NFOA MEMBERS FORUM
General Categories => The NFA Corner => Topic started by: bkoenig on July 04, 2012, 12:32:16 PM
-
OK, here we go. For anyone who's not familiar with this process, it is legal to build your own suppressors. The legal requirements are identical to building a short barreled rifle (SBR) or short barreled shotgun (SBS). You fill out ATF Form 1 and pay a one time tax of $200 to Uncle Sam, and send it all off the the ATF. After a LONG wait (mine took 6 months) if everything is in order you will receive your form back with a tax stamp. Once you have the stamp in hand you can legally begin construction. Building any part of the suppressor, even a single baffle or threading a tube, before that time is illegal and will land you in the graybar hotel if you get caught. $200 is a pretty cheap price to avoid having a really friendly guy named Bubba as your room mate. Don't be stupid.
I will be building a .22LR suppressor. It will be built out of 6061 Aluminum, except for the first baffle and the barrel threads which will be 303 Stainless for durability. Aluminum is fine for a rimfire suppressor, but is not strong enough for centerfire. The baffles will be what is known as a "K" baffle, because when they are viewed from the side they look like two K's back to back. This baffle type generally works well for subsonic and low pressure loads, but it is a little more complicated to machine.
Quick disclaimer: I am not a professional machinist. In fact, I'm not even a particularly good hobby machinist. I will most likely make mistakes in this build. Build a suppressor can be dangerous, both from running machine tools and from using the suppressor itself if it's not properly constructed. Don't attempt this without a full knowledge of the risks involved. I'm not responsible for your safety.
With that out of the way, let's start turning metal. I turned down a bar of aluminum to 1.027", which makes for a slip fit inside the tube. I don't want it too tight, as rimfire ammo is very dirty and this will need to be disassembled frequently to clean it out. The bar has been drilled with a .25" drill bit. I may make the final bore slightly bigger, depending on how my tolerances stack up.
6061 machines beautifully. A sharp bit finishes it to a mirror finish. Also, the chips are extremely sharp. I have a sore index finger to prove it.
(http://i1226.photobucket.com/albums/ee412/alemonkey/suppressor/IMAG0232.jpg)
-
Next steps - cutting the front "disk" of the baffle. Since I already had the bar chucked up between centers I just left it there for the first one. This was a mistake since I had to then part it off and rechuck it to hollow out the inside of the cone. The next one I'll be smarter.
(http://i1226.photobucket.com/albums/ee412/alemonkey/suppressor/IMAG0233.jpg)
-
Cutting the outside of the cone. The compound is set at 30 degrees to create a 60 degree cone. I didn't get any pics while I was machining the inside, but this is where I was dumb and had to part it off and rechuck it.
(http://i1226.photobucket.com/albums/ee412/alemonkey/suppressor/IMAG0234.jpg)
-
And here's the (almost) finished baffle. I still need to plunge a 1/4" ball end mill into the face and from the back to create a "scoop" in the face and a vent in the back cone. This will vent gasses to the outside of the cone. It's a little hard to explain but will make sense when I have pics. 6 more baffles to go.
(http://i1226.photobucket.com/albums/ee412/alemonkey/suppressor/IMAG0237.jpg)
(http://i1226.photobucket.com/albums/ee412/alemonkey/suppressor/IMAG0236.jpg)
-
How did you learn to make this before you undertook the project? Did you take apart other suppressors and look at them or did you find blueprints somewhere? If/when I get the tools this would be of interest to me.
-
I did a lot of reading and asking questions on the silencersmithing forum over at www.silencertalk.com (http://www.silencertalk.com). There are a lot of very experienced builders there, so if you're interested that would be the best place to start.
-
Looking good Brian; keep up the updates and pics!
-
Ok, all of the baffles are done except for drilling the vent holes. I had to order a 1/4" ball nose end mill for that. A 6 month wait and I didn't get around to ordering a $12 tool until now :angry:
The top baffle is the blast baffle, which is closest to the muzzle of the gun. It's stainless steel and is about 50% thicker all around to make it more durable. The face of each baffle has a groove machined into it for the cone of the next one to fit into. I'm not sure if that was really necessary but I figure it should help keep things straight inside the tube. Next up, threading the tube and machining end caps.
(http://i1226.photobucket.com/albums/ee412/alemonkey/suppressor/IMAG0240.jpg)
-
Looking good Brian!
-
BK, will you get your suppressors done for the NFOA meeting coming up? is there anyway i could put a few rounds in them if you're going to the meeting?
-
Sure, I should have the .22 done in the next week or so. Is your Mosquito threaded 1/2-28?
