Ok so let me start by saying this is my first complete AR build from scratch and 3rd AR owned. My caliber of choice is 5.56 since this is a do-it-all survival build.. I want this rifle to be shor enough for cqb but also be able to reach out at a couple hundred yds if need be. Has to run reliably suppressed and unsupressed. I am hoping to add as minimal barrel length as possible with a suppressor so have been wondering about the reflex type suppressors. Can these still be purchased and had in the u.s.? If so where? Where I cant seem to get a straight answer is what gas block and handguard can I use? I prefer a non adjustable gas block and before people start praising the w.a.r. upper, ive decided against it. I prefer for my handguard to come right to the start of my reflex suppressor if possible. Do not need a long handguard as I will only be adding irons, optic, and sling.

So heres what I have...

Spikes lower
cmmg lower parts kit
ati scorpion grip
geissele ssa trigger group
milspec buffer tube
damage industries chrome silicon spring
cmmg carbine buffer
b5 sopmod enhanced stock

Heres what I plan to get so far....


Seekins upper
BCM 12.5" carbine barrel 1/7 twist chrome lined
BCM bolt carrier group and bolt
BCM gunfighter medium charging handle

Accessories and optics I plan on getting....

Two point sling
troy iron sights
trijicon vcog optic(open to suggestions)

What im not sure about.....

Is it possible to get a reflex suppressor? If so how

What handguard can I use that will work with low pro gas block?

Can I use non adjustable gas block and be ok both unsupressed and suppressed?

What buffer will best serve my needs and keep my rifle cycling reliably suppressed and unsupressed?

You may want to look at the Griffin reflex suppressors, OPS are the more popular traditional models.  This should work great for you with a 11.5 or 12.5" barrel.

Are these available for purchase in the u.s.? Everything I search on reflex suppressors brings me to canadaian websites

Well! Hello me a few years ago! I have been through exactly what you are thinking of building, and I'd like to share my observations:

Rifle in question: 12.5" DD barrel, Mk18 rail (~9.5"), AAC SPR/M4 suppressor (Reflex mount, NLA but similar to Griffin SPR)


Now, that's a 12.5" barrel with a reflex suppressor. So, it still adds about 6" of barrel length. Let's put that into perspective:


Yup, that's your 12.5" rifle with suppressor being as long as an 18" Mk12 with the same stocks in the same position. The Griffin SPR should mount about the same in terms of length added.

NOW, with that being laid out, here's another option:
Allen Engineering AEM2

That's also a reflex suppressor that adds far less to your overall length. A 6" suppressor reflexed on a 12.5" will be very short, possibly the same or less as a 10.3" CQBR with NT4 or Surefire SOCOM. The AEM2 is also nice because you can use any barrel with a proper M4 shoulder on it. AE or ADCO can help make sure your barrel will work.

In my experience, the 12.5" barrel is nice, but in the end the whole package doesn't feel at all like the lightweight SBR I'd envisioned. If I were you, I'd either use the AEM2 as above and a ~9" rail like the Centurion CMR or Geissele SMR, or get a muzzle-mount compact suppressor that's lightweight. A 12.5" with a compact suppressor will be more pleasant than an unsuppressed M4 without ear-pro, it'll have a bit more oomph than a 10.3" rifle, and it would be great as an all-arounder within the limits of the 5.56mm rounds available.

Also, try to stick to 1 can per rifle. The brake is good for the 12.5" as long as you leave the can on. Without the can it will be pretty damn blasty.

I actually couldnt find much on griffin but the ops look great and available to u.s.! So now im trying to decide between ops 12th, 16th, 15th, or 14th....
Anyone wanna chime in on gas block options as well as buffer and handguards?

Lancecriminal, thanks for the long response. That first sand colored rifle is really close to exactly what envisioning mine to become. I cant seem to find any aac or griffin reflex suppressors online but the ops look like a good option. Definately want to go reflex to save on length  and I like the idea of the suppressor really centering itself on the barrel. I really like that rail also. How does it run both suppressed and unsupressed? Also what gas block and buffer you run?

This is relevant to my interests. Anyone know if the ops inc m4-s is available? I've tried to contact them directly and checked all their venders in my state with no luck.

The OPS, Inc. suppressors were originally designed by Ron Allen.

