Suppressor dissassembly


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bkjeffrey
March 4, 2010, 09:12 AM
Im looking at building my own suppressor for my AK, (with big daddy's permission). I have two different ideas that are both pretty simple. Both involve a steel shell with stainless steel k baffles. My question is how important is it that the baffles be removable for cleaning on a centerfire rifle? The easier way Im thinking of building it would be having it welded on both ends but that would mean I couldnt remove the baffles. Big deal? 7.62x39 ammo can get pretty dirty. If I couldnt take it down for cleaning I figure a good soaking in some caustic chemicals might help remove some of the carbon buildup every once in a while?

Thoughts?

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Sam1911
March 4, 2010, 09:23 AM
Conventional wisdom seems to be that centerfire suppressors really shouldn't need to be dissassembled for cleaning but rimfire ones probably should be.

Those ultrasonic cleaning bath devices do a pretty good job from what I've heard. So does soaking the can in Kroil or a solvent of your choice.

-Sam

bkjeffrey
March 4, 2010, 09:38 AM
yea, thats what Im thinking too. I guess Im just looking for verification. Im just worried about the dirt surplus Ak ammo out there. And some of its corrossive too.

Sam1911
March 4, 2010, 09:43 AM
The corrosiveness would be the easy part. Just wash the can well with hot water (maybe heating the can gently in the oven afterwards to make sure all the water evaporated) before oiling and storage. Of course, there's always a risk of not getting all of the salts rinsed out of the nooks and crannies inside a suppressor -- and then having the can rust through after a couple of years. That would suck.

Hmmm... I could go either way on that. I'd probably go ahead with a sealed can that I was making myself, knowing that I wasn't out a thousand bucks. But I'm kind of picky about cleaning after corrosive ammo so the threaded can might be tempting.

Why could you not make the whole can stainless? That would ease SOME of the corrosion worries (though not all).

Curious to see what others would do...

-Sam

bkjeffrey
March 4, 2010, 10:04 AM
Why could you not make the whole can stainless

Cost and ease of matieral procurement. Im actually thinking of using hot dipped galvanized carbon steel from McMaster. The galvanized would resist interior corrosion. I plan on dura coating the exterior so im not worried about that. Its cheap, only problem is its only rated for 150 psi. Theres another item for consideration. How much pressure are we talking about the can being able to contain?

Arkady
March 4, 2010, 08:24 PM
The following list was posted on SilencerTalk by johndoe3 about a year ago:

I ran a simulation on Quickload for muzzle pressures using the maximum SAAMI chamber pressures for each type round, because I was interested. Here is what I found.

308
24" 7656psi
18" 10,794psi
16" 12,388psi
14" 14,445psi

300 WSM
26" 9914psi
24" 10,927psi

22-250
26" 9800psi
24" 10,500psi

223 Rem
24" 7056psi
20" 8725psi
16" 11,254psi
12" 15,462psi

and for kicks 7mm WSM
26" 10,667psi
24" 11,746psi

The above are simulations and are ballpark. Actual muzzle pressures may vary in each caliber by 2-500psi depending on the bullet weight used.

Sorry, didn't see anything about 7.62x39, but it should give you an idea of the numbers you're looking at.

Ranb
March 5, 2010, 04:02 PM
It is rare that I see a silencer for a center fire rifle that can be taken apart for cleaning. I make mind from 4130 steel and just rinse with solvent and oil to reduce the corrosion rate inside. I made an AK silencer from 4130 tubing and bar stock left over from scrap. I turned down .095" tubing to reduce weight, but stopped at .050" because I got tired ot watching the lathe. I could have gone down to .035" I think.
http://i171.photobucket.com/albums/u320/ranb40/firearms/akthreaded-1.jpg
I made a guide to put threads on the muzzle. It did not work well enough, the threads were about .010" off from center.
http://i171.photobucket.com/albums/u320/ranb40/firearms/AKmuzzle2.jpg
So I moved the front sight back. I reamed out the front sight to allow it to slide back and used a file on the barrel to allow the drift pins to go back in. By some miracle the front sight only required a bit of hammering to adjust windage at the range.
http://i171.photobucket.com/albums/u320/ranb40/suppressors/AKsilencer-1.jpg
Very basic design. Sturdy but requires a very straight rifle bore or increased silencer bore to ensure on baffle strikes. I went with a .400" bore.
http://i171.photobucket.com/albums/u320/ranb40/firearms/suppressedwasr.jpg
Ugly can for an ugly rifle. It might work well enough. Works like crap with my reloaded subsonic 220 grain bullets so far.

