Which Solvent Trap is Right For Me?

It’s surprising how complicated this little thing can be… Lets start at the top.

Which do you value more; performance or convenience?

Convenience: If you don’t want to do any work at all, want it to be cheap and disposable, buy it for a few bucks, cash, pretty much anywhere; then You want the S36SA or the S37SA series of Oil Filter Solvent Trap Adapters. They usually cost $6 or less, Oil Filters are everywhere for under $5. Their performance is mediocre, but they’re cheap and you don’t have to do anything. Filtration is kinda OK, because the microns are fat. It’s a compromise.

Performance: You want the 4003 Fuel Filter Solvent Trap Adapter. Also available as a Muzzle Brake and/or Flash Hider. You’ll have to do a little work to get it to perform, but oh baby, when you do… You can filter below 1 micron using toilet paper, if you want. But, it costs more and it takes effort. Even better, the adapters come in multiple thread types, so you can use the same 4003 on every gun you own. You don’t have to buy a cap for every thread type you’ve got… Just an adapter and you can leave it on the gun because it’s also a muzzle brake/flash hider. Does it get any better?

“But what about the flashlight adapters I see advertised?”

I could make them, but I don’t. And, for good reasons.

I’m not saying they’re bad… They’re just not as good, and I’ll tell you why.

First and most obviously; flashlights are not filters. Have you ever cleaned or filtered anything with a flashlight? Get it? If you buy one of those, we all know what you’re really up to… I prefer thicker ice, and that my equipment be multi-purpose. As the law is written, that’s two birds with one stone for the 4003 filters. Flashlight scores zero on both counts. Oh, and it comes with a stack of Freeze Plugs? Really? Convenience meets stupidity…

Most of these fleshlight flashlight adapters are not even capable of being used as a flashlight. And more, why would you want to trash your flashlight when the shit hits the fan? I’m quiet, but I can’t see anything…

Form 1/NFA applications? First, lets talk about legalities. If you wish to re-purpose a solvent trap into a silencer/suppressor, it seems the ATF is letting that slide. Anyone who has been in the Silencer biz for a long time can tell you that the ATF has always said that Form 1 builds need be completed entirely by the Form 1 Applicant. There is no 80% gig with NFA. In spite of this, you can mosey on over to silencertalk.com and see a bunch of Form 1 builds done with re-purposed, pre-manufactured products and materials. It seems like the ATF will let you do pretty much anything as long as you pay your $200 and piss all over your Bill of Rights. That isn’t to be taken as advice. I’m just saying, hey, look, everyone else is doing it, and none of them have been thrown in jail, so, yeah.

My angle is WRL/EOTWAWKI/SHTF. Prepper territory. When society goes to shit and there, functionally, is no more NFA. That’s why I prefer the slightly larger diameter of the 4003. When the electricity is out, and you never owned a giant $100,000 CnC Lathe and Mill, and never had a 1500sqft garage to put them in to begin with; you can’t build fancy stuff like K-Baffles and Monocores. You’re in a “crude, but effective” situation. You need something that you can make with minimal tools and resources, and it better damn well work.

Why do I prefer the 2in diameter 4003 filter? It is radially only 1/4 of an inch, or less, larger than your average flashlight thing, but, volumetrically, it’s much, much larger inside.

Who cares?

You do, when the lights go out.

Now we come to the physics lesson.

Silencers do one thing; convert physical kinetic waves of energy into heat. They do this in two ways; expansion chamber(s) and deflection. This is why they get so hot. It’s not just muzzle blast. All that noise is being converted into heat when it hits the walls of all the internals. You can’t get rid of sound. You can’t get rid of energy. All you can do is convert it from one form to another.

Where’s your fancy CnC mill and lathe? Don’t have either of those? Well, you’re not going to be making good use of deflection. K-Baffles and Monocores are off the table for you. These designs are what allow a silencer to be small and effective at the same time. You can’t do them. So, you’re going to have to compromise a little.

Oil Filters are just a bigass expansion chamber. Maybe even a buffered expansion chamber if you count the filter media, but that really doesn’t do a lot. Getting the picture?

