Going to do a rimfire can

[Gunfixr]

Ok, so I got my multi caliber centerfire can done, and it works as well as hoped, better in some ways, especially considering the multiple calibers I wanted to use it with.
It's size though, pretty much precludes its practical use on a .22lr.
So, I'm going to do a dedicated .22lr can. About to send in the F1, will be e-filing, so it won't take all year.
What I want is something pretty compact, in the 4" to 5" long range. It'll be for a small pistol and rifles. I mostly shoot full velocity bulk pack ammo, so that is what it will see most of. I will run some subsonic through it occasionally, most likely target velocity.

I see around that K's are the way to go, but I have also seen that K's work well with subsonic, but others work as well with HV ammo.
So, which would be best? I was maybe thinking monocore or K's, but can go cones, or even something more unique. Don't have cnc, so can't go totally crazy. Looked through most of the completed .22 builds in the build thread, there was one with a large front chamber with a center bore tube and a star shaped diffuser.

I'd rather it work well with HV, and at least work decently with standard velocity ammo. I can go a bit longer, but do not want more than 6" long. I'll have to verify, but 1" OD is pretty doable, maybe a bit more, gotta check the pistol sights height over bore.
I have aluminum (with SS blast baffle), but can and will, if better, get Titanium.

What say the gallery?

[Gunfixr]

Crickets chirping...................................

43 views and nothing.
I don't want somebody to design my suppressor for me. The general consensus is that K's are best for rimfire, but for a few dissenting votes that not for HV ammo, subs only.
So, all I want to know is from someone who has made both, or has access to both, which type is better on HV ammo, Ks or others, in a shorter can (4-5")? I can do anything and make it huge, just don't want that.
I will design my own core if monocore is the way to go, or if something other is the way to go. Clearly Ks are already designed.

[Capt. Link.]

You want K baffles for HV or subsonic.
You can't hear a suppressed chirp.

[BinaryAndy]

K baffles do their best work with relatively low pressure rounds, that's one of the reasons nobody uses them on centerfire rifle cans. They work very well for 9mm and 45, which both have a whole lot more pressure at the muzzle than any 22lr, HV or not. I don't see any reason why the projectile being slightly supersonic would make much difference as to whether K's are a good choice or not.

In any case, in a pistol, even relatively fast 22lr is probably going to end up subsonic (unless you have an unusually long barrel).

Good K's tend to be a little more efficient than monocores, which would make them my choice for trying to get a small can quiet. 1"x5" really isn't much smaller than the industry standard anyway.

It's also a whole lot easier to make good K baffles than a good monocore without CNC.

Good luck.

[T-Rex]

As you stated as well as others, K's will be the way to go.
I don't see 5" doing what you want, at least not with HV ammo.
My stack (9-nested K's) was 5.2" plus end caps = about 6" +/-
With anything in a 4.5" pistol, it was quieter than my AAC Pilot
On a 16" semi-rifle, it was definitely hearing safe, but noticeably louder than the pistol w/ HV's
I tested it with: CCI Std, CCI Mini Mag, Rem Sub, Rem Yellow Jkt, Win Super X, Win WildCat, Federal Bulk and Super Colibri
I have about 1/8" of distance for a "blast chamber" and I noticed no FRP what-so-ever.

Not sure how quiet you are trying to get to, but If I where doing a rifle, based on my previous design and intended for HV, I would add an inch to get 2 more K's. My build was 17-4 muzzle cap and blast K, 7075 K's and 6061 Tube and end cap. I'm not sure I'd notice an added inch, as far as weight and length go.

[whiterussian1974]

As you stated as well as others, K's will be the way to go.
I don't see 5" doing what you want, at least not with HV ammo.
My stack (9-nested K's) was 5.2" plus end caps = about 6" +/-
I'm not sure I'd notice an added inch, as far as weight and length go.

Do you really mean "nested" or "sequential?"
Nested means that each fits inside the next, with the outer containing all others.
Sequential would be 1 after the next.
Nested is usually only used for coaxial tubes fitted w cone tips.
Ks would be almost impossible to nest in any version that I can envision.

