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Is it legal to modify your suppressors?

Discussion in 'NFA Firearms and Accessories' started by Montanan09, Mar 24, 2013.

  1. Montanan09

    Montanan09 Member

    Does anyone have some first hand knowledge about what the registered owner of a suppressor can potentially do to alter the suppressor? I am specifically interested in options for adding additional suppressor volume to some of the units I have that do not take full advantage of the space made available by elevated sights, etc. In other words, are we allowed to add additional "suppressor-like" features to an existing, registered suppressor?

    Here is an example that I think will get some of you other suppressor owners interested: One of my units is a .45 pistol suppressor that I also use on an HK UMP conversion. If allowable, I could easily double the amount of volume of the existing can without interfering with the sights. And, this can has a LID that I use with pistols so obviously it is allowable to change the length of the suppressor when the LID is attached.

    The potential is there for many rifles too. The 5.56 can I have for my AR's could basically fit inside of another larger can for greater sound suppression when used on my MSAR. The question is, are we allowed to do this? Or, are any savvy suppressor manufacturers working on this type of configurable/modular strategy already?
  2. kimbershot

    kimbershot Well-Known Member

    sounds like you have "parts" for another suppressor--don't think this will fly.
  3. joeschmoe

    joeschmoe Well-Known Member

    Making your suppressor longer than listed on your application could be a problem too. This is all nit picking, but the ATF has put people away for less. Until you read an ATF letter that says it's okay, it's probably best not to change the design or have extra parts. Modifications could be considered "manufacture" which can only be done by an FFL (07?).
    Generally there is no experimentation allowed with suppressors by the end user, even home made ones. Repairs and mods must be done by a licensed manufacturer.
    Ask over at silencertalk.com for a more definitive answer.
  4. MaterDei

    MaterDei Well-Known Member

    If you have an oil filter suppressor then every filter you have is an extra part and often of a variety of sizes.
  5. Montanan09

    Montanan09 Member

    Good points in these responses. Kind of odd that the oil filter adaptor can be registered as a suppressor despite having the ability to attach to a wide range of filter sizes, yet apparently other suppressors cannot have their dimensions modified. I'm not at all interested in making any changes to my suppressors, but I do think there is some viability to manufacturers making modular add-ons for existing suppressors that would allow greater range of use and flexibility. Perhaps they are now looking into that since the oil filter units are most likely cutting into their margins!
  6. I would guess that if you stay inside the tube, with no exterior changes, you could easily get a letter of approval.
  7. Flyincedar

    Flyincedar Well-Known Member

    Haven't seen any cut in sales at all due to oil filters. They can't replace a quality can. There may be some looking into a modular system, but I can't see it as a viable production item. An already quality suppressor comes with a hefty price tag at times, and adding un needed options would just drive the price higher. Sure, some would buy it, but not likely enough to justify making them.

    I've seen lots of comments about what a can really costs to make, etc. Problem is, the people saying they are so cheap to make and shouldn't cost so much only factor in material costs, and not billable machine time, overhead including employees, R&D, etc
  8. pikid89

    pikid89 Well-Known Member

    I may be wrong, but if im not mistaken, the oil filters are considered disposable wipes?
  9. JohnKSa

    JohnKSa Well-Known Member

  10. Telekinesis

    Telekinesis Well-Known Member

    I've heard that the ATF isn't very fond of this design, and I personally don't think suppressor manufacturers have much to fear from adapter designs like these. With the adapter, you're already paying nearly $300 including the tax. I would much rather pay a little bit more for a real can (I only paid $400 for my 9mm pistol can, tax included).

    The ATF has also released a letter stating that replacing consumable suppressor parts (like wipes) is legal. Just goes to show you never really know how they'll rule on a certain matter.
  11. wally

    wally Well-Known Member

    Before you do anything a BATFE "letter" would be wise before you proceed.

    As to the changing the OAL my GemTech Multimount varies a good bit depending on if its got the fixed adapter (like for a 9mm AR) or the LEM for a semi-auto pistol. The suppressor requires a stamp, the LEM and 1/2x36 end cap are just "parts" nothing required other than money to buy them.

    So if your design somehow increases the volume while being recoil booster you should be able to get it approved without requiring a stamp for it.
  12. Montanan09

    Montanan09 Member

    Again, some good points on this subject. Thanks for the meaningful responses. While I had no intention of trying to make any of my own modifications, I see that there is even more legal complexity to the subject than I had thought. I guess that is one reason that manufacturers may not be doing something like this either; possibly because adding to an existing suppressor could cover the serial number and I'm betting that would be a violation of some sort too.
  13. thorazine

    thorazine Well-Known Member

    Based on that I would wonder if it would be lawful to add a wipe to an existing suppressor that did not originally feature a wipe?

    I assume not but since the part is consumable...
  14. dprice3844444

    dprice3844444 member

    anybody got the letter?
  15. joeschmoe

    joeschmoe Well-Known Member

  16. What law says you cannot?
  17. Elkins45

    Elkins45 Well-Known Member

    I wonder this as well. The ATF FAQ says you can't, but a document on a website isn't the same as reading it in the law.

    Still, I have NO desire to be the test case!
  18. MasterSergeantA

    MasterSergeantA Well-Known Member

    Isn't that always the question? Probably no specific "law", but a series of "decisions" and/or "opinions" coming out of BATFE technical branch. Are they "law"? No. Some of them seem capricious and some change. But do you want to ignore them? Your call.
  19. joeschmoe

    joeschmoe Well-Known Member

    We know they say you can't repair or replace parts. When dealing with restricted NFA items you should assume you need to walk a fine line to stay legal. Not assume that everything is legal unless clearly forbidden. Ask over at silencertalk.com for a more specific answer.
    As with most things, it would probably come down to why are they looking to charge you. If they have no reason to look at you, then who cares? If they are already searching your house for some other reason and hoping to find something to make a case out of, this could be it. With NFA you don't want to get caught in a grey area.
  20. JohnKSa

    JohnKSa Well-Known Member

    Both true statements. However, the latter misses one important point. The document on the BATF website may not be the law, and therefore operating in a manner contrary to the document's contents might not put you in jail. BUT, it does provide valuable insight into what the BATF considers an infraction and lets you know what they would attempt to prosecute.

    That prosecution might not be successful if their interpretation, as stated in the website document, strays too far from the court's interpretation of the law. That said, unless you have a lot of spare time & money to spend in the court system, it would be wise to pay attention to the FAQ contents.

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