45 Cal Suppressor Design Review

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Re: 45 Cal Suppressor Design Review

Post by ECCO Machine » Thu Jan 03, 2019 1:03 pm

T-Rex wrote: As far as drilling the coaxial sleeve's outer holes on an angle to impart spin on the gases: not going to happen. There's not enough wall thickness to create a directional channel.
I didn't see any dimensions, though scale suggests about 1/16" wall tube. I have never executed a coaxial like that, but I can tell you from looking at carbon fouling patterns that the .090 walls of my muzzle breaks are thick enough to direct the gasses with 3/16" holes bored in the manner I recommended.

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How much of the gas is directed I couldn't say, but enough to show a distinct pattern after a few rounds. I have never photographed what I've seen on the blast baffle and in the chamber with these, but I'll make a point of it next time I have a fresh can. Or maybe I'll tear down Phantom and clean the blast baffle, since that's a serviceable can. The pattern is evident for a time, but not really visible once everything is thoroughly coated in carbon.

OP has CNC capability, so no reason he couldn't start with thicker tube and machine hemisherical scoops around the rear of each port. This brake I made a few years ago is along those lines, and it
directed the gasses enough to blow my hat off:

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Other ways to generate a vortex, of course. This was a prototype I did for a .22 can. It had no coaxial chamber, I was seeing how it would help with FRP.

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But a blast baffle of this type could be used at the rear of the OP's stack. That's how I did Vorticis

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I'm doing all this on manual equipment, of course. OP could make more intricate designs.
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Re: 45 Cal Suppressor Design Review

Post by John A. » Thu Jan 03, 2019 1:13 pm

I like how you did that. I would expect that would have worked really well.
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Re: 45 Cal Suppressor Design Review

Post by T-Rex » Thu Jan 03, 2019 2:21 pm

ECCO Machine wrote:I can tell you from looking at carbon fouling patterns
I understand where you're going and you're correct that the fouling patterns will differ from a 90* hole to a 45*. However, I believe this would be from the gasses reaching one low pressure side before the other, instead of a true directional change. With the same wall thickness, more holes w/ a smaller diameter would create a greater impact. Like what Q did w/ the Cherry Bomb. Also, the angled groove helps as w/ your brake design. The larger holes may empty the chamber quicker, but that's not what we're discussing.

These are a great concept:

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However, the lack of a constant flow hinders a favorable vortex. They will help impart spin, though.
We use the inverse for some refractory designs, to help w/ additional combustion air swirling.

I do like this design.

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ETA: Here's a picture of what a truly controlled directional change looks like

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Last edited by T-Rex on Thu Jan 03, 2019 2:31 pm, edited 1 time in total.
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Re: 45 Cal Suppressor Design Review

Post by fishman » Thu Jan 03, 2019 2:26 pm

When OP decides not to do an integral:

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In all seriousness, the design looks good. I agree with all the above recommendations. Put some more snout on those radials.
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Re: 45 Cal Suppressor Design Review

Post by Colo32 » Thu Jan 03, 2019 9:52 pm

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Re: 45 Cal Suppressor Design Review

Post by Colo32 » Thu Jan 03, 2019 9:56 pm

fishman wrote:When OP decides not to do an integral:

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In all seriousness, the design looks good. I agree with all the above recommendations. Put some more snout on those radials.
Integral is still on the table!

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Re: 45 Cal Suppressor Design Review

Post by T-Rex » Thu Jan 03, 2019 10:38 pm

I think you have too many baffles. Keep it under a dozen. At some point the pressure will diminish and the baffle faces will be less efficient. You want a bit more room between baffles. Same goes for the vanes on the exterior of the baffles. With that regard, I think the alternating vanes will be more affective. They should also provide more surface area to strip and transfer heat.

While you're at it, why not design a 3-lug which incorporates a muzzle brake. This would aid in filling the coaxial volume. Maybe perforating the blast chamber's spacer tube, a bit more, also.

I would think about slimming down the exit cap. I prefer no shoulder to seat on. The interior profile isn't needed. A tunnel can sometimes create an unwanted tone. This would be a great place to incorporate a neoprene wipe. Very simple to do and could be used or not, but function wouldn't suffer , either way.
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Re: 45 Cal Suppressor Design Review

Post by fishman » Thu Jan 03, 2019 11:56 pm

T-Rex wrote:The interior profile isn't needed. A tunnel can sometimes create an unwanted tone.
The 556 can I made has a profiled front cap. Without the baffles installed, when blowing through the can, it would make a low pitched whistle. Very amusing
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Re: 45 Cal Suppressor Design Review

Post by ECCO Machine » Fri Jan 04, 2019 9:36 am

Having CNC makes doing those vanes more feasible, and they'll locate the baffles radially without the need for an inner tube. It'll also help with conduction. But I wouldn't make a solid helix or zig-zag with them, just gobbles up internal volume and introduces more resistance getting the gasses into the coaxial chamber. I would do the first three, leave the rest smooth. Or, reduce the number of vanes by about 2/3 to where there's only 6 or 8 per baffle, and have them offset equally from one baffle to the next.

