300 BLK design

[LavaRed]

Ported spacers that are smaller than the suppressor ID offer improved gas delay while also optimizing volume and reducing weight. Spacing is also critical. Note that the gases lose pressure in every subsequent chamber, so that for a given longitudinal distance, a gas particle will travel a lesser distance axially; i.e., the gas will have less tendency to expand. Therefore, the first baffles should be spaced closer, and the spacing should increase towards the exit. Not the other way around, contrary to what most do.
With your projected length and OD, I'd probably have a blast chamber of about 2", followed by some 10 cone baffles starting at 1/2" spacing and gradually increasing to 1" spacing at the end. About 1" OD for the spacers should do it. Endcaps no thicker than 1/4" each. Anything else is a waste of volume.

While agreeing w most of what you say, I must take exception w 1 aspect b/c you didn't address gas jet velocity. Yes, trapping small packets of high pressure gases early makes good sense.

But, one must consider that gas jets traveling supersonic unpon leaving the barrel will enter Choked Flow conditions and must drop velocity b/f they can spread to fill the OD properly. So, if not enough linear distance b/t baffles, the core of jet will pass through into the next chamber w/o properly expanding to fill the volume.

Well, I think this is precisely why gradually increasing spacing is better. It gives the gas jet more distance to expand as it loses velocity.

About the spacers, I guess I can see the point of view, at least for cans with OD's of around 1.5".
Thanks for the explanation.

[whiterussian1974]

But, one must consider that gas jets traveling supersonic unpon leaving the barrel will enter Choked Flow conditions and must drop velocity b/f they can spread to fill the OD properly. So, if not enough linear distance b/t baffles, the core of jet will pass through into the next chamber w/o properly expanding to fill the volume.

Well, I think this is precisely why gradually increasing spacing is better. It gives the gas jet more distance to expand as it loses velocity.

So that the gas exits the tube b/f it can radially expand into the 1st few baffles?

[LavaRed]

But, one must consider that gas jets traveling supersonic unpon leaving the barrel will enter Choked Flow conditions and must drop velocity b/f they can spread to fill the OD properly. So, if not enough linear distance b/t baffles, the core of jet will pass through into the next chamber w/o properly expanding to fill the volume.

Well, I think this is precisely why gradually increasing spacing is better. It gives the gas jet more distance to expand as it loses velocity.

So that the gas exits the tube b/f it can radially expand into the 1st few baffles?

It's all relative. You space the first few baffles well enough that the gases can expand in them properly, and then you gradually increase that spacing even more! Then you get the best of both worlds. Having increasing instead of decreasing spacing doesn't mean that one must sacrifice linear distance between baffles.

[fishman]

It's all relative. You space the first few baffles well enough that the gases can expand in them properly, and then you gradually increase that spacing even more

have you tested this? i understand your theory behind it but im not 100% sold that increasing spacing would be better than decreasing or constant. it would be cool to make a silencer with different sized spacers and be able to test it with the spacers increasing and decreasing and see for sure which one works better.

[LavaRed]

It's all relative. You space the first few baffles well enough that the gases can expand in them properly, and then you gradually increase that spacing even more

have you tested this? i understand your theory behind it but im not 100% sold that increasing spacing would be better than decreasing or constant. it would be cool to make a silencer with different sized spacers and be able to test it with the spacers increasing and decreasing and see for sure which one works better.

It worked for me back when I tested my variable spacing can.

[Capt. Link.]

It's all relative. You space the first few baffles well enough that the gases can expand in them properly, and then you gradually increase that spacing even more

have you tested this? i understand your theory behind it but im not 100% sold that increasing spacing would be better than decreasing or constant. it would be cool to make a silencer with different sized spacers and be able to test it with the spacers increasing and decreasing and see for sure which one works better.

Not a theory its a fact.I tested it along with variable porting ie: ports that get larger as the pressure is reduced.Both work on the same principles.This one uses the reverse variable spacing. https://youtu.be/P4TNpk6yYcQ

[whiterussian1974]

Not a theory its a fact.I tested it along with variable porting ie: ports that get larger as the pressure is reduced.Both work on the same principles.This one uses the reverse variable spacing. https://youtu.be/P4TNpk6yYcQ

That vid was w a 22lr. Does it work for .308?

22lr won't suffer the same supercritical choked flow problems. Neither would most pistol rds. But for .30-.50 supers I'd hope that there was additional testing.

[fishman]

It's all relative. You space the first few baffles well enough that the gases can expand in them properly, and then you gradually increase that spacing even more

have you tested this? i understand your theory behind it but im not 100% sold that increasing spacing would be better than decreasing or constant. it would be cool to make a silencer with different sized spacers and be able to test it with the spacers increasing and decreasing and see for sure which one works better.

