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Forum 1 22LR/17HMR/22WMR

Posted: Mon Jan 08, 2018 12:02 am
by Lundstrom9374
Hello everyone, I'm a new member here and looking to build a suppressor that will handle 22LR, 17HMR and 22 WMR.

I want to build it all out of Ti and have questions on design.

Looking at titaniumjoe.com, I would like to do it out of 1.125 OD .955 ID tube 6 inches long with a 1'' spacer and 5 60 degree cone baffles.

The tubing comes annealed or CWSR and I would like to use annealed so it's easier to cut the inside threads but don't know if I would loose to much strength?

So what do you guys think? I want the suppressor light and strong enough to last a life time. Thanks for any help.

Re: Forum 1 22LR/17HMR/22WMR

Posted: Mon Jan 08, 2018 7:30 am
by T-Rex
The annealed condition is almost twice as strong as 316SS. With walls as thick as .065 and a safety factor of 2, your WP is over 5kpsi.

Even for 17HMR and 22WMR, you'd benefit from more baffles. 6in of length should allow for much more than 5 cones and 1" of blast spacing might not yield a pleasant FRP.

Are you making all the parts yourself or relying on "solvent trap" pieces?

Re: Forum 1 22LR/17HMR/22WMR

Posted: Mon Jan 08, 2018 9:27 am
by ECCO Machine
That will be insanely heavy and wayyyyyy overbuilt. I don't even use .150 wall Ti on my full auto .30 cans. .070" wall, and thinned out toward the front down to .050"

Suppressors aren't firing chambers; they don't get hit with 60 KSI.

I build 3 ounce 7075 aluminum monocores with .023" wall gr. 9 Ti that handles .22 mag just fine.

If you want to do stacked baffles, look to the TBAC Takedown .22 design. It's rated up to 5.7x28mm, .22 Hornet, and I have it on good authority that the little can will actually handle the pressure of 5.56mm. I own one, and though a little on the heavy side at 5.9 oz., it's fantastic, one of the quietest.

Re: Forum 1 22LR/17HMR/22WMR

Posted: Mon Jan 08, 2018 9:55 am
by propeine
ECCO Machine wrote:That will be insanely heavy and wayyyyyy overbuilt. I don't even use .150 wall Ti on my full auto .30 cans. .070" wall, and thinned out toward the front down to .050"

Suppressors aren't firing chambers; they don't get hit with 60 KSI.

I build 3 ounce 7075 aluminum monocores with .023" wall gr. 9 Ti that handles .22 mag just fine.

If you want to do stacked baffles, look to the TBAC Takedown .22 design. It's rated up to 5.7x28mm, .22 Hornet, and I have it on good authority that the little can will actually handle the pressure of 5.56mm. I own one, and though a little on the heavy side at 5.9 oz., it's fantastic, one of the quietest.

The TBAC Takedown truly SHINES on a pistol in 22lr. On a rifle it sounded like anything else but on a pistol (where pressures are higher like 22mag) my ear said it was probably 5dB or more quieter than any other 22lr suppressor I've heard on a 4" barrel. Literally left me dumbfounded.

Re: Forum 1 22LR/17HMR/22WMR

Posted: Mon Jan 08, 2018 9:56 am
by Lundstrom9374
T-Rex wrote:The annealed condition is almost twice as strong as 316SS. With walls as thick as .065 and a safety factor of 2, your WP is over 5kpsi.

Even for 17HMR and 22WMR, you'd benefit from more baffles. 6in of length should allow for much more than 5 cones and 1" of blast spacing might not yield a pleasant FRP.

Are you making all the parts yourself or relying on "solvent trap" pieces?

I plan on making all of the pieces on my lathe. If I end up having problems cutting the hard Ti, I might have to buy some the pieces and use different metal for the cones.

What size blast spacing do you think I should do? I was thinking making the cones around 1'' long but if i make them shorter I can put more in. How many would be better them 5?

Thanks for your help.

Re: Forum 1 22LR/17HMR/22WMR

Posted: Mon Jan 08, 2018 10:08 am
by Lundstrom9374
ECCO Machine wrote:That will be insanely heavy and wayyyyyy overbuilt. I don't even use .150 wall Ti on my full auto .30 cans. .070" wall, and thinned out toward the front down to .050"

Suppressors aren't firing chambers; they don't get hit with 60 KSI.