As for extra inch being noticable. I've always found that it's better to have extra and not need it, than the obverse. You can always cut the extra length off if you later decide. You can't add it.
And while many people say that they don't need that extra inch, they usually like it better if they have it.

[gunny50]

Ks would be almost impossible to nest in any version that I can envision.

Several manufacturers did that, including for 22r. and large calibers

Huntertown


B&T did it with a separate spacer. one can machine it to the blast-plate as one part.

many solutions are possible, like the alpine, etc etc


Gunny

PS see you all at Shot not week.

[Capt. Link.]

Ks would be almost impossible to nest in any version that I can envision.

Several manufacturers did that, including for 22r. and large calibers

B&T did it with a separate spacer. one can machine it to the blast-plate as one part.

many solutions are possible, like the alpine, etc etc

Gunny

K baffles have a long successful history with HV full power military calibers.The nesting was used to reinforce the baffle stack way back in the 1980's before they were called "K's"

[whiterussian1974]

Ks would be almost impossible to nest in any version that I can envision.

Several manufacturers did that, including for 22r. and large calibers
B&T did it with a separate spacer. one can machine it to the blast-plate as one part.
many solutions are possible, like the alpine, etc etc
Gunny

You posted examples of sequentially coupled.
These are examples of "nesting:"

[T-Rex]

For the sake of argument, if a novice were to stumble upon this site and ponder about "nested k's", they would google and see these:



Now, im not saying google is god, but it does set a precedence for common usage.

Anyway, this style is what I was referring to.
Russian, I agree about the extra inch being lost to some.

[Gunfixr]

Thanks Guys, that was what I needed to know.

Looks like it will be Ks then.

We had an Alpine in the shop for sale, but we normally don't shoot the new suppressors, so I never got to test it. The buyer used to come shoot it out back while waiting on his form 4, but always with subsonics, and always on a pistol. I didn't think of this back then, hadn't even finished the other suppressor.
I did take it apart one day, it's full of Ks, I think they were nested. It's about or just over 4" long.
I have one pistol, a small PPK sized thing made by Bersa. I've had other pistols, don't know if I'll go back to Rugers or others. This one is perfect fit for my daughter, which is why I got it. It's kind of why I want this suppressor smaller, so as not to be unwieldy on this small handgun. However, I do have a threaded 10/22, and a threaded tube fed bolt gun, and another mag fed bolt gun I will probably thread, so more rifles than pistols.

If, say, a 6" long suppressor will be that much better, I can go with that. I don't really want to go more.
I just need to register with the e-file site, and scan my Trust, and I'm ready to file the form 1.

I already have all the aluminum I need to make a tube and baffles, but I won't be anodizing them. I am concerned about oxidation of the aluminum, or is that a waste of time?
I can do a SS blast baffle.
Or, I can order some Titanium and do the whole thing.
I am seriously considering replacing the steel spacers in the multi caliber with Titanium ones anyway, before the 02 runs out, and so would making an order.
The 02 runs out later this year, before the SOT, and we're not renewing it. We just don't do enough to justify the ITAR payment, and we've already heard they're looking into more complete enforcement on that. It's why I'm doing this on a Form 1, and want the best design the first time. There won't be any replacing parts later.

[Gunfixr]

In a .22, I don't see the need for the extra strength of nesting the baffles.
The only advantage I see is keeping the fouling from the tube, which on a rimfire, would make it much easier to disassemble.
Is a lot of extra maching, though.

Forgot in the previous post. I do want it decently quiet. Obviously hearing safe, but better would be good.
Hollywood quiet would be nice, but if it has to be 8" long or something, I probably won't worry about it.

[T-Rex]

In a .22, I don't see the need for the extra strength of nesting the baffles.
The only advantage I see is keeping the fouling from the tube, which on a rimfire, would make it much easier to disassemble.
Is a lot of extra maching, though.

Forgot in the previous post. I do want it decently quiet. Obviously hearing safe, but better would be good.
Hollywood quiet would be nice, but if it has to be 8" long or something, I probably won't worry about it.