Ranb

Sam1911
March 5, 2010, 04:21 PM
I like the "snub nose" AK!

giggitygiggity
March 7, 2010, 12:21 AM
What do you have to do in order to legally make sound suppressors? Also, how do you guys make them? I mean, what type of machinery do you use and how do you access it? Thanks.

Sam1911
March 7, 2010, 01:35 AM
What do you have to do in order to legally make sound suppressorsYou should download a "Form 1" from the ATF. That's the form for making a new Title II firearm. (Yes, a can is a firearm -- strange but true.) The ATF's site has all the info you need on the legal steps.

As far as equipment to manufacture one, I can't imagine it would be easy to do without a metal lathe. Probably would want a TIG (maybe a MIG) welder.

You'll need some way to engrave it as well, as your name, location, and a serial number will be required.

Ranb
March 7, 2010, 01:37 AM
If you live in the USA, then you first need to reside in AL, AR, AK, AZ, CO, CT, FL, GA, ID, IN, KS, KY, LA, ME, MD, MO (with C&R), MS, MT, NE, NV, NH, NM, NC, ND, OH, OK, OR, PA, SC, SD, TN, TX, UT, VA, WA, WV, WI or WY to own one without a license. WA bans use. A few others states allow licensed dealers to own them also.

Then you need to obtain the ATF form 1 (application to make and register a firearm), form 5330.20 (certify citizenship), two finger print cards, two passport sized photos of yourself and a check for $200. You can download the forms from here; http://www.atf.gov/forms/download/atf-f-5320-1.pdf (duplicate 2-sided) and http://www.atf.gov/forms/download/atf-f-5330-20.pdf and finger print cards (and other forms) from here; http://www.atf.gov/forms/dcof/ .

You are required to obtain the local sheriff's signature on the back of the ATF form 1 before sending it in to the ATF. If the sheriff will not sign, then you can ask a judge or DA to sign. Most people who have problems obtaining the signature create a trust or corporation to own the silencer for them. All qualified corp officers or trustees can possess the silencer, this is an advantage over over personal ownership.

You then need access to a lathe. It does not have to be a large or good one. I use a cheap chinese hobby lathe that barely holds .001" consistantly. A band saw, drill/bits, and a welder will come in handy also. I ordered one from Grizzly. I use a cheap MIG welder for the high powered rifle silencers. A hand engraver does a good enough job for engraving the silencer. Two of the best forums for silencer hobbists are http://www.subguns.com and http://www.silencertalk.com .

A sielncer will reduce noise by anywhere from 20-30 decibels which is 100 to 1000 times less intensity and 4 to 8 times less loudness. But doe not expect to have anything that is quiet unless the rifle is already not that loud when not suppressed. Some suppressed rifles and pistols will still be too noisy to safely shoot without ear plugs.

Ranb

bkjeffrey
March 7, 2010, 09:22 AM
what do you man it works like crap with 200 gr bullets? minimal noise reduction?

Do you think .4" silencer bore might be letting too much gas by the .3" bullet thereby reducing its effectiveness?

Ranb
March 7, 2010, 11:45 AM
The rounds will not chamber unless inserted into the chamber by hand. They lack the power to cycle the action. Accuracy sucks. This is just preliminary results though. I have heard that 200 grain EBR ammo works well, but there is no way I will ever pay for that expensive stuff.