Ron Allen is now building and selling almost perfect reproductions under his own brand name, Allen Engineering.  

Most of the folks getting suppressors for their MK 12 SPR projects are getting AEM5 suppressors now.  

Many of the companies who used to stock OPS, Inc. are now selling AE suppressors.  

I've also already asked him about building suppressors that are not "on the menu," including a replica of the old 3rd Model, which he affirmed that he could do, though it would not necessarily be what you're looking for for this project.

~Augee

Great info Augee, thanks!

Yea thanks augee! Good info.  This is off topic but just want to say this is my first post on a firearms forum. Been on alot of car forums. But man the support and ability to have a good discussion and help eachother and support one another in exercising our right to bear arms is incredible here. Im sure there are negative posts occasionally but I really appreciate you alls help!  Great first impression of this forum!

Does anyone want to comment on gas block and buffer options? Also how can I be sure my rifle will run unsupressed, suppressed, and with subsonic ammo?

You can go the adjustable gas block route, etc. - but for the most part, an H or H2 buffer and any conventional gas block made of the right materials/specifications will work just fine suppressed and unsuppressed, and despite the many "accelerated parts wear" objections - will probably functionally out live most ARFCOM members' uses - which is particularly true considering that by the time you could have worn it out, you may have added more ARs, and/or decided another one was your new favorite, and are now using it more often than this build.

As for subsonic 5.56MM - for all intents and purposes, you're simply not going to find a commercially available 5.56MM subsonic that will reliably cycle in your rifle.  Every now and again, some company will come up with some "new" thing that they claim will allow it, whether it be a new round or a new upper/suppressor combination, but they rarely seem to stick around too long, and are practically too limited in application to gain much traction.  

The few rounds that do exist are almost always prohibitively expensive, or not sold commercially, or both.  

If you want to run subsonics, your best bet is to look at other caliber options, e.g. 9MM or .300 BLK.

~Augee

I'll chip in too:

I saw you discounted the WAR off the bat, not sure why. The very rifle above has one of their earlier ones, and runs great. The switch plain works, with a regular gas block, H2 buffer, and M193, M855, and match ammo. I don't put garbage ammo in my rifle, personal preference.

I'm of the mind that an even better setup is an adjustable block AND the WAR receiver. Maybe even add the LMT Enhanced Bolt Carrier and a PRI Gasbuster for overkill. I say this because with an adjustable block and the WAR, you can fine tune the rifle for both modes. Gas block would basically be set and forget after some fine tuning to where you are using the least gas un-suppressed with the suppressor off.

Last, it's probably been said but you will not be cycling subsonics in 5.56. You'd be hand cycling them. .300 BLK can do it, but that's a completely different ballgame in terms of suppressor choice, barrels, etc.

I discounted the war because I dont plan to run it unsupressed often. It will be suppressed 80% of the time i use it so I dont feel theres a need for a quick adjust switch since I wont be constantly switching back and forth. However I do want it to run reliably unsuppressed as well for obvious reasons including the chance the suppressor is damaged in survival or something along those lines. Ive never used an adjustable gas block but if its truly set and forget then I may go that route and then if one day the suppressor is disguarded I can readjust. But I really plan on this rifle being suppressed most if not all the time. Any suggestions on gas block/ handguard that work well together and also allow reflex suppressor use?

Fair enough. I almost never shoot mine unsuppressed, but I like the option. If I didn't have a brake on the 12.5" it would get used without the suppressor more. Sadly I have to share with the Mk12 for now, as my Form 4 for my AEM5 isn't even submitted yet.

Okay, Reflex on a 12.5". In the case of the SPR/M4 and probably the Griffin SPR, the longest rail I could use was the 9.5" ones like the DD Mk18 rail. Since then, Geissele released their 9.5" SMR Mk4, and Centurion their 9.5" CMR in very close dimensions to the Mk18 rail. So take your pick of the three, but if I did it again I'd go Geissele. The CMR has fitment issues with many gas blocks out there, and to my knowledge any adjustable block currently on the market would need the bottom milled/filed/dremeled down to get clearance. That includes the SLR and Syrac blocks. The CMR is only guaranteed to work with Centurion's own low-pro. Google "CMR gas block" and you'll find threads/posts on many forums about the issue.

