bounceing ideas for a big can

Yes, it can be legal to make a silencer. For everything Form-1, from silencer designs that are easily made, to filing forms with the BATF, to 3D modeling. Remember, you must have an approved BATF Form-1 to make a silencer. All NFA laws apply.

Moderators: mpallett, bakerjw

Post Reply
sharpshooter3006
New Member
Posts: 6
Joined: Sun Aug 11, 2013 1:05 pm

bounceing ideas for a big can

Post by sharpshooter3006 » Wed Dec 25, 2013 4:40 am

So after stalking this site for years and watching some amazing builds happen it is time for my 50 bmg to get a can.
I want to do a reflex style can with a muzzle brake integrated into it. Similar to what JohnnyO did for his amazing can.
I have 18" of free barrel to work with before the hand-guard and i am planning on doing 3.5" outer diameter. I was thinking that the overall length may be close to 36". Everything will be most likely made out of stainless, and I would also like to make it to be user serviceable.
Any suggestions would be greatly appreciated and thank you in advance for any help.


a general idea and crappy paint rendition of my idea. not to scale http://www.flickr.com/photos/[email protected]/11543751346/
http://www.flickr.com/photos/[email protected]/11543751346/


posts I got ideas from
viewtopic.php?f=10&t=20992
viewtopic.php?f=10&t=62370

And Merry Christmas

User avatar
doubloon
Silent But Deadly
Posts: 11901
Joined: Thu Jan 01, 2009 1:02 am
Location: Houston-ish

Re: bounceing ideas for a big can

Post by doubloon » Wed Dec 25, 2013 9:05 am

What wall thickness you thinking about?

For comparison the Cyclops is 2.5" OD, around 16" long and comes in around 5lbs

36" of 3.5" OD stainless at 0.12" thick is going to be about 7lbs+, 0.22" thick is headed for 13lbs+ ... both before end caps and baffles ... and that doesn't include the sherpa.

Merry Christmas
http://www.youtube.com/watch?v=BDtd2jNIwAU MUSAFAR!
http://www.youtube.com/watch?v=8CrOL-ydFMI This is Water DavidW
Complete Form 1s http://www.silencertalk.com/forum/viewtopic.php?f=10&t=79895

User avatar
Wicked
Silent But Deadly
Posts: 1438
Joined: Fri Feb 20, 2009 3:15 am
Location: Dayton, OH
Contact:

Re: bounceing ideas for a big can

Post by Wicked » Wed Dec 25, 2013 3:27 pm

sharpshooter3006 wrote:i am planning on doing 3.5" outer diameter. I was thinking that the overall length may be close to 36". Everything will be most likely made out of stainless
That going to be HUGE! And a real heavy duty chunk. That big on a 20mm bolt gun, maybe. I saw one that looked like the muffler from a Mack truck hanging off the end of the 6 ft barrel.

There is a point of diminishing returns with regards to diameter, length, wall thickness, number of baffles, ect. Exactly where that point is....well, that's the tricky part.

My theory has been to look at proven industry performers for design ideas. You most likely will not come up with an overall design that will out-do the real pros. Not advocating directly ripping off, but more like use them for broad guidelines. Those guys have funding, equipment and engineerds on staff to develop products that work. A little bigger or smaller or longer or shorter (or whatever) and you're still probably in the park. Stray too far and I'm guessing you're getting off into places that do not make sense.

That said, volume is your friend and even more so with a less efficient design. But, the reflex portion of the can will be largely wasted space and added weight. A can that big would sound OK with flat washer baffles. I'm sure that's why most F1 cans end up big and heavy. If you don't mind the weight (plus brake) and length your proposed design would add, then try it. A tripod mount may be in order! Not sure I've seen any other examples that size but it's an interesting concept.
https://www.facebook.com/wickedweapons

sharpshooter3006
New Member
Posts: 6
Joined: Sun Aug 11, 2013 1:05 pm

Re: bounceing ideas for a big can

Post by sharpshooter3006 » Wed Dec 25, 2013 4:12 pm

The original weapon weights 29 pounds so whats another 10 but more weight to absorb recoil. I under stand that volume is my friend but I think that is is possible that I may be over engineering this can a bit.