A large bore is going to let out too much noise. But a quiet gun that can't hit anything due to baffles strikes is just a loud club. And that would suck even more. :)

Ranb

PTK
March 7, 2010, 11:55 AM
No one seems to have mentioned it... please do not use anything zinc in a silencer. Zinc fumes are incredibly bad for you.

bkjeffrey
March 7, 2010, 12:45 PM
reloaded subsonic 220 grain bullets

Just re-read that........gotcha.

bkjeffrey
March 7, 2010, 12:59 PM
so as far as baffles go Im looking at three options:

any one will be in a tube with welded ends so Ill only have one shot at getting it right.

a: monolithic baffle like this

http://i236.photobucket.com/albums/ff117/bkjeffrey/monolithicbaffle.jpg

OR,

b: stacked "k" baffles like these

http://i236.photobucket.com/albums/ff117/bkjeffrey/stackedkbaffles.jpg

OR,

c: a stamped and formed baffle like this MP5SD baffle

http://i236.photobucket.com/albums/ff117/bkjeffrey/mp5sdinternal.jpg

All three would be pretty easy to make. I just wanna get the most effectiveness. This suppressor will be permanatley attached to a draco AK pistol to give a total bbl length of 16.5 inches so Im looking at making the suppressor 7-8 inches long and just shy of 2" in OD.

Thoughts?

bkjeffrey
March 8, 2010, 01:06 PM
No thoughts on any of these baffle designes?...

CoRoMo
March 8, 2010, 01:23 PM
The monolithic is easy to make?

PTK
March 8, 2010, 01:47 PM
None of the three. You should make a stepped cone baffle set for an AK silencer.

bkjeffrey
March 8, 2010, 02:01 PM
The monolithic is easy to make?

Sure, Ive got a mini Bridgeport mill.

You should make a stepped cone baffle set for an AK silencer

Please elaborate.....

PTK
March 8, 2010, 02:07 PM
Buy Al(an) Paulson's books on silencers, check out the smithing section of http://www.silencertalk.com/forum/index.php, etc.

I have no pictures handy, and we both know you know about ST. Monolithic baffle picture... ;)

Riss
March 8, 2010, 03:32 PM
Made 2 of my own design. Both with K baffles. Similar to the AK above for attachment, or like Dr Daters Mk-9 ? suppressor. I would go with a monolith design if I made another. With that type you could easily make a second monolith for another caliber or even adapters for the rear end to accept multiple threading diameters.

Ranb
March 8, 2010, 04:10 PM
With that type you could easily make a second monolith for another caliber.....

While the ATF does not yet require a $200 tax for additional adaptors for attaching a silencer, they certainly do for any additional internals. This is the downside to making a silencer on a form 1 instead of obtaining a license.

My next few builds will be with step baffles. A 5.56 can and one for 22lr.

Ranb

Riss
March 8, 2010, 06:29 PM
The end cap I would make similar to the Coastal Guns MIMS. Well I guess they would have to define additional internals too. Mine was registered under several different calibers similar to why or how some MG's need to be registered will the caliber listed on the form.

Sam1911
March 8, 2010, 06:43 PM
Mine was registered under several different calibers similar to why or how some MG's need to be registered will the caliber listed on the form.

Wow...there's something I never considered! Would there be a significant reason to list anything other than the actual bore of the suppressor? Or the largest caliber intended to be used? (Considering that a .308" suppressor probably is built with a bore of more like .330" or some such?)

Certainly a larger can can be used on a smaller-bore gun with acceptable results, but does the BATFE actually care?

bkjeffrey
March 8, 2010, 07:02 PM
Mine was registered under several different calibers similar to why or how some MG's need to be registered will the caliber listed on the form.

This post doesnt make sense to me at all. Help me out here, my brain may not be working right.

Wow...there's something I never considered! Would there be a significant reason to list anything other than the actual bore of the suppressor? Or the largest caliber intended to be used? (Considering that a .308" suppressor probably is built with a bore of more like .330" or some such?)

Uhhh..............Is there something I am missing here?

I thought as long as the suppressor would thread onto the barrel it could be used on any gun with a caliber of the size of the suppressor or smaller. If a .308 barrel was threaded to 1/2x28 and you had a .30 cal suppressor threaded the same, why couldnt you you use your .30 cal suppressor on a .223 AR with a 1/2x28 threaded barrel?