Those are some of the longest you could probably run. You MIGHT get away with a 10" rail depending on who makes it, as some are actually shorter/longer than what is listed.

So other than the handful of 9.5" rails, you can run any 9" "midlength" free-float rail and have more than enough room. The gas block will be covered, so consider rails that are easy to install where you can fire the rifle without the rail installed and make your gas block adjustments. Then just install the rail, and forget about the gas block! Troll around Rainier Arms, Weapon Outfitters, BCM, or one of the many other AR parts places and look through their rails. If it's a 9.5" or below, you should be GTG. 10" will be questionable unless it has a large internal diameter and some of the suppressor can actually fit inside.

Man you are more helpful than you know. Im pretty confident now in this build. I have two more questions.

1. Where can I find an spr/m4 suppressor in the u.s. or is it not sold any longer?

2. Does the bcm bolt carrier group ive chosen work well with this build? Are there bcg's that work better than others for this kind of setup?

Actually one more question also....

3. I know you recommended an h or h2 buffer but will my carbine buffer work or should I get an h?

1) SPR/M4 is NLA, dead, defunct. Your best option if you *really* want something like that is the Griffin SPR, which is carried by Silencer Shop. HOWEVER, I sincerely recommend the AEM2, or one of the other AEM suppressors because again, your 12.5" with the Griffin or SPR/M4 will become a long, bloated heavy rifle. Learn from my experience, it is worth it to find a dealer that can get you an AEM2. You can always email Allen Engineering directly, they can not only help you make sure your chosen barrel has the correct M4 profile at the muzzle (not the 203 cuts, that's different), but they can probably find you a dealer to order through. ADCO is another dealer/distributor/gunsmith 1-stop shop who are in Ohio? If you can find a Class 3 dealer near you that will do NFA transfers (usually for fee, $50 where I am), then ADCO can supply the can, transfer to your dealer, where you then do the Form 4 and wait the ~6+ months.  OH, and the AE series of cans might not be the lightest, but they are built like damn TANKS. It will truly be a lifetime investment, and they are not nearly as rough on the wallet as most QD cans are.

2) BCM BCG works well on ANY build! They have a solid rep for a reason. The only reason I mentioned LMT's Enhanced Bolt Carrier (just the carrier) is because it has some enhancements that work very well with suppressors in terms of regulating the carrier's speed. They are pricey, and not a "need" for your plans.

3) Honestly, you could probably get away with a Carbine or an H. If you tune the gas to work with a carbine buffer, then you should be using less gas, have less blowback, etc. At one point heavier buffers were a bandaid of sort for rifles that were way overgassed, ie. there was so much gas that the cyclic rate of the bolt carrier was excessive to the point of inducing malfunctions and increasing wear unnecessarily. The heavier buffers held the bolt in battery (locked forwards) longer, and slowed down the cyclic rate. This was especially aparent in SBRs that had monster gas ports. Adjusting your gas combats the issue at the source, meaning you should be able to use lighter buffers. An H buffer should be a good balance that will give you plenty of mass to make sure the rifle can function when it gets dirty. If that becomes a problem, just tweak the gas further to help when the rifle gets really dirty (which it will).

Are you locked in on a BCM barrel only? There are a few other options out there for 12.5" barrels, in terms of barrel profiles, chromed or melonite/QPQ, different chambers, etc. Ballistic Advantage makes some really nice barrels for not a lot of beans, and they're very accurate as well (especially the stainless ones, but I don't think he does them in 12.5"). The DD 12.5" CHF barrel is also another very good choice, I've had absolutely no qualms with mine. White Oak has a 12.5" with a heavier contour if you want a short match-grade barrel, but then you're back to adding weight.

I reallycouldn't decide between BCM and dd. I also couldn't decide between 1/7 and 1/9. I decided on going 1/8 twist with th bcm which is the only 1/8 I could find but then noticed it was stainless not chrome lined. This being a do-it-all survival rifle I prefer the chrome lined for longer barrel life and faster cleaning and hopefully less build up between cleanings especially with it being suppressed. I am definately open to the dd barrel and might actually go that route. Reason I chose bcm ovee dd was mainly cause the bcg will be bcm.