The other changes I'd make are:

1) The first baffle would be a 40° included straight wall cone, spaced about 3/4" off the muzzle

2) Reduce the ID of the baffles a little to where your coaxial is 1/8" tall

3) Instead of a ported spacer that the gasses have to fight their way through to make use of the coaxial, use a spacer that is thin and tight to the outer tube. The helix vanes can space your stack off of that. Bring the vanes on the blast baffle back over the cone a little to make more room for gasses to escape into the coaxial between cone wall and spacer.
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Re: 45 Cal Suppressor Design Review

Post by Colo32 » Sat Jan 05, 2019 12:57 am

I made many of the recommended changes:
Fewer baffles
Increased spacing of baffles
Added 40* included angle blast cone with radial fins
Removed radial fins on all but 4 radials (3 in front & one mid support)
Reduced fin count to 8
Increased radial space between radial baffle OD (base of fins) and outer tubes to .125"
Put both endcaps on a diet
increased gap from muzzle to blast baffle from .500" to .75"
Increased inner tube dia. in blast area to fit ID of outer tube, & removed holes


I am working out a possible 3-lug adapter/muzzle brake design
Do I need a mousehole in the blast baffle?
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Re: 45 Cal Suppressor Design Review

Post by fishman » Sat Jan 05, 2019 11:15 am

Colo32 wrote:Do I need a mousehole in the blast baffle?
Some people do, some people don't. I've never tested it myself but I'd imagine that poi shift will be increased significantly by clipping the blast baffle.
There's still room for thinning out the front cap. The weight out at the front is where it feels the heaviest.

It looks like a solid design
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Re: 45 Cal Suppressor Design Review

Post by T-Rex » Sat Jan 05, 2019 12:03 pm

fishman wrote:I've never tested it myself but I'd imagine that poi shift will be increased significantly by clipping the blast baffle.
I'm not sure if he's asking about a clip or a true mouse hole. I'd agree that the clip should be ignored, only since testing isn't allowed.
If it were a higher pressure design, I'd think the mouse hole (porting) could help. However, this being a coaxial design, for lower pressure rounds, I'd ignore this feature.

fishman wrote:There's still room for thinning out the front cap.
I agree.
I also think the rear portion can be revised. I see no reason for the stepped tubing and keeping the mount larger than it needs to be. There's plenty of room to make the tube uninterrupted. This will remove additional, unnecessary, weight.


If you do add a muzzle brake feature to the mount, I'd move the blast baffle closer to the muzzle.
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Re: 45 Cal Suppressor Design Review

Post by garredondojr » Sat Jan 05, 2019 2:16 pm

some very cool designs. on the last design I would think it would work better if you went back to the spacer that sealed the vanes on the blast baffle then have that spacer ported in an angled helix pattern like ECCO's muzzle brake shown a few posts up. otherwise your blast chamber volume would be massive and I would think FRP would be an issue. but I really don't have the expertise to validate my assumption.

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Re: 45 Cal Suppressor Design Review

Post by ECCO Machine » Sat Jan 05, 2019 8:24 pm

I think that looks like a winner.

I also think if you make it from appropriate materials that it would perform favorably on rifles. With the apparent thickness of the parts, if it's made from Ti or 17-4 SS, that should handle most anything. That said, it wouldn't hurt to have a little more thread on both ends if you think you might ever hit it with rifle rounds.
garredondojr wrote:some very cool designs. on the last design I would think it would work better if you went back to the spacer that sealed the vanes on the blast baffle then have that spacer ported in an angled helix pattern like ECCO's muzzle brake shown a few posts up. otherwise your blast chamber volume would be massive and I would think FRP would be an issue. but I really don't have the expertise to validate my assumption.
FRP seems to be more impacted by distance from muzzle to blast baffle than size of blast or coaxial chamber. You want to keep it as close as possible, while still giving enough room for the features of the blast baffle & chamber to do their job. That's why I suggested ~3/4" spacing, so there will be enough time for much of the high pressure gas to find it's way up the sides of the blast baffle, through the helix and into the coaxial chamber before the path through the aperture is the one of least resistance. The beauty of using a helixed vane system is that in addition to the benefits of promoting flow in one direction, it inhibits it in another; the gasses that escape into the coaxial have to fight their way back out past vanes facing the wrong direction even after blast chamber pressure is lower than it is in the coaxial. That means a slower bleed back and less noise.