You guys are losing me here. I just wanna build a good suppressor for my AK, actually for my Draco AK pistol to bring my total barrel length to 16.5+ inches. (yes the suppressor will be permanatley attached).

Sam1911
March 8, 2010, 07:17 PM
On the Form 1 blank 4.c asks for "Caliber, gauge, or size." When registering an AR-15 receiver or T/C Contender receiver as a SBR, for example, you'll probably want to use several different barrels in different calibers or gauges. Used to be you could write in "multi." Now it seems they've decided not to accept anything but the actual numeric designation for a specific caliber -- so many folks are writing in every caliber they might use. (And, every barrel length, as well.)

The question is, a silencer is only a "firearm" because Title II of the NFA SAYS it is, and you can shoot any bullet through it that it smaller than the actual bore size of the can. So, do they really care that you put ".308" on the form if the bore is really .330" and you're going to shoot .308", 7mm, .260, .280, .257, .224, .204, .17, .14, and etc. through it?

bkjeffrey
March 8, 2010, 07:33 PM
So, do they really care that you put ".308" on the form if the bore is really .330" and you're going to shoot .308", 7mm, .260, .280, .257, .224, .204, .17, .14, and etc. through it?

I doubt they care, nor will they ever even know.

Sam1911
March 8, 2010, 07:46 PM
I doubt they care, nor will they ever even know. I tend to agree with you, however the same argument may be made about those SBR rifles. Will they ever know or care that you registered your AR-15 SBR as a 10" barrel in 5.56mm but often shoot it with a 7" .50 Beowulf barrel?

I don't know and I don't know how to find out beyond all doubt. But a lot of folks aren't chancing it these days. [Shrugs ... :confused:]

bkjeffrey
March 8, 2010, 07:53 PM
[Shrugs ... ] ...yea........ shrugs....

Anyway...Im still looking for info on building my AK suppressor.........Wheres RanB? He's hording all the knowlege.

I wanna know what he thinks of the monolithic baffle design.

Ranb
March 8, 2010, 08:05 PM
I do not think any silencer made is the same caliber as stated on the ATF form 1. They are all larger to allow the bullet to pass through without baffle strikes. I think the only way a person would get into any trouble is if they say for example that they are making a 30 caliber silencer, but the bore is less than .300" inches.

bkjeffrey,

I am just a hobbyist silencer builder; I have only made eight cans so far. I rate myself a 4 out of 10 in knowledge and skill as far as silencer making is concerned.

As far as monolithic cores are concerned; I think they are wasteful of volume and weight. While they appear to be very sturdy and durable, I think that they will not suppress as well as conical, step or K baffles. But I have no data to back this feeling up. As I live in WA where silencer use is banned, the opportunities to actually hear how well silencers perform is a rare occurrence for me.

Ranb

bkjeffrey
March 8, 2010, 09:00 PM
Awww jeez RanB, I thought you were the man!:neener: Just kidding.

Thanks for all the help on the Form One. I got it all filled out and am going to take it over to the local Calss III dealer tomorrow for a final review before trying to schedule a meeting with CLEO for final sigs.

Ill post on how that goes when it happens. After that I should have a few months to get all my designs worked out.

Hey RanB, I know you said that your AK suppressor "worked like crap" because it wouldnt cycle your subsonic reloads, but hows it sound with surplus?

Ranb
March 9, 2010, 07:15 PM
I meant that the rifle works like crap with subsonic. I have not used the silencer yet, so I do not know what it sounds like suppressed.

I leave for Vegas tomorrow and am bringing as many guns, silencers and cartridges as I can carry. Alaska Airlines limits a person to 50 pounds of ammo whereas most other airlines have a limit of 11 pounds on domestic flights. I am bringing all of my 7.62x39, 338rum, 30 carbine along with a few hundred rounds of 9mm and 22lr subsonic. About 25 pounds worth. The ticket counter has never put a gun case of mine of the scale, so I loaded it up with 60 pounds of guns/silencers. Worst scenario is that I end up paying the extra $50 for overweight luggage. That is if the TSA does not hassle me about the silencers again.

I will video the results, but I do not expect the video to be high enough quality to show a big difference between suppressed and unsuppressed fire.

Ranb

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