I build 3 ounce 7075 aluminum monocores with .023" wall gr. 9 Ti that handles .22 mag just fine.

If you want to do stacked baffles, look to the TBAC Takedown .22 design. It's rated up to 5.7x28mm, .22 Hornet, and I have it on good authority that the little can will actually handle the pressure of 5.56mm. I own one, and though a little on the heavy side at 5.9 oz., it's fantastic, one of the quietest.
1.125 OD with .995 ID makes the walls .065 thick. I can get 1.125 OD with 1.025 witch would give a .050 wall. How much weight will the .015 of wall thickness add in a 6 inch tube?

I was thinking I could do the first cone in Ti then the rest in aluminum to save some weight.

I couldn't find any plans on the Thunder beast 22, if you have a link I will take a look.

Thanks for your help.

Re: Forum 1 22LR/17HMR/22WMR

Posted: Mon Jan 08, 2018 10:15 am
by ECCO Machine
Lundstrom9374 wrote:
T-Rex wrote:The annealed condition is almost twice as strong as 316SS. With walls as thick as .065 and a safety factor of 2, your WP is over 5kpsi.

Even for 17HMR and 22WMR, you'd benefit from more baffles. 6in of length should allow for much more than 5 cones and 1" of blast spacing might not yield a pleasant FRP.

Are you making all the parts yourself or relying on "solvent trap" pieces?

I plan on making all of the pieces on my lathe. If I end up having problems cutting the hard Ti, I might have to buy some the pieces and use different metal for the cones.

What size blast spacing do you think I should do? I was thinking making the cones around 1'' long but if i make them shorter I can put more in. How many would be better them 5?

Thanks for your help.
Ti cuts beautifully on lathes with sharp cutters/inserts. Single point threads nicely, too. Boring with twist drills and tapping are another story, though, as the material closes up on the tool.

The things to remember about Ti are:

1) it imparts nearly all of the heat on the cutting tool, versus other metals absobring it and the chips carrying heat away.

2) Ti chips can easily catch on fire, so be careful about letting them pile up.

As for design, your 6" length is good (my .22 cans range from 4.5"-7"), but I agree with Trex that you want more baffles. Small blast chamber and at least 8 baffles. The TBAC Takedown has 11.

Re: Forum 1 22LR/17HMR/22WMR

Posted: Mon Jan 08, 2018 10:20 am
by ECCO Machine
Lundstrom9374 wrote:
1.125 OD with .995 ID makes the walls .065 thick. I can get 1.125 OD with 1.025 witch would give a .050 wall. How much weight will the .015 of wall thickness add in a 6 inch tube?

I was thinking I could do the first cone in Ti then the rest in aluminum to save some weight.

I couldn't find any plans on the Thunder beast 22, if you have a link I will take a look.

Thanks for your help.
It's early, I read that as 1.25". Still don't need anywhere near .065" or .085" (1.125" OD .955" ID as in your OP is .085" wall). .020" to .025" wall is plenty for rimfire. Do make sure you're buying gr. 9, though (3Al2.5V). CP gr. 2 is barely stronger than aluminum. Tubing is not typically available in 6/4, though that's what you should use for baffles or cores.

Yes, aluminum will save considerable weight and is fine for rimfire and pistol cans, even full power rifle with limited firing rate. I built an 11 ounce can that I use on my .25-06, is all Al. except for a 6/4 Ti integral brake and the .028" wall Gr. 9 Ti sleeve. Al is 40% lighter than Ti (168 lbs vs. 284 lbs per cubic foot).

There are no available plans that I'm aware of, but lots of photos

Image

Re: Forum 1 22LR/17HMR/22WMR

Posted: Mon Jan 08, 2018 11:16 am
by T-Rex
The weight difference between the .065 and .05 wall tubings will be 22%.
For a 6" length, it will be a savings of ~.8oz

A 1/28 thread pitch, in .065, will give ~.04 material leftover in the root.
A 1/28 thread pitch, in .050, will give ~.025 material leftover in the root.

Even at .025, your tubing will have a WP over 2kpsi.

1/28 Pitch is plenty for this size design.

I'm guessing by ECCO's pic that there's barely any distance from muzzle to Blast Baffle tip and that the baffle spacing is around 3/8"
It appears 2 of the baffles have a symmetrical clip? Are these the primary baffles?

