How to Build a Silencer for .308 Rifle

Andrew Garfield
By Andrew Garfield January 10, 2019 07:47

How to Build a Silencer for .308 Rifle

This article was gladly contributed by author Andrew Garfield.

.308 rifle is a most popular rifle across the shooters or hunter’s world. When it is about long-range shooting or hunting then .308 rifle is the top choice to the hunters or shooters.

If you own or planning to buy a .308 bolt action rifle, you probably thinking to have a silencer. Not necessary to buy, you can make it at your home and we are going to tell you how you can do it.

When you talk about how to build a silencer for .308 rifle at home, some people mistake you for a dangerous and unlawful person.

But that isn’t necessarily true.

All naysayers aside, homemade silencers are perfectly legal, as long as you meet certain criteria of law.

States and countries have different criteria. So, it’s important you know what your particular jurisdiction says about making rifle suppressors at home else you end up in trouble. Some jurisdictions require you to fill out form 1 and pay a tax stamp for each silencer.

How you make a silencer depends in no small part on a baffle design.

There are two ways you can make baffles.

One way is to buy a round metal bar as a main tube and drill it to create baffles and bullet paths. Another way is to create individual baffle cones, which you can stack them up in a main tube.

All angles and axes must have perfect alignment. You’ll require a mill or a lathe to cut out materials precisely.

There are things you need to consider, because they affect material to use, volume, size of drill bits, number of baffles, and barrel length for a silencer.

What Material You Need for the Main Tube or Can

Whether you want create stacks of baffles or drill baffles and a bullet path in a round metal bar, either way you’ll require a round metal tube to cover the baffles and spacers. Make sure the material makeup is any of the following:

  • Stainless steel
  • Aluminum
  • Chrome molybdenum steel
  • Titanium

How to Build a Silencer for .308 RifleWe highly recommend chrome molybdenum steel, owing to its durability, hardness and toughness.

In addition, paints and polymers won’t peel off from the material surface, adding to toughness and corrosion resistance. You can machine the material easily.

Ensure the external diameter of the round bar is 1.5-inches. A baffle cover round tube must have an internal diameter of 1.5-inches (3.8cm), wall thickness of 0.125-inches (0.31cm) and external diameter 1.75-inches (4.4cm). Length should be between 8-inches and 12-inches.

Related: What To Do When Gun Control Gets Really Bad

Tools

  • A plugin or a rechargeable drill or a drill press
  • A vice, a hacksaw or a chop saw
  • Drill bits
  • Steel wool or sand paper
  • Cutting oil
  • Hydraulic shop press (if you decide to create baffle stacks)
  • Files, grinders or belt sanders to even out spacers and clip baffles

Blast Baffle

Make sure the surfaces and bores of baffles have a perfect symmetry and alignment to each other to prevent the blasting bottle-shaped gas from overtaking and deflecting the bullet.

You also don’t want bullets to make contact with baffles, nor do you want them to tumble and keyhole. Use stainless steel or Inconel to make the blast baffle.

Related: How And Where To Store Ammo

What Length of Silencer You Need for Your Best 308 Bolt Action Rifle

Optimum lengths for a silencer should be between 8-inches (20cm) and 12-inches (30cm) in front of the barrel bore.

If you’ve a sniper rifle, we’re talking about a barrel length ranging between 24-inches (60cm) and 30-inches (75cm). Adding a muzzle blast silencer elongates your rifle.

To accommodate the silencer, you must cut the barrel length, but you’ll lose speed and obtain more accuracy. We recommend you cut your barrel length down to between 16-inches (40cm) and 18-inches (45cm).

