Clipping a 5.56 Suppressor worth the accuracy and POI issues?

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malneyugnfl
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Clipping a 5.56 Suppressor worth the accuracy and POI issues?

Post by malneyugnfl »

Hello. This is my first post, so forgive my ignorance.

I brought my newly built 5.56 suppressor to a 50 yard rifle range and tested it out. At 50 yards, I was getting a single ragged hole group with a Red Dot Sight and no noticeable POI shift. However, the rifle w/suppressor was louder then a gentleman's ruger 10/22 that was being shot right beside me.

The baffles on my suppressor build are unclipped. So my question is whether or not clipping the baffles on my suppressor going to make enough of a noticeable difference to make a 5.56 sound quieter then an unsuppressed .22lr rifle? In your opinion, is the decibel decrease of clipping baffles worth the POI shift, possible decrease in accuracy from misaligned clips, and the extra machining time?

By the way, I'm just an amateur with no ability to use a lathe, a dremel, a milling machine, or a welding machine.

These are the specs on my suppressor:

1. 1.5" Diameter tube that is 7.8" long
2. Eight Cone baffles that are 60 degrees. The cones are evenly spaced .668" apart.
3. The blast baffle is just a cone that is drilled .35" to give room for the bullet to stabilize.
4. The other cones and the end cap are drilled .281" or 9/32" in diameter.
5. Blast chamber is about 1.75" long.
6. Total weight is 21.3 oz. It's heavy but that's okay as it will help dampen the barrel harmonics.
7. No clipping so far.
8. Direct thread
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Re: Clipping a 5.56 Suppressor worth the accuracy and POI issues?

Post by ECCO Machine »

yes, clipping will make a big difference. It's what disrupts laminar flow; without them, the high pressure gasses just follow the bullet out the front of the can relatively uninhibited. The clips create a cross flow that disrupts the laminar flow, generates turbulence, helps the baffles do their job. You can get away with no clip on a rimfire can, but it's pretty essential for everything else.

The specs you've provided indicate a can that should give pretty decent performance in terms of size, baffle quantity and spacing.

POI shift can be caused by many factors aside from the clip, although misaligned clips certainly can be detrimental to accuracy. Most notably, POI shift on rifles is a change in barrel harmonics resulting from the weight on the muzzle, causing the oscillation to change and the bullet to exit at a different orientation of the muzzle. That's why so much of the focus in precision shooting is consistency; a 20 or 30 FPS change in muzzle velocity causes the same phenomenon of bullet leaving muzzle at a different point in the oscillation cycle, thus changing POI. So precision shooters weigh each case, bullet and powder charge, pay attention to lot numbers, carefully check seating depth and play with load development until they find the most consistent combination for their rifle. Likewise with suppressors, adding a can, going to a can that is dimensionally different from the one you sighted with, or removing and reinstalling one that doesn't square up exactly the same every time will cause a shift. That's why precision cans such as TBAC use a taper mount that provides much more consistent alignment than direct thread or QD types.

Once you clip, if you're not welding or creating features on the baffles that keeps the clips aligned, you'll need to use an alignment tool of some sort. A simple one to do with your aperture size is something like 1/4" key stock with 2 opposing corners ground down. A little oil or light grease on the end cap to keep it from twisting the baffles and binding up on the rod.

The type of clip you should use is a subject of much debate, but I personally like the radiused asymmetric for rifles, which is an industry standard. On a 5.56 can, I have .275" bore and do a 1/8" diameter clip .150 deep, the face of the clip perpendicular to the baffle cone on that side.
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Re: Clipping a 5.56 Suppressor worth the accuracy and POI issues?

Post by malneyugnfl »

Thanks for the in depth reply!

1. So the industry standard is asymmetric and radiused. You use a clip that is 1/8" diameter and .15" deep. Do you use a milling machine to do this with precision? If so, I might have to take a machining class at a community college somewhere to learn the right way and to also use their equipment.

2. Also why is asymmetric clipping an industry standard? From what I've read so far, asymmetric clipping where all the clips are aligned down the stack seems to be the quietest, also but causes the most POI shift. My feeling is that in a market where a sale will be won or lost based mostly on the decibel readings without considering other factors.... Manufacturers just go with what is quietest because that's what makes the sale.

3. Why not use Dual Hybrid Clipping? Correct me if I'm wrong but it seems that this type of clipping would make it unnecessary to have to align the baffles in the same orientation in order to keep a consistent rifle zero. I'd like to keep this suppressor pretty dummy proof if possible and still allow it to be disassembled.