You don't actively need to restrict yourself to keeping the barrel/bcg manufacturer the same. Sure, it's a good idea to help eliminate the extremes of tolerance, but when you are talking about DD vs BCM, both have solid QC and tolerances.

You honestly won't see much functional difference between a BCM Standard 12.5" Govt, BCM CHF 12.5" Govt, and DD 12.5" Govt. The SS barrel will be noticably heavier, which I'd recommend against for a real "EOTW" kind of rifle. If you honestly think you're going to be humping around a lot, the weight gain of going to a heavier profile like the BCM SS is something you will notice. Even my Gov't profile DD feels hefty with the Mk18 rail, a light, and the suppressor mounted. I really do think that going to the AEM2 would significantly change how the rifle handles, and even more if I switched to a Centurion CMR. If you are fine with sending your upper off to get an adjustable block machined, then the CMR might really fit what you want to do. Very light, strong, slim profile, doesn't look like it mounts shelves .

One last concern, I don't believe the BCM standard or CHF barrels come dimpled for a gas block. My DD definitely didn't. The Ballistic Advantage barrel I linked *should*, but I could be wrong. With that in mind, you'd want to pick up one of the barrel dimpling jigs from BRD, I think BCM and Brownells stock/sell them. Or, send it off to have it assembled. If you did that, ADCO could hook you up with making sure the barrel is GTG for the AEM2, shave an SLR/Syrac gas block down, and mount it all up.

Ok so I did some research on the cmr and called up some local gunshops and machine shops. Im gonna have to turn that one down. Only reason being the gas block issue. Youve sold me on the adjustable gas block and im afraid that will be an issue. From the pics on centurions site of their cmr specific gas block it looks like most is shaved off the bottom. On an adjustable i feel the top is larger than non adjustable which worries me with machining capabilities. And I do not want the gas block exposed with a hole in the rail. So after some more browsing around I think im gonna go with the bcm kmr 9" which is actually 9.4" (like you said, they dont advertise specific length). The kmr is magnesium based and only 3.8 oz! Like a feather! And will work with an adjustable gas block. So im pretty decided on that and will probably go bcm adjustable gas block also. Still havent decided on a barrel but the ballistic advantage sure is tempting with that price. How comparable is the ballistic in terms of longevity, reliability, and accuracy compared to bcm and dd? I by no means want to cheap out on anything on this build. However ill definately save some money if its the same quality as said brands. Thanks again for the answers and support

Griffin suppressor that was suggested earlier




"Reflex" generally means any suppressor that recess or fits over the barrel, instead of directly on the muzzle.


 





AEM3 would be the AE equivalent to OPS's 15th Model.

I think the suppressor will be the hardest choice.... I really want to get the most suppression possible out of it while hopefully not putting too much extra length and weight on the end.

I know those two things work against eachother but im still hopeful. I cant find any videos or graphs for the aem2 and how well it suppresses. Decisions....

 
Doesn't really matter. You can go by technical data all day long on whats more quiet.



In the end, your ear won't tell the difference.



 


I have an OPS INC 12th Model (AEM5 equivalent) - 8.5" long, recesses about 2" over the barrel and a KAC NT-4 - 6" long and mounts to a flight hider.


The both sound equally the same.




Even my M110 suppressor (little over 14" long, recess over the barrel about 6") sounds about the same as my .223 cans, even though I'm slinging .300 Win Mag rounds though it.


 

So basically I should go with a shorter one then is what your saying? Idk ive heard that the difference in suppression from the ops 12th and 15th is pretty noticeable

About less than 5db difference, 15th Model being slightly louder

 

After just watching this clip I can see your point.

http://youtu.be/ePhVVeTE2Cs

So now to choose either ops 15th or aem2?

What are the similarities and differences or are they basically the same since they are both designed by same guy?

 
OPS INC is no longer in business. Allen Engineering worked closely with OPS INC and took over production after the owner of OPS INC died.






The AEM2 is equivalent to OPS INC's M4-M suppressor, which is smaller than the 15th Model/AEM3.






The AEM3 is equivalent to OPS INC's 15th Model



 




The OPS INC 16th Model (AEM4) is kind of like a hybrid between the 12th Model (AEM5) and the 15th Model (AEM3).