Not a theory its a fact.I tested it along with variable porting ie: ports that get larger as the pressure is reduced.Both work on the same principles.This one uses the reverse variable spacing. https://youtu.be/P4TNpk6yYcQ

awesome info guys, thanks

[fishman]

heres the most updated design based on all your advice

im going to clip and port the cones, i just didnt show it in the drawing.

i went with spacer diameter as large as possible because i think that design would work best on my .270 as well as working very well on 300 blackout

[silencer_kid]

have you tested this? i understand your theory behind it but im not 100% sold that increasing spacing would be better than decreasing or constant. it would be cool to make a silencer with different sized spacers and be able to test it with the spacers increasing and decreasing and see for sure which one works better.

why would it be cool? make some spacers, go shoot,......., make some spacers, go shoot,.......,make some spacers, go shoot,.......,make some spacers, go shoot,.......,make some spacers, go shoot,.......,make some spacers, go shoot,.......,make some spacers, go shoot,.......,make some spacers, go shoot,.......,make some spacers, go shoot


.......keep the best setup you find.

[LavaRed]

heres the most updated design based on all your advice

im going to clip and port the cones, i just didnt show it in the drawing.

i went with spacer diameter as large as possible because i think that design would work best on my .270 as well as working very well on 300 blackout

The endcaps are still too thick. Encaps that are 1/4" total thickness, with 3/16" engagement thickness are enough for either threading or welding. And you get extra volume!

[fishman]

have you tested this? i understand your theory behind it but im not 100% sold that increasing spacing would be better than decreasing or constant. it would be cool to make a silencer with different sized spacers and be able to test it with the spacers increasing and decreasing and see for sure which one works better.

why would it be cool? make some spacers, go shoot,......., make some spacers, go shoot,.......,make some spacers, go shoot,.......,make some spacers, go shoot,.......,make some spacers, go shoot,.......,make some spacers, go shoot,.......,make some spacers, go shoot,.......,make some spacers, go shoot,.......,make some spacers, go shoot


.......keep the best setup you find.

On a serviceable silencer, sure. But that won't work with one that's welded shut

[fishman]

heres the most updated design based on all your advice

im going to clip and port the cones, i just didnt show it in the drawing.

i went with spacer diameter as large as possible because i think that design would work best on my .270 as well as working very well on 300 blackout

The endcaps are still too thick. Encaps that are 1/4" total thickness, with 3/16" engagement thickness are enough for either threading or welding. And you get extra volume!

The rear cap is .62", the same depth of thread on a threaded barrel, I figured I'd want as much thread engagement as possible to keep the tube concentric with the barrel. The making the front cap Less wide would require me to lengthen that last spacer, not saving me weight or adding volume

[silencer_kid]

have you tested this? i understand your theory behind it but im not 100% sold that increasing spacing would be better than decreasing or constant. it would be cool to make a silencer with different sized spacers and be able to test it with the spacers increasing and decreasing and see for sure which one works better.

why would it be cool? make some spacers, go shoot,......., make some spacers, go shoot,.......,make some spacers, go shoot,.......,make some spacers, go shoot,.......,make some spacers, go shoot,.......,make some spacers, go shoot,.......,make some spacers, go shoot,.......,make some spacers, go shoot,.......,make some spacers, go shoot


.......keep the best setup you find.

On a serviceable silencer, sure. But that won't work with one that's welded shut

make one cap threaded, weld up later.

[whiterussian1974]

Fishman: DrK says that the pockets in rear endcap will fill w carbon.
You could connect each pair of holes but leave the web b/t 2nd and 3rd holes. That retains the rigidity and quenching surface, but frees up some volume and allows carbon to shake loose under blast.

[whiterussian1974]

why would it be cool? make some spacers, go shoot,......., make some spacers, go shoot,.......,make some spacers, go shoot,.......,make some spacers, go shoot,.......,make some spacers, go shoot,.......,make some spacers, go shoot,.......,make some spacers, go shoot,.......,make some spacers, go shoot,.......,make some spacers, go shoot

.......keep the best setup you find.

On a serviceable silencer, sure. But that won't work with one that's welded shut

make one cap threaded, weld up later.

https://www.law.cornell.edu/uscode/text/18/371
http://uscode.house.gov/statviewer.htm? ... 2&page=701
Chap19, Sec371 punishable by up to $10,000 and 5yrs in Prison.
Please don't make me into the "bad guy."
You can rearrange the baffles, but not repeatedly make them.

[Samson1044]

heres the most updated design based on all your advice

im going to clip and port the cones, i just didnt show it in the drawing.

i went with spacer diameter as large as possible because i think that design would work best on my .270 as well as working very well on 300 blackout

The endcaps are still too thick. Encaps that are 1/4" total thickness, with 3/16" engagement thickness are enough for either threading or welding. And you get extra volume!

The rear cap is .62", the same depth of thread on a threaded barrel, I figured I'd want as much thread engagement as possible to keep the tube concentric with the barrel. The making the front cap Less wide would require me to lengthen that last spacer, not saving me weight or adding volume

80% of the thread load is on the first 4 threads , you can get away with 6 threads , 8 for sure.

[fishman]

80% of the thread load is on the first 4 threads , you can get away with 6 threads , 8 for sure.

thats entirely dependant on thread pitch and material...
8 steel threads of 14 TPI vs. 8 aluminum threads of 32 TPI will make a huge difference in thread strength.