4. I've looked at a cutout of the Surefire Socom 556 suppressor that won the military contract. It looks like they don't clip their baffles. In tests I've watched online, it seems to be one of the louder cans on the market, but based on the design and their marketing... I would think there would be less worries about POI shift or accuracy issues because of the clipping. Why do you think they decided to have unclipped baffles and to use baffles that were rounded and not so steep?

5. Finally, if you don't mind. Do you have a decibel reading difference between an unclipped suppressor versus a clipped suppressor with everything else being equal?

Thank you!
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Re: Clipping a 5.56 Suppressor worth the accuracy and POI issues?

Post by ECCO Machine »

malneyugnfl wrote:
1. So the industry standard is asymmetric and radiused. You use a clip that is 1/8" diameter and .15" deep. Do you use a milling machine to do this with precision? If so, I might have to take a machining class at a community college somewhere to learn the right way and to also use their equipment.
Yes, a Lugun FTV-2 with dedicated fixtures I've made for each baffle diameter.
malneyugnfl wrote:2. Also why is asymmetric clipping an industry standard? From what I've read so far, asymmetric clipping where all the clips are aligned down the stack seems to be the quietest, also but causes the most POI shift. My feeling is that in a market where a sale will be won or lost based mostly on the decibel readings without considering other factors.... Manufacturers just go with what is quietest because that's what makes the sale.
It's a standard (not necessarily "the" standard, but very common) because it works. Not everyone uses asymmetric. AAC has their own breed of oddly clipped polygonal baffle apertures. I've done symmetric as well, such as my Five By Five and Leviathan 5.56 critters. The truth is other design elements have a lot more to do with SPL reduction and POI shift.
malneyugnfl wrote:3. Why not use Dual Hybrid Clipping? Correct me if I'm wrong but it seems that this type of clipping would make it unnecessary to have to align the baffles in the same orientation in order to keep a consistent rifle zero. I'd like to keep this suppressor pretty dummy proof if possible and still allow it to be disassembled.
I've hardly played with it since asymmetric radiused and symmetric square clips have worked very well for me. My theory, which I've yet to test by building a sloppy can, is that it's popular with the F1 crowd because it's more forgiving of lower precision that results from stacking tolerances with the solvent trap parts. If your D cell is 1.360" ID +.005/-.002 and your cup is 1.355" +.002/-.005, you could end up with a really tight fit, or one that has up to .015" diametral clearance (I don't actually know what the tolerances for each mfr. of those parts is, just putting up some common tolerance numbers for ID & OD combos). Add in hacksaw cut and filed spacers separating skirtless baffles, you could end up with apertures that are not well aligned laterally or longitudinally.

I really couldn't tell you how critical is is to align the "DHC" baffles. The only clip I use that I don't worry about alignment with is a half moon in my Ocelot, Ocelot Micro and Ocelot M rimfires.

Image
malneyugnfl wrote:4. I've looked at a cutout of the Surefire Socom 556 suppressor that won the military contract. It looks like they don't clip their baffles. In tests I've watched online, it seems to be one of the louder cans on the market, but based on the design and their marketing... I would think there would be less worries about POI shift or accuracy issues because of the clipping. Why do you think they decided to have unclipped baffles and to use baffles that were rounded and not so steep?
I don't have much to offer you on this one, other than confirming that Surefire cans are indeed pretty loud. And heavy. And expensive. Before I became an 07/02, an 01/03 buddy of mine tried to get me to buy one of the SF 5.56 cans for my SBR. As soon as I picked the thing up, it was a quick "nope!". And I hadn't even heard it yet. Though I've not personally metered any SF cans, I don't need hard dB numbers to know they're not even really competitors in the game from a SPL reduction standpoint. I'm sure the durability is good (better be for all that mass!), but they are very underperfoming suppressors in my opinion.
malneyugnfl wrote:5. Finally, if you don't mind. Do you have a decibel reading difference between an unclipped suppressor versus a clipped suppressor with everything else being equal?
Only for .22 LR, and it was minimal. Like, different brands of ammo and different testing locations made more difference than the average between clipped and unclipped. Maybe one day I'll do a version of my limited production stuff with no clips just to test, but it would be strictly an academic venture, as I know it will be louder, and I'll have time & materials into a basically worthless suppressor, since all my rifle can cores are fully fusion TIG welded. I did do a test run of unclipped baffles in my Phoenix XLV, gave them four 1/8" ports instead (same number of cones, same profile). But I didn't meter it. It was noticeably louder. The standard Phoenix XLV is pretty much a K can at 1.375 x 7.0", and meters 138 with ball ammo. That unclipped ported baffle verison I'm sure was well into the 140s. It snapped my ears pretty good. The baffles in my Vorticis are ported & unclipped, but that thing is a whole different breed of can meant for lower at-ear SPL on blowback carbines & subguns, so it doesn't tell us squat about how it would pan out in a conventional configuration.
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Re: Clipping a 5.56 Suppressor worth the accuracy and POI issues?