Re: Forum 1 22LR/17HMR/22WMR

Posted: Mon Jan 08, 2018 2:48 pm
by ECCO Machine
T-Rex wrote:The weight difference between the .065 and .05 wall tubings will be 22%.
For a 6" length, it will be a savings of ~.8oz

A 1/28 thread pitch, in .065, will give ~.04 material leftover in the root.
A 1/28 thread pitch, in .050, will give ~.025 material leftover in the root.

Even at .025, your tubing will have a WP over 2kpsi.

1/28 Pitch is plenty for this size design.

I'm guessing by ECCO's pic that there's barely any distance from muzzle to Blast Baffle tip and that the baffle spacing is around 3/8"
It appears 2 of the baffles have a symmetrical clip? Are these the primary baffles?
Yes, those are the first two.

As I mentioned, I use .070" wall gr. 9 Ti for 30 cals that I have beat the crap out of on my 13" .308 machine gun. They're threaded 24 pitch, which leaves .042" material. I got it hot enough that the .050" thick heat treated 8620 steel brake failed and deflected a bullet, sent it through all ten heat treated 17-4 stainless baffles and the end cap, but the tube was fine, and in fact I re-used it for the next baffle stack.

If you do use that heavier walled Ti, might as well thin it out in the middle to save weight. As Trex said, plenty of material for 28 pitch threads with rimfire pressures in .050" wall, and I'd personally take it down to .025" thick in the middle. .028" wall handles full power rifle cartridges just fine.

Re: Forum 1 22LR/17HMR/22WMR

Posted: Tue Jan 09, 2018 10:47 pm
by Lundstrom9374
T-Rex wrote:The weight difference between the .065 and .05 wall tubings will be 22%.
For a 6" length, it will be a savings of ~.8oz

A 1/28 thread pitch, in .065, will give ~.04 material leftover in the root.
A 1/28 thread pitch, in .050, will give ~.025 material leftover in the root.

Even at .025, your tubing will have a WP over 2kpsi.

1/28 Pitch is plenty for this size design.

I'm guessing by ECCO's pic that there's barely any distance from muzzle to Blast Baffle tip and that the baffle spacing is around 3/8"
It appears 2 of the baffles have a symmetrical clip? Are these the primary baffles?
Thanks for the info, this is great.

They also have it in .028, .035 and .040. How thin can i go and still have strong enough threads?

Re: Forum 1 22LR/17HMR/22WMR

Posted: Tue Jan 09, 2018 10:52 pm
by Lundstrom9374
ECCO Machine wrote:
T-Rex wrote:The weight difference between the .065 and .05 wall tubings will be 22%.
For a 6" length, it will be a savings of ~.8oz

A 1/28 thread pitch, in .065, will give ~.04 material leftover in the root.
A 1/28 thread pitch, in .050, will give ~.025 material leftover in the root.

Even at .025, your tubing will have a WP over 2kpsi.

1/28 Pitch is plenty for this size design.

I'm guessing by ECCO's pic that there's barely any distance from muzzle to Blast Baffle tip and that the baffle spacing is around 3/8"
It appears 2 of the baffles have a symmetrical clip? Are these the primary baffles?
Yes, those are the first two.

As I mentioned, I use .070" wall gr. 9 Ti for 30 cals that I have beat the crap out of on my 13" .308 machine gun. They're threaded 24 pitch, which leaves .042" material. I got it hot enough that the .050" thick heat treated 8620 steel brake failed and deflected a bullet, sent it through all ten heat treated 17-4 stainless baffles and the end cap, but the tube was fine, and in fact I re-used it for the next baffle stack.

If you do use that heavier walled Ti, might as well thin it out in the middle to save weight. As Trex said, plenty of material for 28 pitch threads with rimfire pressures in .050" wall, and I'd personally take it down to .025" thick in the middle. .028" wall handles full power rifle cartridges just fine.
I guess I was thinking way to beefy. I could thin out the center, I would have to pick up a longer boring bar with a insert. Thinking now I will go with .028 wall if it will still have enough strength at the treads.

Thanks for your help. I'm glad I asked the questions before buying the metal.