The brake I have works very well for high pressure rifle rounds, but I don't think it would do much for .45 ACP.
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Re: 45 Cal Suppressor Design Review

Post by Colo32 » Sat Jan 05, 2019 9:04 pm

I will make another pass at lightning the front cap, i have just the fix for it. The outer tube is 1.75 OD .070 wall. The outside profile is just something I tried to see what it looks like.
I have .325" of engagement on the endcap threads. I prefer to have more than not enough. I'm actually going to increase the thread diameter on the front cap to match the rear.
I do have a 450 Bushmaster I may try this can on, but I bought the Hybrid 46 for it.
As far as materials, grade 9 Ti tubes, grade 5 Ti baffles, 17-4 blast cone, 7075 front cap. Im working on various brake ideas for the rear, so material there TBD.
I have spent hours on YouTube watching slow motion videos of brakes. I found this one interesting https://youtu.be/pADNHyt_atE. The first one shown I like. I'm working on one with a thicker wall and a BUNCH of offset, forward angled holes.
Am I correct in assuming I can make and test as many brakes as I want since its not a supressor part? I have built many different brakes in the past, just none that serve as a mount.

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Re: 45 Cal Suppressor Design Review

Post by John A. » Sat Jan 05, 2019 11:17 pm

You can make as many brakes as you want.

The most effective brake I have ever used has been the JP Enterprise recoil eliminator.

If you're doing an over the barrel/reflex can, I suggest making something that ports very rearward.
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Re: 45 Cal Suppressor Design Review

Post by ECCO Machine » Sun Jan 06, 2019 2:07 am

Colo32 wrote: As far as materials, grade 9 Ti tubes, grade 5 Ti baffles, 17-4 blast cone, 7075 front cap. .
Not much of a weight penalty to go SS or Ti with the front cap, much strength gained. The only cans I run 7075 or 7068 for the front cap are rimfires and my Phoenix IX. All the rest are 17-4 H900, 440C with a 550° temper, or gr. 5 Ti.
John A. wrote: If you're doing an over the barrel/reflex can, I suggest making something that ports very rearward.


But we're trying to force gas into a forward coaxial chamber, so rearward ports would be counterproductive.

I think the design is solid as is, save for giving more thread engagement. The mount design he has can be left solid for pistol calibers, getting them closer to the blast baffle and giving him the freedom to adjust spacing there with new, unregulated mounts. If he decides to run it on rifles, he can do short muzzle brakes with the same profile.

One thing I don't see in the CAD drawing is a taper behind the threads on the mount, looks like a square shoulder. A taper will help with both repeatability and retention. A taper between 10° and 20° included angle would be a good idea. I run a 12° included taper with 1"-12 TPI threads on the brakes pictured above. The can threads on in 4 revolutions and stays tight on full auto rifles.
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Re: 45 Cal Suppressor Design Review

Post by T-Rex » Sun Jan 06, 2019 9:39 am

ECCO Machine wrote: But we're trying to force gas into a forward coaxial chamber, so rearward ports would be counterproductive.
Indeed
A taper will help with both repeatability and retention.
I thought we were using a 3-lug mount?
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Re: 45 Cal Suppressor Design Review

Post by Colo32 » Sun Jan 06, 2019 6:54 pm

Latest revision with:
Thinned front cap
Revised rear cap to allow for various adapters
Adapter for muzzle brake
Muzzle brake

I really like the idea of a brake
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Re: 45 Cal Suppressor Design Review

Post by T-Rex » Sun Jan 06, 2019 8:47 pm

Looking good.
Personally, I'd make 3 revisions:
-Reduce the length of the muzzle brake, maybe to 1"
-Reduce the spacer on the blast baffle by half.
-Increase baffle spacing to approx 9/16 (.550 works almost perfect with the changes above)

My reasoning is that the blast chamber isn't doing nearly as much as the coaxial and baffle areas. A 1" brake, coupled w/ the spacing to the blast baffle and the cones length, should give enough volume. Get that gas into the coaxial area and have plenty of it. Also, each baffle spacing/volume will be more efficient than that of the blast chamber.

My fourth alteration would be to give every baffle the fins. They're thin enough that they shouldn't be an appreciable amount of weight or stealing from volume. The added material will work the gases and aid with heat dissipation. Run the numbers on weight and volume affect. The cnc makes it an easy enough call, based on effort.


Next is the clip deign.
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Re: 45 Cal Suppressor Design Review

Post by fishman » Mon Jan 07, 2019 12:53 am

The baffle clip looks like you did a plunge cut all the way through when it should really be a endmill run sideways through the baffle.

I still think the baffle profile could use some tweaking too

That 60 taper on the brake should be more like 10-15 degrees. Why does the brake have two tapers?