Post by malneyugnfl »

Thanks for sharing your in depth experiences with suppressor building and for specific technical specs! I've learned alot and realized that if I want maximum suppression out of my build... As well as to work on other creative projects, I'll probably have to take a general machining college course to upgrade my skills. I'm an Engineer by profession so learning the physical execution of designs is probably a good thing.

Thanks for the lessons and have a great day!
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Re: Clipping a 5.56 Suppressor worth the accuracy and POI issues?

Post by fishman »

I'm just an amateur with no ability to use a lathe, a dremel, a milling machine, or a welding machine.
You dont have the skillset to use a dremel tool? Buy one and cut some s--t.
300 blackout form 1: http://www.silencertalk.com/forum/viewtopic.php?f=10&t=137293

5.56 form 1:
http://www.silencertalk.com/forum/viewtopic.php?f=10&t=141800&p=955647#p955647
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Re: Clipping a 5.56 Suppressor worth the accuracy and POI issues?

Post by ECCO Machine »

malneyugnfl wrote:I'll probably have to take a general machining college course to upgrade my skills
I'd never tell anyone to not further their education, but I suggest (and believe most here would concur) that your time and money are better spent doing some reading on machining, buying a couple of used machines and making chips. Machining theory is not rocket surgery, but there's a lot to learning how to actually make the cuts, including order of operations, work holding and knowing the machines and tooling you're working with. I have 6 lathes, and not a single one of them behaves like another. The theory behind turning a part on each machine is the same, but actually doing it with any given material is a whole other animal with machine rigidity, back lash, cutter & stock deflection. The big, deep jaws of the 13" chuck on my Rahn-Larmon behave very differently from the 8" chuck on my Hardinge or 4" on my 618. Taking a pass at .030" DOC will yield an entirely different actual depth and surface finish than a .100" DOC. Materials behave very differently cutting toward and away from headstock. Cutter profile, size, angle can make a tremendous difference. This is stuff that is best learned by doing on the machines you'll be using to make parts.
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Re: Clipping a 5.56 Suppressor worth the accuracy and POI issues?

Post by John A. »

malneyugnfl wrote: I brought my newly built 5.56 suppressor to a 50 yard rifle range and tested it out. At 50 yards, I was getting a single ragged hole group with a Red Dot Sight and no noticeable POI shift. However, the rifle w/suppressor was louder then a gentleman's ruger 10/22 that was being shot right beside me.
Your 556 is never going to be as quiet as a ruger 10/22 as long as you are using standard ammunition in it.

If you use subsonic 223, it probably will be similar in sound, but isn't likely going to cycle the bolt if you're shooting anything other than a bolt action. In which case, it will sound good and work properly.

No amount of baffle clipping is going to reduce supersonic crack. Just doesn't work that way unfortunately.

If you're using an AR, I guess you may could use a rimfire upper, or 22 conversion bolt like the ceiner or cmmg and use 22 rimfire through it if you want it to be as quiet as the 10/22.
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Re: Clipping a 5.56 Suppressor worth the accuracy and POI issues?

Post by ECCO Machine »

John A. wrote:
Your 556 is never going to be as quiet as a ruger 10/22 as long as you are using standard ammunition in it.
I got the impression that the 10/22 was not suppressed, which would be in the 140 dB range with a standard 16" tube and regular ammo. He should be able to beat that with a 1.5x8" can pretty easily.
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Re: Clipping a 5.56 Suppressor worth the accuracy and POI issues?

Post by John A. »

If it's made from one of those solvent trap cups, I don't think most of those are very effective in the first place. Even if you clip it, probably is going to do little to increase the suppression level enough to make a noticeable and worthwhile difference.
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Re: Clipping a 5.56 Suppressor worth the accuracy and POI issues?