Step-by-Step Process of Building a .308 Silencer

From a Round Metal Bar

How to Build a Silencer for .308 Rifle

  • Use a tape measure to determine the most suitable length of your suppressor. Cut the round metal bar at that length using either a hacksaw, a chop saw or a vice.
  • On the mill, face both sides of the metal bar and the cover tube to ensure they fit and align precisely when you screw your silencer onto the muzzle. You shouldn’t experience problems when mounting the bar and the tube in the mill.How to Build a Silencer for .308 Rifle
  • Create threads by which you’ll screw the barrel by drilling a tap hole on one side of the bar.
  • Make sure the depth of the hole is sufficient for a silencer to screw onto the all the threads present on the barrel.
  • For a .308-inch tap, the diameter of the hole should be 5/8-inches and threading should be 24 threads per inch (tpi). You’ll require a drill bit whose size is 9/16-inch to create the hole of that size and depth.How to Build a Silencer for .308 Rifle
  • While drilling, ensure the drill bit is steady, and aligns perfectly with the tail stock when the mill rotates the metal bar. When you want to align the tap with a bullet path, avoiding using the mill power.
  • Instead, use a tailstock to hold the tap in place. Tighten the tailstock by pushing it into the metal bar.
  • Use your hand to turn the chuck of the mill to begin the tap, so you can sense the bottoming out of the tap. Use a standard wrench for tap hand to complete tapping.

How to Build a Silencer for .308 Rifle

  • Through the metal bar, drill a bullet path using a smaller bit than the hole of the thread. The bit size should be 11.32-inches to match a .308-inch bullet.
  • You don’t need a long bit as you can drill from both sides in turn. Using the tailstock, hold the bullet steady as the mill rotates the metal bar.
  • Create baffles by milling out or drilling the gas chambers. Before you do that, mark spots to mill out with shapes of your choice (suitably odd) on the metal bar.
  • Drill the spots using any bit before you use mill power for finishing. Maximize the volume of the gas chambers by milling out as much metal as you can to ensure there’s less metal between them. This will also shed off extra weight.

You require fewer baffles and more volume for a supersonic than a subsonic bullet.

  • Don’t forget to leave sufficient metal on the side which the silencer would screw onto the barrel. As in, the silencer end and the blast baffle shouldn’t be too near.
  • Remove metal debris from the bullet path using a drill bit.
  • On the mill, face both sides of the cover tube.
  • Polish the cover tube using steel wool or sand paper.
  • Slide the milled metal bar into a cover tube. Weld both sides of the tube to cover the silencer. Ensure length of the cover tube and the metal bar match.
  • You’re now ready to screw the can onto the barrel of your rifle.

People can easily mistake for a dangerous criminal when you bring up a conversation about how to build a silencer for .308 rifle at home.

There are a lot of legal restrictions, so before you decide to make a suppressor, you must consult the law. You don’t want to end up in trouble with authorities.

Next thing, know your choice of baffle design, whether you want to create individual stacks of baffles or you want to mill out baffles and a bullet path in a round metal bar. We’ve discussed the latter choice, because it’s relatively straightforward.

You may also like:

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Andrew Garfield
By Andrew Garfield January 10, 2019 07:47
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41 Comments

  1. SoCal prepper January 10, 16:36

    Bad article! Technically and legally.

    Reply to this comment
    • 1 old _art January 10, 17:31

      SoCal prepper
      How can you say this article is bad legally, it clearly states to check the laws governing suppressors in your
      area. The laws vary greatly by location.

      Reply to this comment
      • left coast chuck January 25, 18:56

        Unfortunately, federal laws apply in all 50 states, no matter what some folks feel about them. I’m not a lawyer, but almost everybody who is active in the firearms field knows that possession of a suppressor, home grown or store bought without a permission slip from our masters in the District of Corruption will result in your incarceration as deep in a federal penal institution as if you had murdered someone.

        Unless you are already a felon, in which case you will merely have the suppressor confiscated and continued on probation or parole and warned to go and sin no more.

        Reply to this comment
        • joe February 6, 04:05

          i know suppressors can be bought in gun shops in the St Louis, MO area

          Reply to this comment
          • 54E February 12, 05:11

            Yep, you can buy ’em but you can’t walk out with them until you fill out the ATF paperwork, get the paperwork signed by the chief LEA official in the area you and the suppressor will live in and send iot in with $200 to ATF. They will do things with the paperwork for from 9 to 12 months (hope there’s no problem with the paperwork or you can be starting at square one again) and, if you’re approved, receive a tax stamp and the appropriate certificate.