-
i have an adapter for it. otherwise, its some weird metric crap.
-
Sounds good, we'll give it a try.
Got the tube threaded for endcaps tonight. This was the part I was most nervous about, since I had to use a steady rest for the first time. And my steady rest is a home made job. It worked ok, though, so now it's on to the endcaps. My ball mill also showed up, so I can cut the scoops and ports into the baffles. The baffles also may need a slight skim off their outside diameter since they're fitting really tight in the tube right now. Once they're all crudded up there's no way they'll come out when they're this tight.
-
bk, have you seen these:
Oil Filter Suppressor-FULL AUTO (http://www.youtube.com/watch?v=haiqFcIXTqs#)
-
I've seen them and honestly I don't see the point. If I'm going to wait 6 months and pay $200 for a stamp I'm going to do it right. Also, the ATF considers replacing a baffle to be the same as building a new suppressor, which will land you in the pokey. It seems to me that screwing a new filter on would constitute a baffle replacement in the ATF's eyes. NFA regulations are completely arbitrary and subject to the whims of the government so I couldn't say for sure, but that thing seems legally dubious.
-
More progress over the last couple of days. Got the tube threaded and both endcaps threaded to match. The mounting threads are also done. The end caps still need profiled to match the outside diameter of the tube, and the aluminum one still needs shortened. I still need to do the vent holes in the baffles and do some final fitting on them, make a spacer to hold everything in place inside the tube, engrave it, and apply some sort of finish. I'm kind of tempted to go with a brushed metal finish, maybe by spinning it in the lathe while holding some emory cloth up against it. It's finally looking like a real can:
(http://i1226.photobucket.com/albums/ee412/alemonkey/suppressor/IMAG0243.jpg)
And yes, I did run around the house tonight with it making "Pew! Pew! Pew!" sounds.
-
And yes, I did run around the house tonight with it making "Pew! Pew! Pew!" sounds.
Yes, but did you hum the 007 theme???
Seriously though, the can's looking pretty. I'm looking forward to a range report once you get the final punch list finished!
-
Looks reallly good so far..
Might i suggest getting a longer handguard and tucking the suppressor.
(http://i765.photobucket.com/albums/xx292/srt-4_jon/2012-02-28205040.jpg)
-
I think I'm going to go the other way - shorten the barrel to 4.5" to keep bulk ammo subsonic. That should put the back end of the can right up next to the front of the rail. I can't decide if I want to do that myself or send it off to Adco. They'll do it for $65.
-
My gun is a 4.5" barrel with a 6" suppressor on it.
If you do plan to chop and re-thread, might Isuggest Long Range Precision. I had them do a barrel for me and it cost a whopping $20+shipping.
-
You might also check with Exeter Arms.
Still looking sweet Brian, waiting on YouTube video...oh wait, i'll just go to the range with you lol!
-
My gun is a 4.5" barrel with a 6" suppressor on it.
If you do plan to chop and re-thread, might Isuggest Long Range Precision. I had them do a barrel for me and it cost a whopping $20+shipping.
I will definitely look into that. That's dirt cheap, as long as they thread it concentric to the bore. Where are they located? I did a quick google search and didn't find them. I thought about a longer handguard, but I wanted to keep this as light as possible because this is my daughter's favorite gun.
By the way, your loading bench is WAY more organized than mine.
-
LRP is in TN. Ill get you their contact info when I get to a computer. The threading the did on my guns are good to go. They did a savage mk2 and a ruger mk3 for me. The ruger consisted of a sight relocation, cut to 4", re-crown, thread, and matching thread protector for $65.
My bench just looks organized, luckily Iam not zoomed out or you will see the real mess.
-
No new pics tonight but I got the endcaps profiled and knurled, fitted the baffles, and made the spacer. Now I just have to drill the vent holes in the baffles and get it engraved.
-
It's done! Except for paint. Heading out to the range now....
-
I'm back from the range and pretty happy with how it turned out. My .22 SBR is one of the loudest .22 rifles I've ever heard. With the can on it is much better. Bulk high velocity ammo still makes quite a bit of noise because it's going supersonic. You hear a "bang" from the bullet breaking the sound barrier a split second after pulling the trigger. Without a can it's not noticeable, but you can definitely tell when shooting suppressed. The action on this gun is also very noisy. Even with all of that it's hearing safe when running a can. I need to get my Savage .22 bolt action threaded and see just how quiet I can be.
