Building a 30-.06 suppressor

Yes, it can be legal to make a silencer. For everything Form-1, from silencer designs that are easily made, to filing forms with the BATF, to 3D modeling. Remember, you must have an approved BATF Form-1 to make a silencer. All NFA laws apply.

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SilencerNewb
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Building a 30-.06 suppressor

Post by SilencerNewb »

I'm looking to build a suppressor for my 30-.06 hunting rifle. Obviously, I'm shooting supersonic, so my real intentions are to reduce muzzle flash and to decrease the report of the rifle (in an effort to hunt without aggressive hearing protection). I have no desire to hunt with sub-sonic ammunition.

My thoughts were to use a 304SS tube, with a 304SS blast baffle and 6061-T6 K-baffles.

For dimensions, it would probably be a 2" OD (the 304 I have on hand is 2" OD with a .125 wall), and maybe 8" long. Using a 1.5" blast chamber, with 5 or 6 k-baffles.

I'm shooting 180gr Core-Lock centerfire rounds.

I'd considered building a high-temp mono-core composite suppressor with a steel sleeve, but I don't have much desire to lay up 100 plies to fill a 1.75" ID with a .30 cal hole in the middle. Plus, the cure for something like that is more than 12 hours in the autoclave, and to reduce bulk I would have to lay it up 2 plies at a time. I'd be laying up for days, and tying up an autoclave for more than a full day. I haven't completely ruled this idea out, however. I'm not sure what I would do for the baffles of a monocore like this, however. Turn in "k-baffles"? Drilling the gas flow holes would be tedious and difficult.

Suggestions?
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Re: Building a 30-.06 suppressor

Post by SilencerNewb »

I was also considering using a rubber disc (with an X-cut) as an exit-wipe. I can cut 100 of them rather quickly, and swap them out if they get worn/torn. I'm working for a very low cycle rate. 1 rd/min tops, and less than 10 rounds at a time. Often, it'll be one or two firings in an outing.

I guess, theoretically, I could use rubber wipes between every baffle. And that would help mitigate baffle growth during heat cycling.

I'm concerned that wipes would drop round velocity or have an impact on accuracy. Has anyone done any testing with/without wipes?

I guess I could cut 8 slits, and have a pilot hole in the middle of the wipe to help prevent problems.

Do most people using suppressors on high-power rifles use a flash suppressor as an adapter for the sound suppressor? Or do you typically thread them directly onto the barrel?
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Re: Building a 30-.06 suppressor

Post by mollinst »

You're an engineer aren't you? :lol:
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SilencerNewb
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Re: Building a 30-.06 suppressor

Post by SilencerNewb »

I just might be...
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Re: Building a 30-.06 suppressor

Post by CThomas »

To the OP do not use wipes as they have no place in a rifle suppressor.
Most here would say that the use of any aluminum in a rifle suppressor is a path to disaster. There are however others that disagree and point to european designs that use and show that aluminum works in low volume hunting rifles.

Go to the link below and read about every Form 1 can made by members here, there is some really good stuff.
viewtopic.php?f=10&t=79895
SilencerNewb
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Re: Building a 30-.06 suppressor

Post by SilencerNewb »

Why not use wipes on a rifle suppressor? Does it significantly impact accuracy? I imagine it would, but I'm making a lot of assumptions about suppressor performance.

I can make all of the baffles out of 304, but I think that'll be pretty heavy.
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Re: Building a 30-.06 suppressor

Post by Bendersquint »

SilencerNewb wrote:Why not use wipes on a rifle suppressor? Does it significantly impact accuracy? I imagine it would, but I'm making a lot of assumptions about suppressor performance.

I can make all of the baffles out of 304, but I think that'll be pretty heavy.
Wipes in rifle cans are ineffective and can cause baffle strikes and accuracy concerns. Not to mention compression if between baffles. Yes we have tested it and ended up with a baffle strike on every baffle and around 50MOA accuracy at 100yds.