Post by mr fixit »

For what it's worth, I just finished a can pretty close to what you describe. 1.625"OD tube, 7 baffles spaced .750, .750, .750, .625, .625, and .5 to end cap. My bore was .375" in all baffles and .410 in the end cap. I used the DHC clip on all baffles. Had a 16" AR as already sighted in, screwed the can on and had the same POI.
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Re: Clipping a 5.56 Suppressor worth the accuracy and POI issues?

Post by malneyugnfl »

mr fixit wrote:For what it's worth, I just finished a can pretty close to what you describe. 1.625"OD tube, 7 baffles spaced .750, .750, .750, .625, .625, and .5 to end cap. My bore was .375" in all baffles and .410 in the end cap. I used the DHC clip on all baffles. Had a 16" AR as already sighted in, screwed the can on and had the same POI.


Did you use a dremel tool to do the DHC on the baffles? My baffles are 17-4 PH Stainless Steel.

Also, now that I think about it, there were times where we both shot and the sound was almost equivalent... Even though we were separated by a wall. And yes it was an unsuppressed 22lr. Also I shot the suppressed 5.56 in my backyard and it was not that bad... Still kind of loud but with a deep tone.So I don't think the suppressor was complete crap.

I just bought a 22lr rifle so I can do an objective test out in the swamplands where I live.
This is stuff that is best learned by doing on the machines you'll be using to make parts.
Yeah. You're right about that. Hands on experience is mostly how I learn things. It's just that I don't want to spend money on a lathe or mill which I might not use very much and will just take up space. If clipping can be done with a dremel tool on 17-4 PH SS, I can buy a dremel tool. Otherwise, will go to a machine shop and pay $40/hr to use their equipment.
If it's made from one of those solvent trap cups, I don't think most of those are very effective in the first place.
I bought the SS cones off Muted Machine Works. They looked pretty similar in angle to cones used in professional cans.
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Re: Clipping a 5.56 Suppressor worth the accuracy and POI issues?

Post by malneyugnfl »

fishman wrote:
I'm just an amateur with no ability to use a lathe, a dremel, a milling machine, or a welding machine.
You dont have the skillset to use a dremel tool? Buy one and cut some s--t.
Will Most likely buy a dremel tool if it can mill into 17-4 SS. Will the tool overheat? Also, I checked out your 5.56 build. It looks beautiful. How does it sound? Do you have a DB reading? What is the tone?
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Re: Clipping a 5.56 Suppressor worth the accuracy and POI issues?

Post by fishman »

malneyugnfl wrote:
fishman wrote:
I'm just an amateur with no ability to use a lathe, a dremel, a milling machine, or a welding machine.
You dont have the skillset to use a dremel tool? Buy one and cut some s--t.
Will Most likely buy a dremel tool if it can mill into 17-4 SS. Will the tool overheat? Also, I checked out your 5.56 build. It looks beautiful. How does it sound? Do you have a DB reading? What is the tone?
Use a cutoff wheel on a dremel, you wont be cutting material away like a mill does. You'll be grinding it away.

Its got a really nice tone and its quieter than I was expecting. When shooting at 200 yards, the crack of the bullet coming from downrange is more obvious and attention grabbing than the muzzle blast. I have no idea how it meters, the equipment needed to get a true peak db reading of something like a gunshot is very expensive.
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5.56 form 1:
http://www.silencertalk.com/forum/viewtopic.php?f=10&t=141800&p=955647#p955647
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Re: Clipping a 5.56 Suppressor worth the accuracy and POI issues?

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John A. wrote: Mon Nov 19, 2018 1:53 pm If it's made from one of those solvent trap cups, I don't think most of those are very effective in the first place.
Surely you can't be serious John. Ive got 15 cans and I made 10 of them myself out of solvent traps. Almost all of them are as effective as anything I purchased on a form 4. No magic in this stuff or anything a licensed manufacturer can do that you can't do with some machine tools.
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Re: Clipping a 5.56 Suppressor worth the accuracy and POI issues?

Post by John A. »

There are many that are made from questionable materials, and there is also no magical good way to make a really quiet 556 can. So, I have to stand by my earlier comment.

I'm not saying that they all are junk, but I'm not saying they're all created equal either.
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Re: Clipping a 5.56 Suppressor worth the accuracy and POI issues?

Post by malneyugnfl »

So I finally did a double clip on the 5.56 suppressor. The sound reduction was definitely noticeable. There was no POI shift and accuracy still seemed to be excellent. Now what's noticeable is the noise from the port where the spent case is ejected. It's still really loud and not hearing safe.