I bought some CCI subsonic rounds, but they don't have enough power to cycle the action. That's too bad, because they're stupid quiet. All you hear is the sound of the action cycling. I'm going to try some other brands of subs to see if they'll work. The CCI's are the Quiet 22 brand which is only running about 700 FPS. That's way slower than needed, so I'm going to find something that runs just a little faster and save these for the bolt gun.
Here's some gun porn. Ignore the ugly guy and concentrate on the shiny can.
Federal bulk pack, 5 rounds without suppressor and 5 with a dry can. Notice I wasn't wearing hearing protection without the can. Stupid move on my part. This thing is LOUD.
http://s1226.photobucket.com/albums/ee412/alemonkey/suppressor/?action=view¤t=VIDEO0011.mp4 (http://s1226.photobucket.com/albums/ee412/alemonkey/suppressor/?action=view¤t=VIDEO0011.mp4)
Federal bulk pack, 5 rounds without suppressor, 5 rounds with wet can. When I'm shooting suppressed you can hear someone in the next range over (about 100 yards away) shooting. The sound of their shots is about the same as mine:
http://s1226.photobucket.com/albums/ee412/alemonkey/suppressor/?action=view¤t=VIDEO0014.mp4 (http://s1226.photobucket.com/albums/ee412/alemonkey/suppressor/?action=view¤t=VIDEO0014.mp4)
CCI Quiet 22 subsonic, 1 round:
http://s1226.photobucket.com/albums/ee412/alemonkey/suppressor/?action=view¤t=VIDEO0015.mp4 (http://s1226.photobucket.com/albums/ee412/alemonkey/suppressor/?action=view¤t=VIDEO0015.mp4)
-
Awesome job Brian
-
You need try Winchester Dynapoints, do not waste your time with Remington Subsonics.
-
Thanks, I will look into that. Remington anything is junk when it comes to .22 ammo. This gun will eat anything (not counting the CCI Quiet that is just under powered) except for Remington .22 ammo. Their QC is so bad that about one round out of 30 or so won't even chamber. My 10/22 won't run with it either.
-
Very Nice!
-
thats fantastic Brian! I do have a soft spot for suppressors, my wallet just doesn't support my desires lol.
-
sweetness BK! i would love to try my 22SBR upper and mosquito with your suppressor if we both make it to the upcoming NFOA meeting. im going to bring a wide variety of 22 ammo.
-
If you come to the vintage rifle match next weekend I'll bring it....
-
ill be out town. going tubing, otherwise i would.
ps - i just bought my barrel. should be here in a week or two.
-
What barrel did you end up going with?
-
CMMG 6.5" barrel with SS collar. i ordered and paid for it Monday and the sent me a message later that days saying it was going into production. I should get it within two weeks, which is really close to my bday! so BK, ill need some help putting a barrel to an upper. ;D i don't know what kind of handguards ill go with, but i think they will be rails, but not sure how long. ill have to think about it.
-
C'mon now, tell the truth. You didn't build that yourself. The One has told us that others, probably .gov, did it for you.
-
Ha! The metal chips embedded in my fingers say otherwise. My boss, who started our company from nothing 12 years ago with our other cofounder, was pretty angry about the Dear Leader's speech. I believe his exact words were "F*** You."
Off topic, but while it's true that our national infrastructure helps enable entrepreneurs, this whole episode illustrated what Obama thinks about private business. He sees it as a parasite that drains resources from the rest of the country. Not surprising from someone who has never held a job in the real world.
-
(http://25.media.tumblr.com/tumblr_m7d7rkXYI81qhiuu9o1_500.jpg)
http://didntbuildthat.com/ (http://didntbuildthat.com/)
-
LOL :laugh:
-
That's FUNNY rahwt there!
-
Busy evening tonight. After dinner I decided to take apart my Savage MKII bolt action and get it ready to thread the barrel tomorrow. After I had it apart I decided I might as well get it chucked up in the lathe. One thing let to another and now I have it cut back to 18" and threaded. We'll see how it shoots tomorrow.
I also slightly enlarged the bore diameter in the can. It was right at .25", and I was starting to wonder if that was too tight. I was shooting out to 50 yards today and it looked like some of the bullets may have keyholed. After talking about it with some other guys I started wondering if the tight bore was affecting bullet stability. So, I stepped up to a 17/64 drill bit (.265) which is actually what the guys at Silencertalk recommended.
-
Round 2 has started. Just a little bigger than the first one.
(http://i1226.photobucket.com/albums/ee412/alemonkey/suppressor/IMG_1777.jpg)
-
Got the big brother done today. Probably will be a few days before I have a chance to try it out. This one was a lot more work. Stainless is a lot harder to machine than aluminum, especially with a little benchtop lathe.