You don't want to be using K baffles either, go with cones.

Anything rifle you want to be doing in steel or titanium, aluminum doesn't have a place inside US made cans because you can not replace the baffles if they are damaged(which they will be with Al) only a licensed manufacturer can.
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Re: Building a 30-.06 suppressor

Post by mollinst »

mollinst wrote:You're an engineer aren't you? :lol:

Silencernewb, The reason I said this was not to jab at you but, to say that you seem to be over-thinking in the "feature rich" department and, possibly under-thinking the more basic, but extremely important, mechanical issues like attachment method. OK... I guess that's a jab... But it was meant as a good natured one.

The link CThomas provided is an excellent one, and the search engine is a great tool as well. Read, read, read. And then when you're all done, do some more reading. You'll, most likely, find exactly what you need to.

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Re: Building a 30-.06 suppressor

Post by SilencerNewb »

Oh no, the attachment method is not something I'm really worried about at all. I'm capable of tapping straight threads onto my can end, and cutting threads on a lathe for attaching the rear plug to the can. I'm going to have a gunsmith die treads onto the barrel, mostly because I don't want to take the time to do it myself.

I'm more curious about internal features, and experience that people have with large caliber, high power rifle suppressors. Most of what I've read so far deals with substantially smaller rounds or lower power rifles.

I'll keep reading, that's for sure.

AL baffles, even near-end baffles are subject to significant wear? I didn't realize that it was against Form 1 to make replacement parts for a suppressor. That changes things quite a bit. No matter, I can re-design and buy material to make what I need. Perhaps since I am buying material, I'll use a Ti can with 304 baffles.
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Re: Building a 30-.06 suppressor

Post by mollinst »

"I'm going to have a gunsmith die treads onto the barrel, mostly because I don't want to take the time to do it myself."

Well the barrel should not be threaded with a die, this is a job for the lathe and live center so that the threads will be concentric to the bore as opposed to the OD of the barrel. You may have known this already, and just used the term - die - but, just to be sure. This is one of those seemingly simple, yet extremely critical issues.

If you have reasonable machining skills, there's no reason to farm out any part of the process.
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Re: Building a 30-.06 suppressor

Post by SilencerNewb »

I've got better than average machining skills, but I don't have a lathe where my rifle is stored. I used the term "die" loosely, since I thought it was clear that I understood the need for using a lathe to cut threads.
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Re: Building a 30-.06 suppressor

Post by Bendersquint »

SilencerNewb wrote: I'm more curious about internal features, and experience that people have with large caliber, high power rifle suppressors. Most of what I've read so far deals with substantially smaller rounds or lower power rifles.

AL baffles, even near-end baffles are subject to significant wear? I didn't realize that it was against Form 1 to make replacement parts for a suppressor. That changes things quite a bit. No matter, I can re-design and buy material to make what I need. Perhaps since I am buying material, I'll use a Ti can with 304 baffles.
As Mollinst said, the threads should be single point cut on the lathe not using taps and dies, and if your gunsmith is recommending that for a silencer its time to find a new gunsmith. May be fine for a flash hider but definitely not fine for a silencer.

Most higher powered rounds are cones, and NO ALUMINUM at all inside.

Yes a Form1 allows you to build 1 silencer you can not replace components, parts, internals, mounts etc...

If you have the capabilities and skills to machine Ti then you don't need to be outsourcing ANY of the procedures.
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Bendersquint
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Re: Building a 30-.06 suppressor

Post by Bendersquint »

SilencerNewb wrote:I've got better than average machining skills, but I don't have a lathe where my rifle is stored. I used the term "die" loosely, since I thought it was clear that I understood the need for using a lathe to cut threads.
Based on your terminology and obvious engineering aptitude why would anyone interpret "die threads" as using a lathe and cutting single point threads.
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Re: Building a 30-.06 suppressor

Post by SilencerNewb »

Bendersquint wrote:
SilencerNewb wrote:I've got better than average machining skills, but I don't have a lathe where my rifle is stored. I used the term "die" loosely, since I thought it was clear that I understood the need for using a lathe to cut threads.
Based on your terminology and obvious engineering aptitude why would anyone interpret "die threads" as using a lathe and cutting single point threads.
Because in the sentence prior, I said that I have no problem using a lathe to cut threads.

