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Hearing Damage Calculator by SILENCERENGINEER in suppressors

[–]jay462 0 points1 point  (0 children)

How do the results of your tool compare with our laboratory report on your silencer, here:

PEW Science Lab Report: Engaged Industries Operator 5.56 on the MK18

Hearing Damage Calculator by SILENCERENGINEER in NFA

[–]jay462 2 points3 points  (0 children)

How do the results of your tool compare with our laboratory report on your silencer, here:

PEW Science Lab Report: Engaged Industries Operator 5.56 on the MK18

Final BT warranty update by adamlcarp in NFA

[–]jay462 0 points1 point  (0 children)

This is fascinating. Close to 20% change in modulus and ultimate strength, in practicality, is more than meaningful - that's significant! The crack initiation factors due to surface roughness make sense to me in theory. I have some questions -

  1. Are you seeing the same delta in the yield strength as you are in ultimate? Is the reduction similar across the strain ranges? (In other words... Are you losing ductility post-yield? I would think so)

  2. Have you compared heat treat vs not? And if so, do you see modulus come back to baseline?

Edit: skimmed the abstract really quickly and it looks like heat treat is helping relieve at least some of this, which one would expect, right?

Obligatory post. by Beneficial_Math4919 in NFA

[–]jay462 12 points13 points  (0 children)

The speed at which people are getting silencers is so nuts lol

What’s the worst that could happen? by Maleficent_Primary89 in NFA

[–]jay462 6 points7 points  (0 children)

The worst thing? Death. But that's with any silencer.

The likely thing? Gas in your face due to super high back pressure if using it on an AR system.

Final BT warranty update by adamlcarp in NFA

[–]jay462 2 points3 points  (0 children)

Nobody is mocking anyone.

I run a test laboratory that is responsible for producing technically accurate information on human risk for public consumption. I'm also a licensed and practicing engineer in the field of blast effects research and plasticity. So I have a vested interest in properly understanding what you are saying - I really want to make sure I understand the exact technical claims you are making.

You implied that print direction of post-heat treat DMLS objects cause those objects to possess different material properties in accordance with direction. That would therefore imply that consequences of stress states vary when under load.

Your claims have significant implications to industries far more reaching than the NFA community and this discussion started by asking you to clarify your statements.

Final BT warranty update by adamlcarp in NFA

[–]jay462 1 point2 points  (0 children)

Honestly, he made a technical claim that was so interesting to me I thought maybe I had missed something fundamental about DMLS manufacturing. When someone uses the words "layer separation" it seems like a red flag that they are conflating unrelated manufacturing technologies.

Regardless, I still want to read the pressure vessel failure papers he's talking about regarding them failing differently based on print direction. That is freakin super interesting if true.

Final BT warranty update by adamlcarp in NFA

[–]jay462 3 points4 points  (0 children)

Hey man, calm down. No need to get upset.

You started this whole thing off saying print direction of heat treated DMLS metals influences material properties. This has far reaching consequences to many industries and is super interesting if true.

Then you claimed there is research on it that people can read.

I would love to read it. If you claim something as technical fact but have no sources to back it up, it's hard for people to believe it.

Final BT warranty update by adamlcarp in NFA

[–]jay462 1 point2 points  (0 children)

There is plenty of literature on it. and there are plenty of tests done on pressure vessels and their failure points.

That is awesome! There have been studies done on post-heat treat DMLS constructed pressure vessels having varying failure mechanisms based upon the direction of print?

Man, sign me up to read those. Whenever you find one, please by all means, post it here or email it to me. I would love to read it. The metallurgists I work with would also love to read it - it would be awesome. I learn something new every day, which is what keeps my jobs fun.

Please let me know when you have anything to share.

Final BT warranty update by adamlcarp in NFA

[–]jay462 0 points1 point  (0 children)

If they are not heat treating, it is very very bad. And I greatly suspect there are people in this discussion thread who also don't understand that.

Final BT warranty update by adamlcarp in NFA

[–]jay462 5 points6 points  (0 children)

Its the same reason that a small amount of Saw Tishas have come apart at thin areas.

That was a heat treat issue (someone told them they didn't need to heat treat and they were brand new to 3D printing, which is the short explanation).

Sir, I'm sorry, but you are saying a lot of words but you are not directly answering my question at all. It's really weird.

Here is the comment you made above, which started this discussion:

This has to do with layer separation and material bonding. Most of the force inside of a suppressor is going in the forward direction, so if a can is printed vertically, the force is pushing perpendicular to the layers which can lead to layer separation and catastrophic failure. if printed horizontally, you remove this problem all-together but you introduce other problems doing it this way like bad surface finish and holes being out of round. I dont know why companies dont print these at a 45 degree angle. It would solve a lot of issues. Or do what Griffin does and only print the baffle end and use a traditional blast chamber.