Re: Forum 1 22LR/17HMR/22WMR

Posted: Tue Jan 09, 2018 11:17 pm
by ECCO Machine
Lundstrom9374 wrote:
I guess I was thinking way to beefy. I could thin out the center, I would have to pick up a longer boring bar with a insert. Thinking now I will go with .028 wall if it will still have enough strength at the treads.

Thanks for your help. I'm glad I asked the questions before buying the metal.
Thin it on the outside. If you try to open up the bore, your baffles will be undersize to pass through the threaded section.

If you're going to thread the ends, you'll need to start with more than .028" wall, unless you're going to go with a really fine thread (40 pitch or finer). 28 pitch threads have a single depth of .023". When I'm using the really thin stuff, it's on my monocores, where the tube isn't threaded; it just slides over the core, seats on a shelf at the rear and is retained by a nut at the front.

I'd say use .050" wall tube, thread it 28 pitch, and thin the walls from the outside to .025" between the threaded sections (a subdued barbell shape, if you will). This I have done my welded stack rifle cans, with .070" wall threaded 24 pitch, and thinned in the center with a taper from .055" wall at the rear to .040" wall at the front.

Re: Forum 1 22LR/17HMR/22WMR

Posted: Sat Jan 13, 2018 2:46 am
by gunny50
17/4 would be my choose. Bit heavier but ultrasonic cleaning is great.
What's the wall on those 17/4 baffles? If you don't mind me asking.

Gunny

Re: Forum 1 22LR/17HMR/22WMR

Posted: Wed Jan 17, 2018 7:01 pm
by ECCO Machine
gunny50 wrote:17/4 would be my choose. Bit heavier but ultrasonic cleaning is great.
What's the wall on those 17/4 baffles? If you don't mind me asking.

Gunny
A lot heavier. Al is 168 lbs per cubic foot. Ti is 283 lbs per cubic foot. A cubic foot of stainless steel is 494 lbs.

I haven't measured the baffle thickness on the TBAC Takedown, but I've taken 17-4 baffles down to .025" thick in magnum centerfire rifle cans and .015" in pistol cans. Always thicker on the blast baffle, of course. 7075 Aluminum baffles I've run at .025" thick in pistol cans. I'm talking about the cone; I typically do not go thinner than .020" on walls. I just finished a 7-1/4" long pistol can prototype with eight 60° cone baffles that weighs 9.7 ounces with piston. The piston, piston housing and blast baffle are 17-4, the tube is .030" wall Ti and the other 7 baffles and end cap are 7075 aluminum.

And for the record, since it relates to this thread, I threaded the .030" wall Ti in 36 pitch (.018" single depth), and so far it's holding up with 9mm subs and standard 230 gr. .45 ACP. That said, if it were a personal form 1 can and not a prototype as an SOT where a failure means I'm just out my time and a little bit in materials, I'd have gone thicker

Re: Forum 1 22LR/17HMR/22WMR

Posted: Thu Jan 18, 2018 11:44 am
by gunny50
ECCO Machine"

A lot heavier. Al is 168 lbs per cubic foot. Ti is 283 lbs per cubic foot. A cubic foot of stainless steel is 494 lbs.

Sure its heavier but the walls can be thinner in 17/4 900 than in Ti or Allu.

So in the end not that crazy much more and you can dip, beat blast or ultrasoon clean them. Ti and Allu are not that forgiving.
And that can could be used for 22-22wmr-22Hornet - 5.7 and maybe even 4.6.
But its just what you want or need.

PS your right. its great to be able to experiment. :wink:
Gunny

Re: Forum 1 22LR/17HMR/22WMR

Posted: Thu Jan 18, 2018 8:31 pm
by fishman
The strength to weight ratios on 17-4, grade 5 ti, and 7075 are all really close.

Re: Forum 1 22LR/17HMR/22WMR

Posted: Fri Jan 19, 2018 11:47 am
by ECCO Machine
gunny50 wrote:
Sure its heavier but the walls can be thinner in 17/4 900 than in Ti or Allu.

So in the end not that crazy much more and you can dip, beat blast or ultrasoon clean them. Ti and Allu are not that forgiving.
And that can could be used for 22-22wmr-22Hornet - 5.7 and maybe even 4.6.
But its just what you want or need.

PS your right. its great to be able to experiment. :wink:
Gunny
The walls can only be so thin, regardless of material. They still have to be able to slip into the tube and stack together positively, which is gonna be sketchy with < .020" or so skirts on the baffles.

