Stainless steel

[Imadaddyof7]

Hello all,
First off let me say, I am not a big forums guy and rarely have the need to ask questions. As far as a form 1 goes however I am in need of some metalurgy advise. My background consist of 30 years as a multi axis cnc machinist. My form1 will be using a 1.562 o.d. .065 wall titanium grade 5 tube 7inches long. The first spacer and blast baffle should be made from 17-4 stainless, however I have access to XD15 stainless will this be better or worse in comparison?

[Capt. Link.]

I would ask a bunch of questions and do extensive research in our archives. Giving us as much information as possible helps with getting quality information. Caliber choice and barrel length are basic information needed.Subsonic or supersonic,full auto fire or slow fire plus host weapon also are helpful.
With this basic information a baffle type and general spacing can be suggested.This also will help to determine if a blast chamber and baffles need to be of special materials.
I will reserve any comment about the listed components until I know more about the build.
Welcome Aboard
-CL

[Imadaddyof7]

I have done extension research on material with little to no resolution for XD15 as. As stated previously not a big forums guy but will indulge. Multi- Cal suppressor similar to silenceco hybrid 46, but without a welded stack 60 degree clipped cones with spacers with the first blast chamber being 1.35 to far side of 60degee. The form 1 is 9mm. 7inch long titanium grade 5 1 9/16 od. Round stock bored to .065 wall. First 60 degree cone to be XD15 ss???(question). At .06 wall od and Id taper. Then 6-7 addition cones( prolly titanium grade 9) with less space between to be determined as it goes for on the fly machining. I think that is enough info. So basically proven design, just not sure how XD15 can fit in this mix at all? Mainly because that is what I have the most access too. So this will be used primarily on nak9 11.5 barrel and also on ar15 16" barrel and also ar10 16" barrel.

[Imadaddyof7]

Also, what do I need to do to be able to post my sketch?

[#40Fan]

imgbb.com and upload your sketch there. Post the BBCode Full Linked.

[Imadaddyof7]

https://ibb.co/9YdnKXV

Rough sketch with radius baffles or could make cones what would be best for the multi Cal.

[T-Rex]

I had to look the X15 up, but unless you can guarantee a full heat treat (quite extensive cycle for this metal), 17-4 will be stronger. Also, from what I read, 17-4 looks to be easier to machine, if that's a prerequisite. Are you getting the X15 for free? If not, I can almost guarantee that 17-4 will be cheaper. That being said, if the price is right, machining isn't an issue, and you are able to properly HT, it looks like a comparable metal.

Personally, I'd stick w/ clipped 60deg cones, especially for a multi-purpose build. At least until you get a better understanding of what's required, per application.

Decrease your second spacer, from 1 to .75, and increase your last 2.

I will say, however you have a lot of unnecessary material/weight. With the materials you've chosen, you can make the parts far thinner. Your tube can be "dogboned" and turned between threaded ends, to reduce material/weight. Something around .05in should be fine for the Ti. The SS parts can be much thinner, even approaching .035in. Either make the baffle and spacer out of a single piece or alter their design. The spacers don't need that extra shoulder and the baffles don't need any type of mini spacer. They can literally sit right on top of one another. The tube will maintain their alignment, centrally.

For a first go, it's really debatable whether or not to make a "do-all" can. On one hand, it's nice to have the versatility. On the other, it won't give an accurate representation of what a caliber specific design can achieve. Most recommendations, for your first 3 silencers would be one for each: rimfire, 9mm, and 30cal rifle. Rimfire do not require a large design and it's nice to have a small, lightweight suppressor for this type of firearm. A good 9mm suppressor can be used for a variety of platforms (including 357 and 300blk). The ability to swap a booster out makes them great for both pistols and rifles. The 30cal rifle suppressor can be used on almost anything .308 and down. Yes, they can be built for the magnums and most will handle it, but keeping the overall package to a specific point can give ideal results.

Not to dissuade you, just offering honest advice.

[dangerdan0311]

Why did you go with Grade 5 for the tube (assuming you made it yourself)....and not Grade 9 for the tube?

[ECCO Machine]

XD15 seems to be a variant of 440C with inproved corrosion resistance from what I can find. One thing to remember about the 440 class alloys is that, despite being the hardest & strongest of SS alloys, they are not designed for high temperature environments. I can't find the property sheet specific to XD15, but 440C really should not be used in environments that will be in excess of 600°F.

I have and continue to use 440C in some suppressors, namely those for rifle cans that will not see large volume of fire but which burn considerable quantities of powder, such as .338 Lapua. These big rounds blast the baffles with lots of high velocity debris. In these applications, the high hardness will resist erosion better than other alloys.

For hard use applications, I like 422 stainless. It doesn't get quite as hard as 440C, but it is specifically designed to work in 600-1,250°F environments continuously. The bugger is that it's not an easy alloy to get your hands on.

All that said, I use 17-4 in H900 condition for the extreme majority of suppressors I manufacture or recore.

[T-Rex]

@ECCO Machine
This is the best I found, w/ a limited search.

[Imadaddyof7]

So , thanks for the advise and I don't know how to copy people's post and that but I think I will heed your advise and stricktly make this first one for my 9mm nak 9. That being said , yes the XD15 is free also the grade 9 titanium is free. I do have access to unlimited 7075 aluminum also so let's start with a 7.5 inch titanium can for 9mm supers that will also take a few rounds with the 5.56 for light duty. T-rex I will revamp my drawing with your observations and see where this takes me. I am estimating 15.8oz with current design so if I can make things thinner all the better.. I will have a new drawing soon as I prolly still have a few months before work begins lol.... Check is cashed and the weird thing is it was deposited on Martin Luther King day thought the ATF would be closed. Another note machining is not a problem, I can make pretty much anything you can think off beside welding. So maybe if you have a unique idea I can implement that. What are any opinions on a double walled tube like a slip for with a inner area of say .100 where air pressure can walk up the first cone and travel the length of the tubing within that.100 cavity then like normal rest of baffles. I'll provide a quick sketch... Anyway just excited and probably overthinking Abit. Any an all comments are excepted and welcome. I am not an engineer.

[Imadaddyof7]

https://ibb.co/HCF3r8Z


Just an idea

[Imadaddyof7]

Why did you go with Grade 5 for the tube (assuming you made it yourself)....and not Grade 9 for the tube?

Ha ha I did it,.....I have grade 5 round stock to be bored out. Will be making not yet

[whiterussian1974]

Why did you go with Grade 5 for the tube (assuming you made it yourself)....and not Grade 9 for the tube?

Ha ha I did it,.....I have grade 5 round stock to be bored out. Will be making not yet

But he is asking WHY you chose grade 5, instead of grade 9?
Are you stating that you had FREE Gr 5 barstock, and THAT is why you chose it?

[Imadaddyof7]

Why did you go with Grade 5 for the tube (assuming you made it yourself)....and not Grade 9 for the tube?

Ha ha I did it,.....I have grade 5 round stock to be bored out. Will be making not yet

But he is asking WHY you chose grade 5, instead of grade 9?
Are you stating that you had FREE Gr 5 barstock, and THAT is why you chose it?

Yes sorry for confusion,.....

[Imadaddyof7]

I wanted to let everyone know I received my approval today... All paper and mail exccepted on 1-20-20 tax stamp on 3-2-20 that was fast