The mounting profile is the same as the 15th Model, but has the same baffle stack as the 12th Model. At least that's how it was when OPS was in business. I am not sure if Allen Engineering has changed anything.


 

Good info dangerdan! Thanks alot. I guess allen engineering it is. Im not very interested in griffin. Cant justify paying the extra $ when ops/AE has a solid reputation. Seriously thanks for all the help people

 
Be prepared to wait, although, ADCO has the AEM4 in stock.


 

Can you tell me what rail is on the top rifle? Is that a LaRue? Thanks

It is. Looks like the 11" Gooseneck rail.
http://www.laruetactical.com/larue-tactical-11-handguard-sbrs-gooseneck-lt15-11

If you want a short handy AR I'd get a mini suppressor, they are all loud, 10 db is noticeable difference but they are all still load. for your intended use, I'd sacrifice 10 dbs for 5 inches any day of the week.

Hate to throw another option your way, but a 10.3" gun with a mini suppressor is gonna be 13", and the right ammo through a 10.3 gun is plenty effective out to 250 yards.

Im definately set on the 12.5". With a 10.3" I just dont think ill get the suppression I want and to me buying a suppressor and paying the tax stamp wont be justified in that case. Not to mention the loss in velocity and fragmentation range. Also I am absolutely going to go with an AE suppressor just havent decided which one. Im gonna try and contact them for some advice and conparison I think.

I hate to keep asking more questions but this morning my buddy started mentioning piston driven systems.

I know close to nothing about these and would like to know the pros and cons of going that route with this build?
.... would piston driven be a more reliable option for running suppressed with this build?

Sorry for dragging this thread on but so far you guys have helped a ton

Please post any links to any info you find on the aem2,3,4etc...as far as sound reduction. I can't find squat. I'm on the fence about whether to get an AEM3 or 4 or a Yhm phantom m2. I already have a phantom in .30 cal which use the same mounts so no extra mounts needed.

Yhm phantom:  $543
Mount StyleYHM Phantom QD Mount (included)
Length6.875?
Diameter1.5?
Weight18.5 oz
Build Material316L Stainless Steel, Inconel 718
Sound Reduction39 dB (From Manufacturer)
Full-Auto RatedYes

AEM3: $650 +~$100 for mount (specs taken from ops inc website "15th model")
Caliber5.56mm / .223 caliber
Diameter1.5 inches
Length past brake3.5 inches
Length past muzzle4.75 inches
Overall length7 inches
Weight17 ounces
ConstructionFusion welded 300 series stainless steel

So it looks to me that the yhm will be $200 less for ~ 2" longer length, 1.5 oz heavier, but no info as far as dB comparison.

I actually just did some reserch on pistonvs gas impengement and decided on sticking with gas impengement for a few reasons.

1. Gas runs quieter than piston suppressed
2. Parts for gas system are more plentiful
3. Gas system is cheaper (depending on brand, etc)
4. The gas can be tuned to run with specific setups with gas system
5. Not sure how anything besides the barrel, sight in, optics and shooter affect this but apparently piston systems are less accurate. (Not sure if i believe this one but its been stated)

So gas system with adjustable gas block and dimpled barrel is the route im gonna go. Wont be till probably mid summer when I finish this build but ill be sure to post pics and range reports when I get it finished.

Also I am definately goin with an AE suppressor. Just havent decided which one

I'm not sure if AE changed anything, but when I bought my OPS, it came with mounts

According to the AE site, the can doesn't come with a mount.

There was a thread on Silencer talk where Ron Allen stated that the 12th Model (AE5) was only about 1 db quieter than the 16th model (AE4) IIRC.

 

What im wondering isnt so much overall length of the suppressor. Im worried about length pasth the barrel.

Does anyoe know the lengths past the barrel of the 12th, 16th, and 15th or their AE couterparts?

I wont be using an m203 so if I can use one of the longer versions (12th or 16th) and it will only add length on the barrel and not past the barrel i will def go that route

I emailed Ron the other day about the AEM2 and it needs 2.2" of barrel behind the muzzle (iirc) for the mount...so the other models that use the same mount I assume need the same clearance.