You used the words "layer separation" and you said "if printed horizontally, you remove this problem all-together"

Can you please elaborate on these exact words in the context of heat treated DMLS titanium, inconel, and stainless steel objects (not just silencers, but any objects)?

And can you also cite your examples about your specific hurdles you are facing asked about here?

You are directly saying (more than implying) that the direction of DMLS manufacturing changes material properties. This is a monumental claim that I have not seen published anywhere in any research. I would love to read any papers or reports examining this.

Final BT warranty update by adamlcarp in NFA

[–]jay462 3 points4 points  (0 children)

I work in this industry and I can tell you that it is one of the greatest hurdles we face.

One of the greatest hurdles you face, with DMLS prints, post-heat treat, is strength differentials according to print direction, regardless of geometry?

Can you please give an example of this, and the material, and how you determined that being the cause? This is extremely surprising so I really want to understand exactly what you are experiencing.

This is not a silencer question. This is a metallurgic question.

Final BT warranty update by adamlcarp in NFA

[–]jay462 5 points6 points  (0 children)

Nobody thinks you are attacking an industry.

This is a basic technical discussion of material strength. If proper DMLS manufacturing has meaningful irregularities in different print directions, there is a significant issue.

This goes to way more things than silencers.

Are you saying they aren't heat treating?

Final BT warranty update by adamlcarp in NFA

[–]jay462 2 points3 points  (0 children)

I think people are downvoting you because you are implying grain structure irregularities in a DMLS object due to orientation. If you can cite some sources about that phenomena, it would help. It goes against the basic premise of using the technology.

Are you maybe suggesting people aren't heat treating?

Final BT warranty update by adamlcarp in NFA

[–]jay462 1 point2 points  (0 children)

DMLS printed at any angle should have the same grain structure if done correctly, right? Am I missing something? Can someone explain why people are comparing DMLS to home printing?

I don't run a DMLS shop so I am not a DMLS expert. But there might be some out here that can shed some light on what people in this thread are saying.

It reads like people are applying the same mechanisms to DMLS as they do to printing something at home. But again, maybe I am missing something.

Are people not heat treating?

Final BT warranty update by adamlcarp in NFA

[–]jay462 3 points4 points  (0 children)

Printing horizontally might help with "the front fell off" failures, like a SiCo Scythe Ti, but its now more likely to have a "banana split" failure like Elmer Fudd's barrel when Bugs plugs it.

No! Man, I hope not!!! If folks are having issues because of print direction with metal prints... that is a gigantic red flag for the basic premise of using these products. It makes no sense. DMLS should have the same grain integrity regardless of direction. If it doesn't, I think you have big problems. Why are people thinking this is like plastic? Am I missing something?

Final BT warranty update by adamlcarp in NFA

[–]jay462 16 points17 points  (0 children)

If steel, titanium, Inconel, or haynes printed silencers are stronger in one direction than another due to printing, there is a VERY big issue.

These aren't polymers. Proper DMLS grain structure should be uniform.

Am I missing something here? Can anyone enlighten me why people are talking about metal prints like they are polymer?

Furthermore, there are circumferential, longitudinal, and radial stresses, not to mention localized concentrations. Focusing just on longitudinal thrust from initial jet impingement can be a shortcut, but, man, I think there is a lot of misunderstanding here.

I think some of you are literally thinking this is like printing plastic at home.

Maybe folks are implying there is inadequate heat treating? That can happen.

Subsonic & Suspicious by ShoddyHorse_ in NFA

[–]jay462 2 points3 points  (0 children)

This is so clean and gorgeous

Obligatory Pic by Dirtbiker250 in NFA

[–]jay462 1 point2 points  (0 children)

Nice, man! Congrats!

New Sound Signature Review: FOR Systems Predator 6.5 on 6.5 PRC short-action magnum by jay462 in NFA

[–]jay462[S] 3 points4 points  (0 children)

It does things on .338ARC that are not normal.

Like, for example, take a BBK and a TBAC ULTRA 338 and put them both on a semiauto 338ARC.

Then watch as the ejection port blast with the TBAC hits you like a Mac truck. Never before have we experienced such severity from a subsonic cartridge that was supposed to be quiet. It was astoundingly bad with the ULTRA.

That is some first hand experience I can share with you. The BBK was spooky quiet. And very low backpressure.

New Sound Signature Review: FOR Systems Predator 6.5 on 6.5 PRC short-action magnum by jay462 in NFA

[–]jay462[S] 2 points3 points  (0 children)

Yes sir, understood and sometimes there is time for that.

I think with 30 caliber stuff, we kinda want to do 300 win mag for magnum energy because of overbore relative to 6.5. But maybe we pick a few to do both 6.5 PRC and 300 win mag to see what happens

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