I've been a big fan of these cans since I first saw one on a Mk 12 way back when. Haven't seen a thread dedicated to them, so thought I would create one! Anything you spy that is incorrect, let me know.

The Firearm Blog article on Allen Engineering written by our own @goloud

5.56 Cans
Ops Inc cans
Ops Inc Family pic courtesy of @The_Accuser. Top picture from right to left: M4S, M4M, Model 14th, 15th, 16th and 12th:


Ops Inc 3rd Model
1989 Panama (Paul Howe on far left)
 

Mid-90's in use by Delta (photos found by @10Point3)

1990-1991 Gulf War:

 



1992 joint training w/ SAS in Hereford

1993 Somalia



Possible 3rd model as used by Craig "Sawman" Sawyer (h/t to @Augee and @bigbore for detective work)

More recent photos of 3rd model (found by @MDStroup):


Original alignment collar (courtesy of Ron Allen (@k31user), owner of Allen Engineering and long-time maker of cans at Ops Inc)

Diameter: 1.5 inches
Length past muzzle: 5 inches
Overall length: 10 inches
Weight: 24 ounces
Construction: Fusion welded 300 series stainless steel
Endurance: Meets SOPMOD objective of 30,000 rounds under various firing schedules.
(Note: Currently these devices have surpassd 90,000 rounds operational use without failure)

M4-S
 

Caliber 5.56mm / .223 caliber
Diameter: 1.5 inches
Length Past brake: 1 inch
Length past muzzle: 2.25 inches
Overall length: 4.5 inches
Weight: 11.2 ounces
Construction: Fusion welded 300 series stainless steel
(Note: Currently these devices have surpassd 90,000 rounds operational use without failure.)

M4-M MBS
 


@pistolpete's 12.5" upper with M4M


Diameter: 1.5 inches
Length Past brake: 2.5 inches
Length past muzzle: 3.75 inches
Overall length: 6 inches
Weight: 14.6 ounces
Construction: Fusion welded 300 series stainless steel
(Note: Currently these devices have surpassd 90,000 rounds operational use without failure.)

12th Model SPR MBS 5.56
Mk 12s
 

Matt Axelson's with James Suh (RIP ) Mk 12 Mod 1



@Rogue4's

Mod Holland's (h/t to @Glass1, @18E3V, and @Nikiel09):

 




Diameter: 1.5 inches
Length past brake: 5 inches
Length past muzzle: 6.25 inches
Overall length: 8.7/8 inches
Weight: 21 ounces
Construction: Fusion welded 300 series stainless steel
Endurance: Meets SOPMOD objective of 30,000 rounds under various firing schedules

14th Model CQB MBS

Diameter: 1.5 inches
Length past brake: 3 inches
Length past muzzle: 4.25 inches
Overall length: 6.5 inches
Weight: 15.5 ounces
Construction: Fusion welded 300 series stainless steel

15th Model CQB MBS


15th model? In use by Canadian SOF




Diameter: 1.5 inches
Length past brake: 3.5 inches
Length past muzzle: 4.75 inches
Overall length: 7 inches
Weight: 17 ounces
Construction: Fusion welded 300 series stainless steel
Endurance: Meets SOPMOD objective of 30,000 rounds under various firing schedules.

16th Model CQB MBS


@BookHound's 16th Model:

@pistolpete's 16th Model

Diameter: 1.5 inches
Length past brake: 4 inches
Length past muzzle: 6.25 inches
Overall length: 8.5 inches
Weight: 19 ounces
Construction: Fusion welded 300 series stainless steel
Endurance: Meets SOPMOD objective of 30,000 rounds under various firing schedules.
Allen Engineering (AE) cans

AE22

Length: 8"
Weight: 20.1oz
Finish: Black Oxide
Lifetime Warranty

AEM5
@RTUtah's:

Length: 8 7/8"
Weight: 21oz
Finish: Black Oxide
Lifetime Warranty

AEM4

Caliber: 5.56
Length: 8.5"
Weight: 20oz
Finish: Black Oxide
Lifetime Warranty

AEM3

Length: 7"
Weight: 18.2oz
Finish: Black Oxide
Lifetime Warranty

AEM2

Length: 6"
Weight: 15oz
Finish: Black Oxide
Lifetime Warranty

Which AE can is roughly equivalent to an Ops Inc Can?
AE22 = Ops Inc 3rd model 5.56
AEM5 = Ops Inc 12th model SPR MBS
AEM4 = Ops Inc 16th Model CQB MBS
AEM3 = Ops Inc 15th Model CQB MBS
AEM2 = Ops Inc M4M

Is it possible to have a custom collar made for a 16” OPS profile barrel that’s been cut down to 15.1”, or does it need to be recontoured all together?

Ron can make a custom collar for damn near anything. When you say Ops profile, do you mean Ops 12th model SPR or M4 MBS profile? There are two specs.

It’s the 16” SPR profile for the 12th model/AEM5.  I shot Ron an email to see about the collar before I go and have the barrel recontoured.

I can't remember where I got it, but I have a collar that indexes off of the shoulder. No step on the barrel needed. He could probably make you something similar.

Most likely I can make a collar for it. Would need length to step, diameter before step, and diameter after step.

RonA

Ron,

Could you make a collar for a barrel that doesn't have a step? I picked up a Ruger American Ranch that I'd love to use with an AEM5 I've had sitting for a bit.  I'd like to avoid having the barrel profiled if I can.

I had the exact same question!

Maybe. Depends on the barrel diameter behind the thread shoulder.

I'll have to take some more accurate measurements a little later, but it's .6725 at the shoulder and gradually increases to .700 around the 2" mark.