If you’re stuck with making internals that aren’t fancy schmancy, you’re going to need a larger internal volume to make up for the fact that you don’t have access to fancy schmancy (4003); but you do have access to something.

You could use stainless steel washers with PVC Pipe spacers. Or Freeze Plugs. They deflect, not as well as K-Baffles or maze-like Monocores, but they do pretty well. Make them 1/2in larger, diametrically, and they more than compensate in volume for what they lack in deflection. It actually does a better job than the exotic stuff, simply by giving up that 1/4in. You are now operating with “crude, but effective” and doing a better job than if you had access to fancy schmancy.

What about a perfectly legal, re-purposed Form 1 build? Well, aside from that fact that it may or may not actually be legal to do that, it is clearly observable that the ATF is allowing it. The catch is that you are not allowed to repair your own internal parts once you’ve made them. A weird technicality of the law requires that a Class 3 SOT perform Silencer repairs even though you built the whole thing your self in the first place. Stupid, yes. The Law, yes. Since when did you really expect the law to not be stupid? Look who wrote it…

This is why legal silencers are often made with super-durable exotic materials. Titanium, Inconel, and 17-4 PH Stainless Steel. OK, 17-4 isn’t that exotic… Silencers are, by their nature, consumables. They don’t last forever, and nobody with a brain could expect them to. You run out of silencer just like you run out of ammo. In a WRL/EOTWAWKI/SHTF circumstance, this doesn’t apply. You can fix/repair whatever you feel like, so, less durable but abundant/available materials are just fine. But, while the NFA is in effect, you’re out of luck.

But, how would anyone know?

How would anyone know if you used an Oil Filter as an illegal silencer? How would anyone know if you replaced the PVC spacers in your Form 1 Silencer yourself? How would anyone know if you did all of it illegally? I mean, it is a silencer, right? Who’s gonna hear it? Unless your dumb ass blabs, who would ever know? Why should any rational person care? It’s kinda stupid. I’m not suggesting that you break the law, just demonstrating the stupidity of it.

Look at it another way; why do we make laws that cannot be enforced? Another good example is the Law regarding Concealed Carry in Bars in the State of Floriduh. You’re not allowed to carry concealed in a bar in Floriduh. But, it’s concealed, so… How would anybody know? Why does merely being in a bar matter? I don’t drink. I’ve been in a few bars. That’s where the pool tables are… Try to find a pool table in a place that is not a bar. I dare you. That’s why we call it Floriduh…

Silencer laws are just as stupid. It’s a chill on basic safety equipment. Lets all grab our guns and put on earmuffs so we can’t hear anything! Yeah, that’s brilliant! We’re operating potentially deadly machines and can’t communicate! Why are we not just putting mufflers on these things, like sane people would do? That’s the point… To cause dangerous problems. It happens at a gun range almost every day. Range officer calls the line cold, people start going up to check/replace their targets, some guy who didn’t hear pops off a round with warm bodies downrange… Earmuffs. Fuckin’ dumb. Or is it? It doesn’t take much to figure out most gun laws are about causing problems, not solving them. They’re not dumb, they’re evil. Cause a problem with gun control, then come up with some more gun control to fix the problem caused by gun control… Anti-gun freaks set up their own children for slaughter just as an excuse to grant their political faction more power. What do you expect from people like that?

I’ve had to back-burner most of my Sulphur-less BP experiments, so I haven’t been doing a lot of filtering lately. Surely, when the lights go out, you don’t want to be wasting what little solvent you’ve got. Even in current times, with ammo short and expensive, nullifying it with old-school black powder is dirty. You can’t just go wasting the stuff. When the dumb animals masquerading as people lose access to the conveniences that they’re too stupid to live without, and they start their rioting and pillaging, you might just need a quick, effective silencer, too. A 10/22 with an S373 filter on it, sub-sonic ammo, sub-sonic twist barrel, registered adapter holding that S373 on… Less noise than a BB gun. The lead smacking the target is the loudest aspect. When SHTF, are people raiding auto parts stores for oil filters? Probably not… Do you want to keep going back to get another filter every few hundred rounds? I don’t… That S373 might last a while on your .22lr, but on your 7.62×39 or .223? Nope. You’re gonna need something better than an oil filter if the lights go out for more than a  day or two.  I got plenty of washers and PVC pipe around here if I need it, and I can make my own Sulphur-less black powder… 4003.