I'm not really here it quibble over semantics, or have my machining skills challenged. I'm here to learn from those who have built suppressors for high power rifles.

As I also already mentioned, I wont be cutting threads on my barrel, because I don't have access to a lathe where I hunt. I'll have someone experienced cut threads on the barrel, and I will handle building the suppressor.

Since I can't legally build replacement parts, I'll avoid AL in my build. I'll stick to a Ti and/or 304.

What is it that makes AL unsuitable? Is it potential baffle strike damage?
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Re: Building a 30-.06 suppressor

Post by Shift1 »

SilencerNewb wrote:
Bendersquint wrote:
SilencerNewb wrote:I've got better than average machining skills, but I don't have a lathe where my rifle is stored. I used the term "die" loosely, since I thought it was clear that I understood the need for using a lathe to cut threads.
Based on your terminology and obvious engineering aptitude why would anyone interpret "die threads" as using a lathe and cutting single point threads.
Because in the sentence prior, I said that I have no problem using a lathe to cut threads.

I'm not really here it quibble over semantics, or have my machining skills challenged. I'm here to learn from those who have built suppressors for high power rifles.

As I also already mentioned, I wont be cutting threads on my barrel, because I don't have access to a lathe where I hunt. I'll have someone experienced cut threads on the barrel, and I will handle building the suppressor.

Since I can't legally build replacement parts, I'll avoid AL in my build. I'll stick to a Ti and/or 304.

What is it that makes AL unsuitable? Is it potential baffle strike damage?
Kinda getting that feeling on this one....

As I understand it....aluminum does not hold up to well to the pressure and heat cycles to well. Kinda like working a piece of sheet metal back an forth until it finally lets go.

Lots of good reading in the pages...lots of .308 stuff (similar pressure cycle to '06). I see from you initial post, you are wanting to use K baffles. I would suggest that you follow the tried and true advice.....Look at what the manufactures do and follow their lead.
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Re: Building a 30-.06 suppressor

Post by SilencerNewb »

Seems logical. My ROF is going to be very low, but that isn't any excuse to balk typical convention. My suppressor should be able to perform regardless of ROF and not being allowed to replace my own baffles makes AL an expensive option.

I'll have to root around my scrap piles and see what material I can come up with.

At the moment, I'm planning to stick with 304. It's cheap and easy to work with. If I'm successful, then I'll submit another Form-1 and build a Ti copy.

I'm still pretty intrigued about building a carbon fiber monocore. Has anyone ever built a successful monocore suppressor for a high power rifle? Has anyone ever built a composite monocore?

What are the laws regarding the sale of a Form-1 suppressor?
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Re: Building a 30-.06 suppressor

Post by Bendersquint »

SilencerNewb wrote:Seems logical. My ROF is going to be very low, but that isn't any excuse to balk typical convention. My suppressor should be able to perform regardless of ROF and not being allowed to replace my own baffles makes AL an expensive option.

I'll have to root around my scrap piles and see what material I can come up with.

At the moment, I'm planning to stick with 304. It's cheap and easy to work with. If I'm successful, then I'll submit another Form-1 and build a Ti copy.

I'm still pretty intrigued about building a carbon fiber monocore. Has anyone ever built a successful monocore suppressor for a high power rifle? Has anyone ever built a composite monocore?

What are the laws regarding the sale of a Form-1 suppressor?
You can sell it so long as it wasn't built to be sold, only manufacturers can sell creations with the intent for it to be sold.