The brake is probably hurting more than its helping, you'll get better expansion into the blast chamber and coaxial area without that brake in the way. Id do a short single port brake or no brake at all. Unless you want the brake for shooting unsuppressed, its not going to do you any good.
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Re: 45 Cal Suppressor Design Review

Post by ECCO Machine » Mon Jan 07, 2019 11:27 am

fishman wrote:The baffle clip looks like you did a plunge cut all the way through when it should really be a endmill run sideways through the baffle.
Yup.

I run the clip perpendicular to the side of the cone.

Also agree on making the taper on the brake a lot more acute. I don't know what thread pitch you'll be using, but with 12 TPI, even a 20° included was too obtuse for a good lock. That's why I went to 12° Included.
T-Rex wrote:Looking good.
Personally, I'd make 3 revisions:
-Reduce the length of the muzzle brake, maybe to 1"
-Reduce the spacer on the blast baffle by half.
-Increase baffle spacing to approx 9/16 (.550 works almost perfect with the changes above)

My reasoning is that the blast chamber isn't doing nearly as much as the coaxial and baffle areas. A 1" brake, coupled w/ the spacing to the blast baffle and the cones length, should give enough volume. Get that gas into the coaxial area and have plenty of it. Also, each baffle spacing/volume will be more efficient than that of the blast chamber.
As an unregulated part, he can keep trying different brakes to adjust number, type & orientation of ports, and distance to blast baffle. As heavily ported as the model shows, I think it will work fairly well even with very little spacing to the blast baffle. He can also make different brake adapters, since his rear mount is yet another piece, playing with length and volume of blast chamber. But he can't make it any longer without a new stamp.

I would probably ditch the second taper, though. Trying to make both of those surfaces useful is gonna require some ridiculous tolerances. I understand the thought process behind it, but a single, larger diameter taper behind the threads works fine, is employed by many manufacturers.

T-Rex wrote:My fourth alteration would be to give every baffle the fins. They're thin enough that they shouldn't be an appreciable amount of weight or stealing from volume. The added material will work the gases and aid with heat dissipation. Run the numbers on weight and volume affect. The cnc makes it an easy enough call, based on effort.
I'll respectfully disagree here. With vanes running all the way up, you'd have pretty much the same effect as no vanes, with gas going straight into them and then trying to come straight back out. With only the first few bearing the helix, the gasses will be spinning around the core. Once they make it to the end, they want to come back out, but to do so, they have to get past the vanes that are more like walls for a vortex with the same rotation but opposite flow vector. That volume will be forced to stay in the coaxial chamber until everything has settled down enough in and out of the chamber for them to bleed out.

I don't have a professional resume involving fluid dynamics, but I do have an intuitive understanding of it, and have employed some form of helix in many of my designs with some very good results. And it's been more than a handful of cans & stacks with the luxury of being able to create at will under my 07/02 and then file a F2 once it's something worth keeping around for further development.
T-Rex wrote: Next is the clip deign.
You're not a fan of the radiused assymetric? I'd run with it.
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Re: 45 Cal Suppressor Design Review

Post by T-Rex » Mon Jan 07, 2019 11:57 am

ECCO Machine wrote: As an unregulated part, he can keep trying different brakes to adjust number,
Yes, but a shorter brake isn't going to change the blast chamber length. While you could play with the brake, the baffles are untouchable. I think the shorter brake will give plenty of dispersion and he'd only benefit from a longer baffle and coaxial length.

With vanes running all the way up, you'd have pretty much the same effect as no vanes,
I agree, if the vanes oriented to create a channel. I'd either make a zigzag design or make them all identical, so they didn't line up. The vanes would essentially cut the gas at every baffle.

You're not a fan of the radiused assymetric? I'd run with it.
I'm w/ what you and Fishman were describing. I just didn't get too involved and left it at a blanket design review. I can agree that the asymetric works good, both on the radial baffles and low pressure designs
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Re: 45 Cal Suppressor Design Review

Post by Capt. Link. » Mon Jan 07, 2019 1:10 pm

I know we are throwing allot at you but you can add tune-ability to the design.If you internally thread the tube and externally the baffles you can then change the spacing and the blast chamber volume.This has been done at least since the 1960's and is within all laws regarding a F1 build.This will lighten the suppressor ,eliminate spacers plus increase surface area and heat dissipation. When thinning the front cap remember it sees little pressure so a .050 thick cap is plenty for all but the big boomers.
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Re: 45 Cal Suppressor Design Review

Post by fishman » Mon Jan 07, 2019 1:28 pm

I know we are throwing allot at you but you can add tune-ability to the design.If you internally thread the tube and externally the baffles you can then change the spacing and the blast chamber volume
That'll be fun once carbon gums up the threads. That's a hard pass from me.
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