm can like the Octane9, and be happy. Or thread the barrel on your ruger mk3 or cz452 and get a steel 22 can, super quiet with ammo that stays subsonic out of 4" or 16" barrels respectively. Any of the above will be substantially more quiet than a 308 semi.

-T

hairygreek
May 12, 2014, 00:34
Would a FAL on grenade setting be equivalent to a bolt action for suppression? All the gas should go out the barrel right?