[LavaRed]

For your rear endcap, you could remove the little holes, which as stated will probably get clogged, and instead make the endcap thinner, with a little "neck" for the barrel threads. This reduces weight. Or it can even result in a shorter suppressor. Right now your endcaps look to be about 5/8" thick. If you reduce both of them to 1/4" thick, you'd be saving a full 3/4" of length. Which you could use either for a shorter can, or one more baffle.

[silencer_kid]

https://www.law.cornell.edu/uscode/text/18/371
http://uscode.house.gov/statviewer.htm? ... 2&page=701
Chap19, Sec371 punishable by up to $10,000 and 5yrs in Prison.
Please don't make me into the "bad guy."
You can rearrange the baffles, but not repeatedly make them.

1) and the timeline for a F1 maker to build his can is ???????? let me know when you find it.
2) dream on, i can machine 8-10 baffles at a time for my F1 can, because at any given time the can can hold that many, but, at any given time i have no more than 8-10. or, i have only one useable mono-core, the others that are in the smelter pile were machined wrong (i am such a shiat machinist, etc), thus if ATF comes knocking i let them in, i can even show them the pile of scrap crap that didnt get machined properly and cannot be used in a can. one F1, one can, two F1's, two cans, w/ a pile of scrap.
3) obvious you are not a lawyer, so no real reason for you to provide links to laws
4) you do know the real purpose of F1, right?

[whiterussian1974]

https://www.law.cornell.edu/uscode/text/18/371
http://uscode.house.gov/statviewer.htm? ... 2&page=701
Chap19, Sec371 punishable by up to $10,000 and 5yrs in Prison.
Please don't make me into the "bad guy."
You can rearrange the baffles, but not repeatedly make them.

1) and the timeline for a F1 maker to build his can is ???????? let me know when you find it.
2) dream on, i can machine 8-10 baffles at a time for my F1 can, because at any given time the can can hold that many, but, at any given time i have no more than 8-10. or, i have only one useable mono-core, the others that are in the smelter pile were machined wrong (i am such a shiat machinist, etc), thus if ATF comes knocking i let them in, i can even show them the pile of scrap crap that didnt get machined properly and cannot be used in a can. one F1, one can, two F1's, two cans, w/ a pile of scrap.
3) obvious you are not a lawyer, so no real reason for you to provide links to laws
4) you do know the real purpose of F1, right?

1. Until complete.
2. As long as you are SOT 7/02 then that is completely correct. If not, 5yrs.
3. I enforce laws, not argue or interpret them.
4. For non-commercial builds of single NFA items. Not multiple tries until you get it right. Only SOTs can "research" through trial and error.

Bender: you love schooling fools. Take this schlub to task.

[mr fixit]

4) you do know the real purpose of F1, right?

A source of endless questions, and debate on forums?




s

[silencer_kid]

1. Until complete.
2. As long as you are SOT 7/02 then that is completely correct. If not, 5yrs.
3. I enforce laws, not argue or interpret them.
4. For non-commercial builds of single NFA items. Not multiple tries until you get it right. Only SOTs can "research" through trial and error.

Bender: you love schooling fools. Take this schlub to task.

well, i had a long reply, but simply back-spaced over it.
hmmm, "until complete". wonder if the authors forgot some verbiage along the way.
but ok, you keep on enforcing, i am ok with that.

and btw, one must interpret before being able to enforce the laws, the cognitive process does not allow any other path. a radar gun provides quantitative evidence for interpretation, however, pulling me over because you thought i ran a red light may or may not have merit but you interpreted the law in a way that told you i was breaking the law. this is why its so much more fun being a lawyer and not an enforcer of laws.

[whiterussian1974]

Bender: you love schooling fools. Take this schlub to task.

well, i had a long reply, but simply back-spaced over it.
hmmm, "until complete". wonder if the authors forgot some verbiage along the way.
but ok, you keep on enforcing, i am ok with that.

and btw, one must interpret before being able to enforce the laws, the cognitive process does not allow any other path. a radar gun provides quantitative evidence for interpretation, however, pulling me over because you thought i ran a red light may or may not have merit but you interpreted the law in a way that told you i was breaking the law. this is why its so much more fun being a lawyer and not an enforcer of laws.

You have little control over my continued Employment ragardless of your acceptance or not.

Interpretting my observations and interpretting the Law are 2 separate functions.

The Law isn't Science. We aren't concerned w Reality, just Substantiated Facts that may or may not be based in Reality. Only Jurors are Finders of Fact. That's 1 of many reasons why some trials go forward even though any reasonable person would tend to conclude a clear verdict based upon a Summary Hearing of the Evidence. Victims are allowed THEIR day in court, too.

[silencer_kid]

The Law isn't Science. We aren't concerned w Reality, just Substantiated Facts that may or may not be based in Reality. Only Jurors are Finders of Fact. That's 1 of many reasons why some trials go forward even though any reasonable person would tend to conclude a clear verdict based upon a Summary Hearing of the Evidence. Victims are allowed THEIR day in court, too.

ok, sounds good.