The strength to weight ratio of Ti is higher than 17-4, too. 128 KSI vs 150 KSI yield strength in annealed states. 7075-T651 aluminum is 73 KSI. If we put that into ratios with weight, you get a better idea. The following numbers are useless other than comparing strength to weight, but if we take the yield strength and divide by the weight of 1 cubic foot of material:

6/4 Ti: 448
7075-T651: 434
17-4 H1150: 304

This shows that Ti has a strength-to-weight ratio almost 50% greater than 17-4 H1150. It's a smaller gap with solution treated and aged 6/4 vs. 17-4 H950, but still significant. As you can also see, 7000 series aluminums have an impressive strength to weight ratio, and excellent hardness when anodized (North of 60 Rc), but the low melting point of aluminum will always be a factor in suppressors. For rimfire and pistol rounds, though, it's really a non-issue. Al also dissipates heat much faster; while my ultralight 7075 monocore rifle cans with thin Ti sleeves heat up fast and are not designed for heavy fire, they also cool much more rapidly than suppressors made with Ti, stainless or Inconel baffles/cores.

Bottom line, no other metal beats Ti in the strength to weight ratio. It also has the highest melting point of the three being discussed here. There are physical properties of the material that make it unsuitable in some applications, namely it's lack of hardness and tendency to gall. But for suppressor baffles, the lower hardness vs. treated 17-4 is offset by the higher melting point.

I say stick with Ti for the housing, use hardenable steel for the threads in the base for longevity with ostensibly constant installation and removal, but otherwise it's gonna be impossible to beat aluminum for weight, it's plenty strong, and will clean easy enough, especially if you hard coat anodize. Or use Ti for the baffles as well, if you don't mind the cost. You can make them very thin in a rimfire.

Re: Forum 1 22LR/17HMR/22WMR

Posted: Fri Jan 19, 2018 12:16 pm
by T-Rex
I wouldn't consider melting point a property to include, when dealing with anything other than Al. Both Ti and 17-4 will have lost >50% of their strength at 1000F; well before either of their MP's. What I believe to be more important than strength to weight, would be lost strength % at a reasonable temp, say 600F. This is well w/in the operational temp's of a centerfire device. I know the thread started as 22lr but wth :lol: . At this 600F, H900 is >40% and H1150 is >20% stronger than Ti. This is greater than at room temp. Also, if you were to use H900 for your strength to weight factor, it would be much closer to the pack than H1150.

Anyway, all 3 of these materials are capable of withstanding the forces applied to a suppressor, w/in their own respective limits. Plenty of totally Al cans are sold for magnum centerfire, outside the US.

Re: Forum 1 22LR/17HMR/22WMR

Posted: Fri Jan 19, 2018 12:42 pm
by Enfield577
"Plenty of totally Al cans are sold for magnum centerfire, outside the US."

And they work without issue.

Re: Forum 1 22LR/17HMR/22WMR

Posted: Sun Jan 21, 2018 9:09 pm
by fishman
Titanium has a high melting point, but if you heat it above 800° it starts to absorb oxygen and becomes brittle and weak. This is why welding it requires so much shielding gas.

Re: Forum 1 22LR/17HMR/22WMR

Posted: Mon Jan 22, 2018 4:00 am
by Hannibalbarca
You can get away with a smaller blast chamber, half inch or .75 inches. I’d also make the first two baffles, or all of them, from 17-4 stainless and you can get way more than 5, 10 or even a couple more.

Re: Forum 1 22LR/17HMR/22WMR

Posted: Thu Jan 25, 2018 9:31 am
by ECCO Machine
T-Rex wrote:I wouldn't consider melting point a property to include, when dealing with anything other than Al.
Since flame erosion is a component of suppressor baffle wear, I don't think it should be ignored. Ti also has better thermal conductivity, so cools a little faster and, though I am not sure how it translates to direct flame exposure, but Ti resists heating much more than steel in machining, which is why it's so hard on tooling.

If it weren't for weight (and cost), I'd be using tungsten for blast baffles.
T-Rex wrote: Also, if you were to use H900 for your strength to weight factor, it would be much closer to the pack than H1150.
Yes, but I chose annealed physical properties for simplicity, and because many builders are not treating the materials. 6/4 Ti and 17-4 stainless have the most impressive properties in annealed states of common alloys.