Attached File


Is there a problem with having this much of the muzzle inside of the brake?  I have a WOA SPR barrel and if I used the supplied crush washer or extra shims I was getting around 12-13 complete rotations before the van was seated against the collar.  I am now getting 8-9 rotations which I thought was more appropriate.

I had the same problem with my Criterion barrel. I just shimmed it out until it was flush with the ports. Once I did that, everything was the perfect distance ( 2.05" till the start of the taper for an M4 MBS ).

My WOA SPR barrel required a custom collar from Ron to work properly.

Wrong collar. Install should not look like that. needs either a crush washer or thick shim to move the brake out so inside edge is somewhat flush with end of barrel.

RonA

@k31user

Ron, I sent you an email.

I saw 2 pages back discussing a rifle length gas 16". Will the AEM5 fit if using the Spike's gas block/collar?

No. AEM5 requires more clearance than the AEM3.

So what's the minimum length for a rifle gas and the AEM5 using the Spike's block?

I know the AEM5 is listed at 3.2" needed. Looks like the AEM3 needs 2.7" (your setup correct?). So we talking 16.5" minimum?

The Spike's block is 1.25" in length with the taper being the 0.25". I don't know why I struggle so much with the sizing of the AE cans.

2.2" for m4 style, 2.7" for AEM5.(That's with a custom collar that only goes back far enough to mount the suppressor). The rear of the suppressor will sit 2.17 behind bare muzzle on an M4 type, and 2.62 back on an AEM5.

Excellent. Thank you for the help Ron!

So it looks like a 16.7" would be about the shortest you could go using the Spikes block/collar.

A 16" rifle SPR would have 3.25" from the gas block journal to bare muzzle as Spyhawk showed 2 pages back. If you need 2.70" for the AEM5 that leaves you with 0.55" for the gas block/collar combo which I have measured at 1.25".

ETA: The AEM5 is my favorite rifle can that I own but I kind of wish I had the 4 for a hair more flexibility in working barrel length.

So, I don't know if you are into SBRs or pistols, but I always thought it would be awesome to do a 13" middy with an AEM5 and the spikes collar or spikes gas block. Spikes claims they are the right size for 10.5" carbine gas M4MBS cans, so add .5" for the AEM5 and then add 2" for mid-length gas and you get 13". That would be sweet. You would need an odd 11" handguard though. Or go over the can.

That would be a nice setup. I'm currently rocking a 15.x" Holland type build with the AEM5.

Looking at cutting down a Larue Stealth for the AEM5 to be flush with either a KAC medium FF RAS or a midlength URX 2.  Anyone have some pics of a setup like this?

Have a 14.5 stealth barrel, 12 stealth barrel, KAC midlength, and KAC too long. can take pics tonight.  Have been wanting to do a build like that for a while.  Also have KAC MRE and a BA barrel.  Will probably leave that 16" instead of going to 15.x. IDK, out of money now, lol.

Has anyone tried any of the AE cans on the SCAR 16? The AEM5 in particular.

Just dropping this as a PSA, but dvor.com has PRI Mk12 Mod0 handguards and sights on sale.

Will the Spike's Tactical Silencer Combo mount work with an AEM5 instead of having a barrel reprofiled?  They have one for a .720" and .750" barrel diameter.

I’m pretty sure Spikes uses the smaller AEM2/3/4 mounting dimensions on their suppressors.

If the spacing between the gas block journal and muzzle is correct then yes. That combo is designed to get the AE cans on shorter barrels where there normally wouldn’t be room for a gas block and collar.

I laugh every time I fire the first few rounds down range with this can. So great.

Anyone know if an AEM5 will fit on a 12.5" barrel with the MK18 RIS?  Looking for a flush fit with the rail.

IIRC, that's a perfect combo. I can double check Monday.

As some of you know, Ron A. has been generous enough to allow me to use one of his B&K 2209 dB meters for the past six months.

I’ve got two AEM5s and two MK12 uppers coming for a unique review. Both will be tested alongside a SureFire SOCOM RC2 as a control. The only other 5.56mm silencer I have for comparison is a Form 1.

I’ll let Ron examine the data as it comes out and he can tell you about the AEM5 and the MK12 combination when he’s ready.

!!!!

Pumped to see what your results are! Please let us know when you guys have data.

Cool!

Had a conjugal yesterday.



https://www.instagram.com/korwerks/

That is gorgeous. 16”barrel with 13.5” rail? AEM5?

Looks longer than an AEm5

Thank you!
Yep you got it. AEM5 is going on month 8.

Maiden voyage shooting the AEM5 on my MK12 this past weekend. This can is incredibly quiet. I am impressed!



MK12 MOD JUAN

I like em black. Just like my coffee. Looks nice and simple.
RonA

Thoughts on a build like this with an AEM5? I'm kinda looking for something a little different. Thinking I could tuck the can up close to that rail.

If anyone has any builds like this, please share!

First time is the best. Nice Mod Juan!

That's a good way to put it. I'm with you guys!

Any word on this combo? I have a Geissele MK14 9.5" that recently lost its barrel to another build. The MK18 RIS and MK14 9.5 are roughly the same size and I was thinking about doing a 12.5" AEM5 build with it.

You'll be good with that. It was about an 1/8" gap with the MK18 RIS II and will be a little more with a 9.5" Geissele rail. This is assuming the 12.5" barrel is actually 12.5" from bolt face to muzzle.

Is it possible to get a AEm5 sized .277 bore?

Yes.

I had been thinking about a build with the URX II 10.75" and flush AEM5.  I think you just convinced me with this picture.

Attached File


Attached File