Fulmen
Silent But Deadly
Posts: 1045
Joined: Wed Feb 04, 2009 8:36 am

Re: bounceing ideas for a big can

Post by Fulmen » Wed Dec 25, 2013 4:25 pm

Wicked wrote:the reflex portion of the can will be largely wasted space and added weight.
That depends on how you look at things. It is true that a telescopic can of a given length will be less effective than a front-mounted one of the same design, but for a given build length it will be better. And while it will still be heavier it will not make the gun as front heavy or long, something I personally find just as important as weight alone. The double mount also protects the muzzle from bending forces if the can is subjected to heavy sideways loads.

As for the size I'd start by comparing the powder charge with say a 308 or another caliber you have more experience with.

User avatar
delta9mda
Silent But Deadly
Posts: 2304
Joined: Wed Dec 07, 2005 4:32 pm
Location: miami, florida

Re: bounceing ideas for a big can

Post by delta9mda » Wed Dec 25, 2013 9:47 pm

If you already have the 3.5" od tube use it but go 16".
Yes you are over thinking.
NP

sharpshooter3006
New Member
Posts: 6
Joined: Sun Aug 11, 2013 1:05 pm

Re: bounceing ideas for a big can

Post by sharpshooter3006 » Thu Dec 26, 2013 3:32 pm

I have not purchased any material yet so I'm not dead set on 3.5". That is just the larges diameter that will not block my scope. I was figuring to make this can as voluminous as I could, but it is looking like I am overshooting the moon.

Fulmen
Silent But Deadly
Posts: 1045
Joined: Wed Feb 04, 2009 8:36 am

Re: bounceing ideas for a big can

Post by Fulmen » Thu Dec 26, 2013 3:44 pm

Well, a 50BMG uses 200-250grs of powder, right? So it's in the range of 5 times what a 308 uses. Now take the cubic root of 5 and you get 1.7.

So if we start with the proposed size (3.5x18") and scale it down to a 308 it would be 2x10,5". I know it's a rough estimate at best, but it provides some sense of scale...

User avatar
Dr.K
Silent But Deadly
Posts: 632
Joined: Sun Jun 10, 2007 9:32 pm
Location: Webster Parish

Re: bounceing ideas for a big can

Post by Dr.K » Thu Dec 26, 2013 4:29 pm

Fulmen wrote:Well, a 50BMG uses 200-250grs of powder, right? So it's in the range of 5 times what a 308 uses. Now take the cubic root of 5 and you get 1.7.

So if we start with the proposed size (3.5x18") and scale it down to a 308 it would be 2x10,5". I know it's a rough estimate at best, but it provides some sense of scale...
True, but you must also consider bore volume!

There is a huge amount of extra bore volume that the powder is expanding in ;)
Kyle O.

Fulmen
Silent But Deadly
Posts: 1045
Joined: Wed Feb 04, 2009 8:36 am

Re: bounceing ideas for a big can

Post by Fulmen » Thu Dec 26, 2013 5:42 pm

Actually the .50 has less than three times the cross section, so with the same barrel length it will have less volume compared to the powder charge than a 308. If we ignore the chamber volume for simplicity's sake the .50 would require roughly twice the barrel length to be proportional to the 308.

User avatar
Dr.K
Silent But Deadly
Posts: 632
Joined: Sun Jun 10, 2007 9:32 pm
Location: Webster Parish

Re: bounceing ideas for a big can

Post by Dr.K » Thu Dec 26, 2013 7:27 pm

Fulmen wrote:Actually the .50 has less than three times the cross section, so with the same barrel length it will have less volume compared to the powder charge than a 308. If we ignore the chamber volume for simplicity's sake the .50 would require roughly twice the barrel length to be proportional to the 308.
so a .308" bore tube that is the same exact length as a .500" bore tube has more volume.

Please explain to me how?
Kyle O.