Good luck finding someone to buy a Form1 silencer unless yours smokes the market in performance. Hard enough selling a used commercial can let alone a home made can.

Yes successful carbon fiber and composite have been built but not for the commercial market.
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Re: Building a 30-.06 suppressor

Post by featherhead »

SilencerNewb wrote: I didn't realize that it was against Form 1 to make replacement parts for a suppressor.
I'm ready to throw my hat in on building a silencer and have read the GCA regs. I believe any individual can apply to make and register a silencer. They can then recruit a FFL gunsmith to help them with the build. Any and all parts can be replaced if they retain the same configuration as the original.

http://www.atf.gov/firearms/faq/nationa ... ncers.html

Q: May a Federal Firearms Licensee repair a silencer by replacing worn or damaged components?

A person who is licensed under the Gun Control Act (GCA) to manufacture firearms and who has paid the special (occupational) tax to manufacture National Firearms Act (NFA) firearms may replace a component part or parts of a silencer. Repairs may not be done if they result in removal, obliteration, or alteration of the serial number, as this would violate 18 U.S.C. § 922(k). If a silencer part bearing the serial number, other than the outer tube, must be replaced, the new part must be marked with the same serial number as the replacement part.

The term “repair” does not include replacement of the outer tube of the silencer. The outer tube is the largest single part of the silencer, the main structural component of the silencer, and is the part to which all other component parts are attached. The replacement of the outer tube is so significant an event that it amounts to the “making” of a new silencer. As such, the new silencer must be marked, registered and transferred in accordance with the NFA and GCA.

In the event that identical replacement parts for a silencer are not available, new and different component parts may be used as long as the silencer retains the same dimensions and caliber. In addition, the repair may result in a minimal reduction in the length of the outer tube due to rethreading, but repair may not increase the length of the outer tube. Increasing the length of the outer tube significantly affects the performance of the silencer and results in the “making” of a new silencer. As stated above, a new silencer must be marked, registered and transferred in accordance with the NFA and GCA. Reducing the length of the tube by a minimal amount in order to repair a silencer is often necessary to replace damaged end caps, as the tube must be rethreaded. Such minimal reduction of the length of the tube uses all of the original parts, does not significantly affect performance of the silencer, and may be done as part of a repair process without making a new silencer.

Persons other than qualified manufacturers may repair silencers, but replacement parts are “silencers” as defined in 18 U.S.C. § 921(a)(24) that must be registered and transferred in accordance with the NFA and GCA.

Q: May the outer tube of a registered silencer be repaired due to damage? If so, may the repair be done by someone other than the original manufacturer?

A damaged outer tube may be repaired by any Federal firearms licensee qualified to perform gunsmithing or by the registered owner. The repair may not alter the dimensions or caliber of the silencer, except that the length of the outer tube may be reduced, as set forth above. The repair may not be performed if it results in the removal, obliteration, or alteration of the serial number, as this would violate 18 U.S.C. § 922(k). In that case, the silencer may be returned to the registered owner in its original, damaged condition or destroyed. A replacement silencer must be registered and transferred to the registrant of the damaged silencer in the same manner as a new silencer, subject to the registration and transfer procedures of the NFA and GCA.
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Re: Building a 30-.06 suppressor

Post by Bendersquint »

featherhead wrote:
SilencerNewb wrote: I didn't realize that it was against Form 1 to make replacement parts for a suppressor.
I'm ready to throw my hat in on building a silencer and have read the GCA regs. I believe any individual can apply to make and register a silencer. They can then recruit a FFL gunsmith to help them with the build. Any and all parts can be replaced if they retain the same configuration as the original.
ANYONE can help you build the silencer so long as you are present and if you leave no parts are left behind.

If an FFL helps and you are not present they must be an SOT manufacturer as well.