This is a DD 12.5" barrel and an OPS 16th model. Hope it helps, if you have any questions I'll try to answer them. Ron is awesome and you won't be dissapointed. Before I got the 16th model I shot one side by side with an SPR-M4, 762SD, M4-2000, etc, etc, and I still think the 16th model sounds better, The Ops cans just have a different tone to them.  








Sorry for the crap cellphone pics

Hope I dont look really stupid asking this but where exactly is it measured from with from the brake and from the muzzle measurements?
Just wondering is the from the muzzle measurement measured from the end of brake to end of supressor or from where the barrel and brake mate when its threaded on? Again, sorry if this is a stupid question. Just want to make sure ll my math is right before orderring parts

And kavon im thinking I will probably go with the aem/4 or 16th also. Thanks for pics and measurements. What length rail is that? Id like my rail to come right to my suppressor since im not doing an m203 if possible.

Sorry, here's a pic that shows the end of the barrel in relation to the muzzle break


Here is a different muzzle device, this collar just rests on the shoulder before the threads on the barrel. With this, I don't need to worry about a barrel having the correct step.  Also, Smith Vortex.




It's a Carbine length DD Lite rail.  I wanted a pseudo mk18 clone but don't really love the KAC cans or rails. You can easily get a rail to do that.  I would suggest asking Steve or someone at ADCO about what combo they suggest.  They are a stocking dealer of the AE cans and build uppers.

Going off of Kavons pics, it looks like a 9" rail will be the max you could fit on a 12.5" barrel. A 10" rail may fit if it's actual length is under 10". The BCM KMR 9 actually measure 9.4" on the sides, 3 o'clock and 9 o'clock positions on the rail, which will leave a small gap between the end of the rail and the collar. I should have my BCM kino w/kmr9 Monday so I need to figure out what can I want. Leaning toward AEM3. I'd be sold on it ifi could find some damn dB info.

Not exact db info but I posted a video link earlier in the thread that shows comparisons with the ops 15th/aem3 vs ops 12th/aem5 along with others. Check it out.

Also from the pics posted earlier of the green/black 12.5" with the larue gooseneck and ops 15th/aem3 suppressor makes me think a 10" rail that is truly 10" will come right to the suppressor. The larue gooseneck (correct me if im wrong) is 10" at 3,6,and 9 o'clock with the 12 o'clock rail stretching to 11".

Yup again on the Larue Gooseneck.

I'll say this guys, as far as DBs and such. When I'm at the range, or even out on property shooting, I still use at least foam plugs when suppressed. Surefire in-ear work better. At anything but a private range where you're the only person, you'll still want them thanks to your neighbors. If you're out on property and tempted to shoot without ears, I'll say that even my SPR/M4 on an 18" barrel is at the border of "uncomfortable" without ears in. It's something that would be acceptible if I were hog or deer hunting, ie. only short strings of fire and then nothing, but not for a course or all day shooting session.

If you're thinking in terms of SHTF or anything similar, then even a short can that DBs a few higher than a longer can is still better than any length rifle with just a flash hider, or especially a brake. I'd go with the shortest of the AEM, because I think you'll find the weight and length savings the most beneficial. You will still have the tactical benefits of the sound suppression, and it will still be easier on your ears than a 16" rifle with no can. Unless you went .300 BLK subsonics for absolute lowest DB you aren't going to have comfortable levels of suppression with supersonic 5.56 ammo, but even then with BLK you'd be in a bind in a SHTFEOTWAWKI scenario due to the inability to pick it up as a common round off non-surviving folk.

Yeah I've watched the video several times, that's why I'm still interested in the AEM. But all we can tell from that video is that they get progressively quieter and the 15th and 22nd sound "good".  I'd just like to see some data...or a video of the AEM3 vs another known good performer.

I own two reflex cans: OPS M4S and SF FA556AR. I won't be buying more and the M4S is sold pending funds. Great cans but I'm doing muzzle mount from here on out. I like the longer rails I can use with them and reflex cans are heavier than newer cans. In your position I would skip the adj gas block and get a compact can like the SF Mini that is known for minimal backpressure.

If you do settle on OPS/AEM get the M4M or 14th for your SBR and add a 16th later for an SPR.

Don't get hung up on decibels they are all too loud to shoot regularly or in confined spaces without ear pro.