            Don’t forget to send in the form listing the places where you intend to take the suppressor, especially if you want to take it out of state. If you’re going to take it outside of the jurisdiction it was approved for make sure where you’re taking it has no objections. Also, when you are out and about with your can it’s best to take copies of the ATF form and any related state paperwork unless you want to see it impounded until you can prove it’s legally yours.
            I have suppressors and it’s a problem to travel with them. They’re fun to play with but can be a serious drag.

            Reply to this comment
  2. Rusty118 January 10, 16:43

    This is about as clear as mud.

    Reply to this comment
  3. left coast chuck January 10, 17:03

    Just cut the barrel to between 16 and 18 inches. No mention of assuring that the cut is square. No mention of crowning the muzzle. What about threading the end of the barrel so that the silencer can be screwed onto the barrel? If one has the capability to perform all the milling and metal work involved in the construction, surely that journeyman machinist can certainly thread the end of the barrel. That is probably the easiest portion of the whole exercise.

    Reply to this comment
  4. Tom January 10, 18:44

    Pretty technical for the average Joe.

    Reply to this comment
  5. Mike January 10, 19:25

    This is a little short on specifications but enough I think to make one for my 22 air rifle.

    Reply to this comment
    • left coast chuck January 10, 23:55

      Mike: You can buy a sound suppressor for your .22 air rifle from Pyramid Air Guns. It probably would cost no more than buying the supplies to make this silencer. Not only that, but you don’t have to register a suppressor for an air rifle with the federales and don’t have to pay $200 for permission to do so.

      While I am not up on all the details of owning a suppressor as they are totally, absolutely verboten here in the PDRK and make PDRK politicians froth at the mouth and fall on the floor, I think you still have to get permission from your masters in the District of Corruption and pay the obligatory $199.99 for permission to have the suppressor he is describing in the article.

      Reply to this comment
      • Mike January 11, 02:53

        Thanks for that info. I do have a lathe, milldrill and some stock on hand so I don’t consider it too big a deal to do in my retirement. Do have another tripod mounted 22 motorized for elevation and equatorial movement with a scope. Want to mount a camera on the scope so’s I can sit back in leisure and watch the squirrels get popped on a telly! Retired and evil!

        Reply to this comment
      • left coast chuck January 25, 19:26

        Upon reading Mike’s post with its reference to an article from Pyramid Air, I realize that my post is full of misinformation. I can’t delete it, but I can post this disclaimer and I hereby do so. The only part that is still correct is the second paragraph. The first paragraph is erroneous and should be disregarded.

        Sorry about the grossly wrong information. I try to avoid such mistakes, but, unfortunately, like most everybody else, sometimes when I try walking on water I sink to the bottom. This was on such occasion.

        Reply to this comment
  6. PB dave January 10, 19:42

    Seems to be a whole lot of holes in this article….. Needs some clarification on silence and suppression…. also on muzzle blast vs. bullet crack,….. If you slow the bullet speed will you need to modify that AR base to function at lower pressures ? …. Lots of variables not addressed. Not to mention ATF process to buy/build/ or own a suppressor.
    Building one is possible just don’t get hurt or in trouble doing it. Do your homework.

    Reply to this comment
  7. Josey Wales January 10, 20:51

    Please, please, please! There are many flaws in this DIY silencer, suppressor article! I am shocked this was even allowed to be printed! A .308 is not the most powerful long range rifle available. Do Not cut off the barrel! If you do succeed in building this ‘silencer’, it may destroy your firearm and severely injure you and others! All of that time and work spent and when you pull the trigger it will still go BANG! Silencing starts with a bullet that travels at sub sonic speed, meaning it doesn’t break the sound barrier of 760? miles per hour. I’m begging you folks to please be very careful with the information in this article.

    Reply to this comment
  8. Josey Wales January 10, 21:02

    Left Coast Chuck is correct! The crown on the muzzle needs to be perfect! It will not be accurate and send bullets nowhere near the bullseye in any consistent manner. When you shorten a barrel you loose velocity which is measured as feet per second that the bullet travels. You have a slower moving bullet that that does not hit as hard. (ft. lbs. of energy) My general rule in hunting is (Speed Kills.)