Any and all parts can be replaced by an FFL/SOT manufacturer, except the registered component. Individuals can not replace any parts except wipes even when they make it themselves.
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Re: Building a 30-.06 suppressor

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Shift1 wrote:As I understand it....aluminum does not hold up to well to the pressure and heat cycles to well. Kinda like working a piece of sheet metal back an forth until it finally lets go.
No kidding . . .

It certainly won't hold if its 6061, even 7075 won't hang in there if you use it often.

The first monocore I made for a stubby 300blk can deformed and blew out of the end of the gun and launched the endcap down range.

.080" thick blast baffle in 6061 but it was a ~1.875 diameter core.

The next one was 7075 and .100" thick and it still deformed some.

I can only imagine what supersonic .308 would do OR how thick you have to make the baffles to get it to last.
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delta9mda
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Re: Building a 30-.06 suppressor

Post by delta9mda »

here we go again.
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mx201er
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Re: Building a 30-.06 suppressor

Post by mx201er »

I made a 22lr monocore can out of aluminum; after several hundred rounds, even it is showing a good amount of wear on the bore hole of the first few baffles from the hot gas out of the barrel. I can not imagine it holding up very long on a centerfire rifle..
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Re: Building a 30-.06 suppressor

Post by Shift1 »

delta9mda wrote:here we go again.
Yup.....I hear ya..
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Re: Building a 30-.06 suppressor

Post by SilencerNewb »

Sorry about the delay, I had to deal with a car accident.

Right now, I'm planning on submitting a Form1 and building a cone-type 304SS suppressor. I'm going to draft out some ideas for rough specs before I submit.

If it works, I'll submit another F1 and build a copy in Ti to shave weight.

Right now, I'm going to use threaded caps on both ends. It'll be easier to build, and easier to clean. I'm going to use wave-washers between the spacers to keep the stack in tension, and keep some preload on the caps to help keep them from loosening. I'm also planning on cutting o-ring grooves on either end, to further help keep the caps in place. I'll anti-sieze the threads, and probably disassemble/clean with every gun cleaning (every 10 rounds or so).

Questions:

1) I've seen all different opinions on blast chamber length. Some say 1", some say 2", and everything in between. Opinions?

2) Has anyone run perf pipe down the center of a suppressor?

3) Clearance to bore? I was thinking of sticking with +0.050" on the diameter from general reading on here. Will I notice a substantial difference in sound if I tighten that to, say, +0.025"?

Anything else I should consider in design?
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Re: Building a 30-.06 suppressor

Post by Bendersquint »

SilencerNewb wrote:Sorry about the delay, I had to deal with a car accident.

Right now, I'm planning on submitting a Form1 and building a cone-type 304SS suppressor. I'm going to draft out some ideas for rough specs before I submit.

If it works, I'll submit another F1 and build a copy in Ti to shave weight.

Right now, I'm going to use threaded caps on both ends. It'll be easier to build, and easier to clean. I'm going to use wave-washers between the spacers to keep the stack in tension, and keep some preload on the caps to help keep them from loosening. I'm also planning on cutting o-ring grooves on either end, to further help keep the caps in place. I'll anti-sieze the threads, and probably disassemble/clean with every gun cleaning (every 10 rounds or so).

Questions:

1) I've seen all different opinions on blast chamber length. Some say 1", some say 2", and everything in between. Opinions?

2) Has anyone run perf pipe down the center of a suppressor?

3) Clearance to bore? I was thinking of sticking with +0.050" on the diameter from general reading on here. Will I notice a substantial difference in sound if I tighten that to, say, +0.025"?

Anything else I should consider in design?
1 - All depends on the diameter of the can and mounting method.
2 - Yes and it does nothing but add weight.
3 - Yes, you will notice a difference the tighter you go but remember you can't replace components so you have to build some room for error into it, most Form1's I see from strikes are from tighter than .05" over bullet diameter. Most Form1 builder play it safe with .05-.07 clearance.
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