With the term "nested/ing" being used in the design sense I previously described:

I wouldn't look at nesting as extra strength or keeping the tube from fouling.
Will strength be added, yes, but you'll gain space for extra baffles in the same dimensions, which is the whole point.
Will nesting keep fouling from the outer tube, no, the porting will still allow particles to the outer chamber.
Is there a bunch of extra machining, not really. A step of .020-.030 should suffice. On even smaller machines, this is a one pass cut.

As nesting being used in the alternate designs, you are correct in each concern.

I think focusing your design on the baffles face profile, porting size and placement to help get maximum suppression. Aluminum is easy to anodize, at home, for little money and effort. I can pm you if curios. 17-4 baffles are the, likely, next candidate. I dont think you'd be unhappy with the weight of an all SS can on a rifle or pistol.

[plodder]

Quote from whiterussian1974:

As for extra inch being noticable. I've always found that it's better to have extra and not need it, than the obverse. You can always cut the extra length off if you later decide. You can't add it.
And while many people say that they don't need that extra inch, they usually like it better if they have it.

Not true, and I have a recent correspondence from my friendly BATFE "ask the expert" that confirms. If you change the length of the silencer from what is stipulated on your Form 1, you have made a new silencer, requiring another $200 and approval process.

[T-Rex]

Quote from whiterussian1974:

As for extra inch being noticable. I've always found that it's better to have extra and not need it, than the obverse. You can always cut the extra length off if you later decide. You can't add it.
And while many people say that they don't need that extra inch, they usually like it better if they have it.

Not true, and I have a recent correspondence from my friendly BATFE "ask the expert" that confirms. If you change the length of the silencer from what is stipulated on your Form 1, you have made a new silencer, requiring another $200 and approval process.

It clearly states on the atf site that a reduction in length is permissible while an increase would constitute a new silencer.

[gunny50]

Will nesting keep fouling from the outer tube, no, the porting will still allow particles to the outer chamber.

Please take a look at the Alpine and the Huntertown design and these are not the only company that makes K's this way.

The added extension to the front or rear will cover the space between the port in the skirt and the outer tube, so No fouling there.

See the 2nd silencer from the top and last silencer in the lineup of 4.

Gunny

[T-Rex]

Will nesting keep fouling from the outer tube, no, the porting will still allow particles to the outer chamber.

Please take a look at the Alpine and the Huntertown design and these are not the only company that makes K's this way.

The added extension to the front or rear will cover the space between the port in the skirt and the outer tube, so No fouling there.

See the 2nd silencer from the top and last silencer in the lineup of 4.

Gunny

I understand what you are saying, gunny.
my comment was intended towards the "nested k baffle" reference I provided several posts up, not to the pics you were sharing.

I think the extension added to the k's cone/tail would best be used in a segmented/modular design where each piece threded into the next. This would save the weight of an outer tube, reduce fouling and increase volume from the spacers addition.

More machining, but a cool design it is.

[Capt. Link.]

The nested K's used the face of the baffle to strengthen the cone or skirt of the preceding baffle.More weight is saved doing this as well as the density of metal is higher.With well designed Ks Hollywood quiet should be attainable in a 5-6 inch can going to 8 wont help unless the design is poor.

[T-Rex]

Heres a quick, basic design, nested K build.
Face profile can be modified with limited loss to baffle count.

[plodder]

Quote from whiterussian1974:

As for extra inch being noticable. I've always found that it's better to have extra and not need it, than the obverse. You can always cut the extra length off if you later decide. You can't add it.
And while many people say that they don't need that extra inch, they usually like it better if they have it.

Not true, and I have a recent correspondence from my friendly BATFE "ask the expert" that confirms. If you change the length of the silencer from what is stipulated on your Form 1, you have made a new silencer, requiring another $200 and approval process.

It clearly states on the atf site that a reduction in length is permissible while an increase would constitute a new silencer.

I stand (technically) corrected. Here is what the "expert" sent to me:
"Please direct a letter to the NFA branch with specifics of the changes". He then referred me to Q&A answer for "May a repair change the dimensions or caliber of a silencer?" He then highlighted the portion that said "MINIMAL" length reduction is permissible FOR THE PURPOSES OF RETHREADING- U.S.C 922 K

So, true. You can reduce the length of a silencer minimally (whatever that means), apparently only for the purposes of rethreading.