Common Gun Thread Combinations

This is a list of the more common thread associations. If you have one of these, then the threads are probably what is stated here. This is by no means exhaustive or guaranteed. There is nothing that forces Gun A to have Thread A. You should always double check. There is always a chance the barrel was originally un-threaded and someone put who-the-hell-knows-what threads on it. Guns that don’t come from the factory threaded, or at least with that option, are likely to be unguessable. You’ll just have to find out the old-fashioned way. Yes, I just made up the word “unguessable.”

AR-15 .223/5.56mm – 1/2-28
AK-47 – M14x1LH
AR-15 9mm – 1/2-36
AR-15 RRA .458 SOCOM – 5/8-32
AR-15 WC .458 SOCOM – 11/16-24
AR-10 .308/AR-15 .300 AAC Blackout – 5/8-24
M14/M1A – .595-32
1911 .45 – .578-28, .575-40, or M16x1LH
Glock .40 (conversion barrel from larger caliber)/.45 Cal. – .575-40 or .578-28. Can be M16x1LH (or some other weird stuff) if euro barreled
Glock .40 – 9/16-24
Glock 9mm – Mostly 1/2-28, but sometimes M13.5x1LH if euro barreled
FN FAL Inch (L1A1)/MP-5/M1 Carbine – 9/16-24, maybe? Sometimes?
FN FAL Metric – 9/16-24LH (occasionally these are off-the-wall metric, but that’s pretty rare. My STG-58 is 9/16-24LH)
HK SOCOM Mk.23 – M16x1RH, weirdos…
Walther P22 – M8x0.75 recessed
GSG 1911 .22lr (and the SIG copy) – M9x0.75 recessed
Umarex .22lr rifle, and the assorted rebranded versions thereof – M8x0.75- the Walther P22 adapter would work, but odd
SIG Mosquito – M9x0.75
SIG P220 .40/.45 – .578-28
SIG P226 – M13.5x1LH
HK G3/53/HK91/HK93/PTR91 – M15x1
Cobray/MAC/etc… M-11/9mm and most clones – 3/4-10
Steyr AUG – M13x1LH
Yugo PAP/MPAP/92 w/ “big weird threaded thingy” – M26x1.5LH
AK-74 w/ “big weird threaded thingy” – M24x1.5RH

If you have something odd or unguessable, please don’t ask me to guess, too. I’m some dude on the Internet. How can I possibly have more information than you, the owner, who is holding it in his hand? Guessing in person is better than guessing over the Internet. I’ll try to help where I can, but don’t get mad if it’s wrong. I have no idea how many fingers you are holding up right now… Maybe just the one in the middle? ;-)

If you have any additional information or corrections, feel free to post a comment.

“I need a screw for my car. It’s a blue car with tires. WHY WON’T YOU HELP ME!!! YOU SUCK I HATE YOU!” Would you really expect any non-telepathic person to figure that out? I’m trying to help, but you gotta give me at least a rational hint…

“I wish you would just tell me. Why do you have to make it so hard, I’m trying to give you my money!” I wish there were a simple answer, but there isn’t one. I could lie to you… Nah, I couldn’t.

I’m not the one who made it this way. A world full of jerks who want you to have to buy special threads at $[too expensive] from them made it this way. I’m trying to undo it. There are tons of ridiculous threads out there, and none of them have any rhyme or reason, many have no published specs at all. They’re just plain made-up. Others are done poorly by a drunk guy on a sloppy manual lathe and don’t fit what they claim to be. There’s a world of crap out there…

Here’s an excellent example. Mk23. M16x1RH. The same company makes plenty of guns with the normal M16x1LH. Why did they do the Mk23 backwards? It’s the only one in the world like that, and it even defies their own conventions because they make plenty of other guns that have to proper thread…

There are standards and then there are “common conventions.” There are no standards that dictate a certain thread on a certain make/model/caliber of gun. There are common conventions, but there’s no guarantee that they were followed on your gun.