I think that after a certain point of suppressor design, we reach the point of diminishing returns. Most of us are civilians, not military and we don't need to rapid fire over long periods of time. So the best materials aren't required. And if we are doing that, it's just better to remove the suppressor. Also, an AR-15 in 5.56 is still freaking loud. The speeding bullet is loud. The port noise is not hearing safe. And finally, the sound of the bullet striking the target, whether it's metal or flesh is extremely loud... For a suppressed 22lr rifle, the sound of impact on target is much louder then from the gun. There's a test on the YouTube channel Lone Star Boars. He measures the sound of impact about 130+ DB even for a 22.

It's fun to design the quietest suppressor possible with the most durable materials, but I think that we are just overengineering the wrong things after a certain point. Maybe focus on designing a quieter round(300 blackout) or a piece of kit that can lock and unlock the bolt of an AR-15 in place to prevent loud gas from escaping from the port, when you need to take that one really quiet killing shot. As for the sound of impact on target, there's really nothing we can do about that except to use different weapons.
Last edited by malneyugnfl on Wed May 27, 2020 10:45 pm, edited 1 time in total.
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Re: Clipping a 5.56 Suppressor worth the accuracy and POI issues?

Post by ECCO Machine »

malneyugnfl wrote: Mon May 25, 2020 5:15 pmNow what's noticeable is the noise from the port where the spent case is ejected. It's still really loud and not hearing safe.
You can get an AR carbine with the Stoner gas system ("DI"-not actually, but how most refer to it) below 140 dB with an adjustable gas block. Not by much, mind you, but to the point where it won't ring your ears. Should still wear ear pro, though, especially if you're going to shoot more than a few rounds. Rifle length gas systems I've generally found to have tolerable port noise without AGBs, but they can still benefit from it.

That said, you simply will not get any gas operated semi-auto rifle below mid-high 130 dBs at-ear if the gun is actually cycling. Most op rod guns will be over 140 no matter what you do with gas adjustment or low back pressure cans.
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Re: Clipping a 5.56 Suppressor worth the accuracy and POI issues?

Post by Hard_ware »

ECCO Machine wrote: Wed May 27, 2020 11:06 am
malneyugnfl wrote: Mon May 25, 2020 5:15 pmNow what's noticeable is the noise from the port where the spent case is ejected. It's still really loud and not hearing safe.
You can get an AR carbine with the Stoner gas system ("DI"-not actually, but how most refer to it) below 140 dB with an adjustable gas block. Not by much, mind you, but to the point where it won't ring your ears. Should still wear ear pro, though, especially if you're going to shoot more than a few rounds. Rifle length gas systems I've generally found to have tolerable port noise without AGBs, but they can still benefit from it.

That said, you simply will not get any gas operated semi-auto rifle below mid-high 130 dBs at-ear if the gun is actually cycling. Most op rod guns will be over 140 no matter what you do with gas adjustment or low back pressure cans.
Kailkey charging handle will turn semi auto into a single shot. I have a massive reflex suppressor back to the gas block 1.75” od 10 baffles , total length past muzzle brake about 4.5 “. It’s a very heavy beast but very quiet and never been bothered by gas from ejection port. It’s about 34oz. So it’s a beast but shoots good and had hogs run toward me at night while I was shooting them many times. Shows they had no clue where shots were coming from.
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Re: Clipping a 5.56 Suppressor worth the accuracy and POI issues?

Post by ECCO Machine »

Hard_ware wrote: Wed May 27, 2020 7:04 pm Kailkey charging handle will turn semi auto into a single shot. I have a massive reflex suppressor back to the gas block 1.75” od 10 baffles , total length past muzzle brake about 4.5 “. It’s a very heavy beast but very quiet and never been bothered by gas from ejection port. It’s about 34oz. So it’s a beast but shoots good and had hogs run toward me at night while I was shooting them many times. Shows they had no clue where shots were coming from.
I'd rather just run a bolt, pump or lever action that was designed to be manual action from inception and doesn't vent anything or force me to crane my head back to cycle it. I also have no use for >2 pound suppressors on anything that isn't belt fed or firing .50 BMG or larger.
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Re: Clipping a 5.56 Suppressor worth the accuracy and POI issues?

Post by Hard_ware »

I run it semi auto so no problem with loading next cartridge , shooting subsonic loads won’t cycle but are pellet gun quiet. But the >2lbs does suck.
Working on a light weight form1 at the moment and will definitely clip the cones.
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