He made it very clear to me that simply hacking off an inch because I wanted to was going to be frowned upon severely.

[Gunfixr]

On suppressor length mods: I have talked with a long time ATF investigator who we know, and he advised me that very minor changes to length for repair purposes was ok, but otherwise no. When I asked what minor changes were, he said there was nothing specific, but 1/4" would be ok, maybe 3/8". Much more than that would get in the gray real quick.
He is one of three agents we know who are consistent with answers, and go on record to say that if any other agent says differently, to tell them that they had told us what was gtg.

I see that there are a couple ideas about what "nesting" is, and I should have clarified what I meant. I was referring to where the skirt has an extension that completely covers to the next skirt, or something like that. If you were to stack them together outside of the tube, it would appear solid, except for the seams where they meet end to end. You would not see the skirts at all.
Just the ends tucked into each other would leave the skirts visible, and the fouling that comes out through the skirt vent would get onto the inside of the tube. Of course, with the ends of the baffles locked together, if the ends of the stack were locked into the end caps, then the OD of the baffles could be reduced slightly, making them easier to remove, and the locked in nature would keep everything in alignment.

If I can get sufficient quiet out of 5", I would like that best, but 6" is acceptable.

I already have the aluminum, and I believe I have some 304 SS with which I could make the first baffle. I can insert a SS bushing for the barrel threads into the rear endcap. Never done any home anodizing. I just don't want them oxidizing together. If I don't order titanium for this unit, I may not bother with the spacers for the other. I have a tool to drive out the spacers for the other, and they are so thin that I would probably only save a couple ounces. The other spacers are steel, and while I coated them, eventually it will come off, and rust will show itself.

Having never made Ks, I will just have to guess at the details. From what I've seen, the skirts/cones tend to be about 60 degrees. The exact thickness varies with caliber/material. A radiused groove around the back face to generate turbulence. The ball endmill into the back face at the bore to make an angle I haven't figured out. I don't know how you straight plunge a ball endmill into something and get an angle. I figured to just set the baffle at an angle, and plunge across the edge of the bore and through the side of the skirt. Just gotta figure the size of the hole/cutout.

[Gunfixr]

Looks like the only other thing to determine is blast chamber. Seems it goes from almost nothing, to a decent sized one. i read about first round pop with too much blast chamber, so I was thinking maybe 1/2" or slightly less.

[a_canadian]

The ball endmill into the back face at the bore to make an angle I haven't figured out. I don't know how you straight plunge a ball endmill into something and get an angle. I figured to just set the baffle at an angle, and plunge across the edge of the bore and through the side of the skirt. Just gotta figure the size of the hole/cutout.

You can just plunge in aligned with the bore and leave it at that, or you can use an actual ball end mill, as in a spherical cutter with a smaller diameter shaft, and plunge then cross-feed to get the undercut. Up to you. Depends on how comfortable you are with that. If you have a decent fixture to hold a K at an angle then by all means go in at an angle if that's what you'd like. There are a lot of variations on this stuff done by various manufacturers.

As for the blast chamber; for pistol keep it short-ish to avoid excessive FRP and compensate for the intensity of that initial blast by using SS for the first baffle. For rifle don't worry too much about it as most of the powder will have burned long before it gets to the blast chamber, so you can open it out as you like within reason. That's my understanding from reading a lot of discussions here anyway.

[Gunfixr]

Well, generally, plunging a ball endmill in next to a bore like that would either give a radius curving down to the bore edge, or a straight wall down to a radius curving down to the bore edge, depending on how deep you went, and how much of the cutter diameter hangs over the bore. There wouldn't be any angles anywhere.

I don't have a problem with the machining, been doing that a long time. Only problem I have anymore is my personal shop isn't nearly as equipped as where I've worked, so sometimes I have to get creative with setups, and some I just don't have.

[T-Rex]

The radius of the ball end creates a "scoop" to redirect the gases. You want to go deeper than the picture shows, so the 2 cuts overlap one another.

You can offset the k baffle in the lathe chuck and put the mill bit in the tailstock. Or make a fixture/jig to offset and lock the baffle into that. Less moving the chuck back and forth.