(http://i1226.photobucket.com/albums/ee412/alemonkey/suppressor/IMG_1783_zpsc8f4f059.jpg)
-
Baffles:
(http://i1226.photobucket.com/albums/ee412/alemonkey/suppressor/IMG_1791_zps6d20d1b6.jpg)
Drilled out the back of the mount to save a little weight. It's still a heavy pig. I overbuilt it.
(http://i1226.photobucket.com/albums/ee412/alemonkey/suppressor/IMG_1785_zps1bf23a69.jpg)
-
nice! time to get that deer permit.....
-
Brian, that's pretty freaking sweet! Bringing it to the meeting this weekend?
-
Brian, that's pretty freaking sweet! Bringing it to the meeting this weekend?
I don't think I'm going to make it. Mother In Law's birthday. If I can go it will be a last minute thing, but I'll be sure to bring it.
-
I don't think I'm going to make it. Mother In Law's birthday. If I can go it will be a last minute thing, but I'll be sure to bring it.
Mother In Law's birthday? Unless there is free beer and fireworks I rank that holiday just below Arbor Day :D
You must be banking on an inheritance.
-
It's called keeping the wife happy. :D
-
Bring the MIL out with ya. The Lil' one can teach grandma how to shoot 'her rifle'. ;)
-
It's called keeping the wife happy. :D
A happy wife means a happy life!
-
on the subsonic .22 ammo. I have found rem subsonic to function perfectly in my suppressed UZI subgun with .22 conversion.
-
Performing some thread necromancy here.
I picked up a Remington 700 AAC-SD this winter and dropped it into a Bell & Carlson stock. I've only put 50 rounds through it so far, but it's shaping up to be a sub-MOA rifle with the loads I've tried so far. I need to track down some heavier bullets to take advantage of the fast twist (1:10) and see if that will shrink my groups some more, but right now it's hovering between .75 and 1 MOA from a bench. I'm not a very good bench shooter, so I'm sure someone more skilled could do better. I'm much more interested in shooting from positions, so once I get a good load worked up I want to do some long range shooting from prone.
Anyway, while I was breaking in the barrel I shot it without the can, but I bought this specific model because the 20" heavy barrel is threaded for a suppressor. Last weekend I stuck the can on and headed to the range. I saw no change in accuracy, but the point of impact shifted down 4 MOA due to the extra weight on the end of the barrel. The big change was in how pleasant the rifle was to shoot. This is a heavy rifle with a thick recoil pad, so recoil was mild to begin with. Now it's a pussycat. The reduction in noise was the best part. I wouldn't consider it hearing safe, but it made shooting it much more enjoyable. I was shooting under a tin roof and an unsupressed 20" .308 is LOUD. This got rid of all the muzzle blast and turned the "boom" into a loud "crack". I think I need to build another 308 can for my Blackout so this one can stay on the .308. I purposely overbuilt this one so it would hold up to .308, so I could build a dedicated .300 BLK can much lighter.
(http://i1226.photobucket.com/albums/ee412/alemonkey/AA495218-6C97-438B-B69C-457333F7DDAC-7606-000005842A7D378D_zpsd2306a26.jpg)
-
I find the lack of concussion as much an improvement when shooting as the noise reduction. After shooting with a can for a while it's really unsettling to shoot with out one
-
The big change was in how pleasant the rifle was to shoot. This is a heavy rifle with a thick recoil pad, so recoil was mild to begin with. Now it's a pussycat. The reduction in noise was the best part. I wouldn't consider it hearing safe, but it made shooting it much more enjoyable.
I eventually want to put a supressor on the "The Kids' Deer Rifle" (a Ruger Frontier in 7-08) for the same reason ...... Right now, I make reduced loads for it (139 and 150gr bullets @ 2300-2400 f/sec) ..... I'd eventually like to run heavier bullets (Speer 160 BT and mayber 168 Bergers) when they get older ......
-
I like the finish on that stock. How much did the stock run you?
-
It was $220 from Red Hawk Rifles. I offset half of that by selling the crappy Hogue stock that came with the rifle on evilBay. The finish is just Krylon Fusion, but I'll probably duracoat it at some point.
-
That's cheap. I'll have to look more in to those stocks. I would love a McMillan A4 but man that's a lot of money.
-
I was very impressed with this stock for the money. It's solid, if you ran out of ammo you could beat something to death with the giant hunk of fiberglass. It has a steel bedding block that runs all the way past the front sling swivel, so it's not going to flex at all. I bedded this one with acraglas to really lock everything down.