    Reply to this comment
    • Old jughead May 10, 15:53

      Once again Josey has it right. Doubling velocity quadruples energy while doubling bullet weight only doubles energy. However heavier bullets are effected less by wind and rotational drift at longer ranges beyond 500 yards and will still deliver enough energy to be lethal on large game if you use a bullet with good weight retention 93% or greater. Also shorter stiffer barrels achieve higher accuracy and tighter grouping as long as it is 20 inches to 24 inches. Most factory load .308 win is designed to achieve full propellant burn at 20 inches, anything shorter reduces velocity significantly.

      Reply to this comment
  9. Knowledgeable January 10, 21:18

    This is one of the worst written Internet articles I have ever read.
    First and foremost let’s not forget that there really is no such thing as a silencer. Maybe in Hollywood movies, but certainly not in real life.
    Call it a suppressor. SUPPRESSOR.
    Even if were totally legal to build your own suppressor no one attempting to follow these instructions could complete the build.
    I guess that’s your failsafe argument should you be targeted for prosecution for recommending an illegal act. But you SHOULD be prosecuted for bad grammar, sentence structure, logic, and more.
    These few examples tell the story. They mean nothing, mislead, and confuse the reader:
    “Use a standard wrench for tap hand to complete tapping.”
    “To accommodate the silencer, you must cut the barrel length, but you’ll lose speed and obtain more accuracy.”
    “Using the tailstock, hold the bullet steady as the mill rotates the metal bar.”
    If you are going to describe how to build something why not start with a description of the item itself, what it’s parts are, and how they work together.
    Your article totally lacks any sense, and explains nothing except your ignorance and lack of enough brain power to attempt writing.
    I recommend returning to your Lego sets.

    Reply to this comment
  10. TSgt B January 10, 22:31

    This has to be one of the most poorly written articles on this topic that I have ever attempted to read. Many of the statements make very little sense, especially to those with little technical knowledge or practical experience. Were I the authors, I would withdraw this post, seek some assistance both in the legal and technical areas, and give strong consideration before publishing such an atrocity again.

    I have some experience in construction of suppressors, and this article borders on dangerous.

    Reply to this comment
    • Trackermike January 12, 07:07

      I agree with the article being dangerous and totally misleading in every respect! First the teenager on YOUTUBE shows in his video how he built his, and made more sense than any part of this article. If you think you have to make a suppressor, start by getting correct information and start with lower pressure levels like a .22lr, mistakes might be survivable. But with any caliber the BATF will not be very understanding, and you could still do time and be fined thousands of dollars. Be safe and think about it.

      Reply to this comment
  11. Labienus January 10, 23:54

    Yeah for all that money, time, time spent on a learning curve and equipment, I’d rather just buy one meant for my rifle instead of risking damaging my gun or getting hurt.

    Reply to this comment
  12. left coast chuck January 11, 00:03

    This article is a good companion piece to go with the associated article “Top 6 Popular Types of Guns Not Suitable for SHTF” which was full of misinformation. Apparently written while the author was under the influence of some perception altering substance. He was significantly raked over the coals for his egregious errors in the piece with well over 100 posts pointing out his errors.

    Reply to this comment
  13. Garth January 11, 01:48

    I wouldn’t trust this moron to install batteries in a flashlight. You’ve got to be kidding me……

    Reply to this comment
  14. Hoosier Homesteader January 11, 12:50

    NO WAY, would I try this. Nope, nope, nope!
    Too much missing info.

    Reply to this comment
  15. Rando January 12, 11:38

    What sort of a F wit are you sport? I agree with every post advising others about how bloody stupid you are.
    You obviously don’t have a clue about Ballistics. You Idiot. Anyone who follows your advice and your instructions, will be committing suicide, and you MURDER. I’m an Aussie, with 34 years service in the armed forces, A gunsmith, and have made silencers in the past..•22 only. 60 years hunting and Shooting experience. This article is total Bullshit. You are a total Dick head.

    Reply to this comment
    • left coast chuck January 13, 02:42

      Once again, we have a poster with a limited vocabulary. While all of us who posted deplored the insufficiency of the article and some insisted that the article was dangerous, none used vulgarity or personally insulted the author. We all have the right to disagree with the validity of the article, especially when it involves an issue of safety, but being personally insulting is really not called for. I think the author got the point that his article needs significant rework. We can’t all be Winston Churchill with his towering command of the English language. Wow! How I like to read him and feel the words just roll off the page. Nor are any of us William F. Buckley Jr. with his command of English and writing ability. He is another joy to read. If you enjoy reading compelling English which I feel is the richest language in the world due to its many language contributors, I highly recommend both of those authors. And, I might add, they could insult someone mightily without a single vulgarity.

      Reply to this comment
  16. Yosemite January 13, 05:19

    I have learned far more on Youtube.

    The .308/7.62 NATO is NOT the most powerful caliber out there.

    Military Snipers use a various of calibers and rifles…….varying on Mission or whatever, the 5.56, .300 Winchester Magnum, the .300 Lapua, the .50 Barrett BMG. perhaps others that reach out longer ranges (Shoot Flatter) and hit harder than the .308/7.62 NATO

    The 6.5 Creedmore is coming to be recognized and it shoots flatter and hits harder than the .308 Winchester/ 7.62 at longer ranges….It MIGHT or MIGHT NOT be in services at this time. Go look at the ballistics on it.
    It eats the .308 Winchester / 7.62 NATO for Breakfast, Lunch, and Supper!

    Suppressors are like anything else…..you get what you pay for…..There are TWO Questions…..

    1.How much money do you have?

    2.How quiet do you want to go?

    Reply to this comment
  17. Mike January 13, 14:55

    Just priced out silencers for my .22 Benjamin air rifle. Good grief Charlie Brown! We are talking in the $200.00 range! Cheaper for me to make my own but then after reading about the legalities of silencers I may just forget the entire idea and stay with the supplied shroud.

    Reply to this comment
    • left coast chuck January 25, 19:02

      Mike: I’m not a lawyer, but from everything I have read, you don’t need a permission slip form your masters in Washington to have a suppressor on your air rifle. That was somehow overlooked by our all-knowing DC masters.

      Reply to this comment
      • Old jughead May 10, 16:16

        It was “overlooked “ because air rifles are not FIREARMS so laws governing FIREARMS do not apply. There is no background check to purchase an air rifle either for the same reason.

        Reply to this comment
  18. Sassie January 13, 19:06

    You can carry a hand full of rubber balloons with you to a hunt Slip a balloon over the end of the barrel. It will suppress the first shot and a little of the second round. Condoms will work too but you’ll need a rubber band to hold them on the barrel.

    Reply to this comment
  19. Yosemite January 13, 19:41

    Mike
    Air rifles ARE NOT firearms. There are no BATFE laws regarding Suppressors on Air Rifles……I have seen numerous air rifles over the years that come with factory suppressors on them.

    As for the size of the can to use you might find something on Youtube.

    OR

    You can do a search on suppressors/ How to make suppressors for air rifles.

    IF I can make a suggestion IF you are going to make your own I would highly suggest that you look at all of the various baffles Especially in the HIGH END/COST range and compare all of the various designs……The higher end cost ones are more effective than the low end ones…..learn from their designs..and modify to your needs..that is IF you can make your on baffles.

    Good Luck and I wish the best of success.

    Reply to this comment
    • Mike January 13, 22:06

      I thought the same about silencers on air rifles until I read this article from Pyramid Air, https://www.pyramydair.com/article/Airgun_silencers_What_s_the_big_deal_August_2006/32

      Reply to this comment
      • Yosemite January 14, 01:25

        It is okay IF….
        1.The Suppressor cannot be removed from the barrel and be used or adapted as a suppressor on a real firearm.

        2.Next IF the suppressor is NOT made of materials that would be able to be used on a firearm or would be destroyed if used on a real firearm…THOSE are your work arounds…….

        From what I understand our needs/wants to be…..you won’t be moving carrying the rifle much so the tube will not be battered or stressed about…..

        Just for S,G, and G ….for example sake the tube was made of paper towel or other light cardboard tube but NOT the heavy cardboard tubes just light cardboard tube and IF that does not work try lightly wrapping it in tape.

        For Baffles perhaps or Paraffin or wax baffles………..I mean if you want to try something like that I don’t see how they could say such materials would stand up to a real rifle since the heat would melt the paraffin or wax and pressure also would destroy the tube….

        You can buy blocks of paraffin in most grocery stores cheap enough…. l

        I am only using this for example to try One thing for sure it will not hurt your weapon!
        Who knows? it might be crazy enough to work…..paint it black and unless someone looks close….

        NOW that should keep the BATFE happy…I am sure the cardboard tube would disintegrate if tried on a rifle or handgun…..I would highly suggest one test it out and make sure……(You might want to use a leather or neoprene wipe between the muzzle and the Tube… but try it without first and see what happens o the tube…

        I am quite sure centerfire rifles and handguns would destroy the tube with their muzzle blast…. .
        Check it on a .22 rifle if it does not shred or it actually works as a Suppressor.. destroy it and back to the drawing board!

        NOW IF I could just make money off of that idea would be VERY HAPPY!!!!

        BE SURE to Check your State and Community laws…

        FYI, I have seen ways to mount your cell phone to your rifle scope….
        You can find the mounts on Amazon and elsewhere

        Reply to this comment
      • left coast chuck January 25, 19:22

        Mike: Thanks for posting that link. It made interesting reading. It certainly opened my eyes to things that had escaped me. I knew, for instance, that owning a suppressor without a permission slip was right up there with assassinating a federal official as far as how seriously the federales took it — unless you were already a felon, in which case it isn’t all that serious. IF you are a first time loser though, you can expect to be thoroughly reamed by the legal system.

        The author of the link is Mr. AIRGUN. He is a recognized authority on airguns and I personally give his opinions significant weight when it comes to airguns and airgun accessories. If he recommends no home grown suppressors on airguns, I would follow that advice to the letter.

        Airguns really aren’t that noisy anyway until you get up into the bigger calibers like .375 or .45 or .50 caliber. I have a good old fashioned Benjamin .22 and it makes less noise than my Daisy .177 break action or my — I don’t remember who made it — .177 CO S&W Model 29 look alike.

        Reply to this comment
  20. Yosemite January 13, 20:04

    OH YEAH …If you need a tube look no further than multi-cell Maglight C or D cells.

    The heavy duty thick walled CVC pipe will also work for air rifles and probably the .22 LR……

    There are Suppressors that will Twist Lock On and Off around the front site on some weapons. I would suggest using neoprene lined inside the suppressor to keep from marring the finish and a better seal… you can find it on the cheap drink coozies used to hold canned drinks and often free because the are adverting something

    .There is no need to chop the barrel and F it up. A crock of crap and a serious case of Stupid in Action!

    Most AR platforms are threaded and have a Flash suppressor. Remove the Flash suppressor and screw on the new suppressor.

    The Ruger Gunsite Scout Rifle has a Flash Suppressor that can be removed and replaced with a Sound Suppressor.

    There are numerous handguns already threaded and ready for a Suppressor such as the Ruger .22./.45 Numerous other manufactures make them threaded for a suppressor as well.

    Reply to this comment
  21. TheSouthernNationalist January 13, 20:10

    Dont do this to your rifle or any other weapon you own, period!

    Reply to this comment
  22. Dean4 January 31, 21:36

    check out infiniteproductsolutions.com for quality thread adapters for anything – Eg – mag lite precision CNC done to help your build – much more

    Reply to this comment
  23. 357MAX February 23, 01:33

    I was told the feds can come in your house anytime if you pay the tax and build a siencer. And they don’t need a warrant. Is this true. the best thing to use is a oil filter?

    Reply to this comment
  24. WartHog 91' February 26, 13:01

    Seems to me the aluminum threaded tube could not with stand the 308 pressure and blow the threads apart. You must use a titanium or SS tube and caps.

    Reply to this comment
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