Fulmen
Silent But Deadly
Posts: 1045
Joined: Wed Feb 04, 2009 8:36 am

Re: bounceing ideas for a big can

Post by Fulmen » Thu Dec 26, 2013 7:48 pm

Sorry if I was unclear, the volume of the .50 is obviously greater. But you must compare the volume to the volume of the gases released by the powder, and while a .50 will produce 5-6 times more gas than the 308, while the barrel only has 3 times the volume. But fine, lets look at it another way: If you scale a 24" barreled 308 with a can measuring 2x10" proportionally up to 50BMG you'll get a 40" barrel and a can measuring 3.5x18".

User avatar
john.t.little1
Silent But Deadly
Posts: 243
Joined: Thu Nov 24, 2011 2:13 pm
Location: florida/iraq

Re: bounceing ideas for a big can

Post by john.t.little1 » Thu Dec 26, 2013 7:59 pm

I'm confused... Look around at what most "pro" suppressor company's .50 cans specs are most are going to be same dia if they are making them that way a lot of R&D went into it follow suit doe
"A man is known by the silence he keeps. - Oliver Herford"
"Gunpowder, treason and plot. I see no reason why gunpowder, treason
Should ever be forgot..."

User avatar
Dr.K
Silent But Deadly
Posts: 632
Joined: Sun Jun 10, 2007 9:32 pm
Location: Webster Parish

Re: bounceing ideas for a big can

Post by Dr.K » Thu Dec 26, 2013 8:06 pm

Fulmen wrote:Sorry if I was unclear, the volume of the .50 is obviously greater. But you must compare the volume to the volume of the gases released by the powder, and while a .50 will produce 5-6 times more gas than the 308, while the barrel only has 3 times the volume. But fine, lets look at it another way: If you scale a 24" barreled 308 with a can measuring 2x10" proportionally up to 50BMG you'll get a 40" barrel and a can measuring 3.5x18".
Ok, I'm on the same page with you now. But, we have to consider every factor, it's not "just" volume involved here.

Overbuilding is fine, I just can't see the point in 10x overbuilding :lol:
Kyle O.

User avatar
delta9mda
Silent But Deadly
Posts: 2304
Joined: Wed Dec 07, 2005 4:32 pm
Location: miami, florida

Re: bounceing ideas for a big can

Post by delta9mda » Thu Dec 26, 2013 8:08 pm

Stop making this harder than it has to be.
Jlittle nailed. Make your 50 about the same size as what is commercially done.
This isn't rocket surgery 8)
NP

Fulmen
Silent But Deadly
Posts: 1045
Joined: Wed Feb 04, 2009 8:36 am

Re: bounceing ideas for a big can

Post by Fulmen » Fri Dec 27, 2013 6:37 am

Dr.K wrote:we have to consider every factor, it's not "just" volume involved here
I agree, I just wanted to show how you can ballpark something with simple math. Looking at commercial cans would of course be my first stop as well, but it's still hard to get a sense of scale when dealing with a round that burns 5-6 times more powder than what I'm used to. And the primary design criteria is volume, ie the volume of the can compared to the pressure and volume of the gas it needs to handle.

In this case the 3.5x18" tube seems extreme until you scale it down, then it becomes roughly 2x10". While I wouldn't call that a small can for a 308 I wouldn't call it excessive either. It will at least provide some sense of scale when looking at commercial 50-cans.

Hard_ware
Senior Silent Operator
Posts: 121
Joined: Thu Aug 29, 2013 6:56 pm
Location: South South Texas

Re: bounceing ideas for a big can

Post by Hard_ware » Sat Dec 28, 2013 3:44 pm

I think a reflex can as long as possible will eliminate some barrel flex as well, by stiffening the barrel.

http://www.youtube.com/watch?v=s5pVya7eask
NRA Life Member

User avatar
jimmym40a2
Elite Member
Posts: 2745
Joined: Sun May 06, 2007 9:25 pm
Location: Colorado (for Mongo)

Re: bounceing ideas for a big can

Post by jimmym40a2 » Sat Dec 28, 2013 8:34 pm

That would be huge. Mine is overkill and its 3 inches dia.
http://www.youtube.com/watch?v=nEZJ_C4LwzA

S4area51
Member
Posts: 15
Joined: Wed Oct 30, 2013 1:14 am

Re: bounceing ideas for a big can

Post by S4area51 » Tue Dec 31, 2013 1:17 am

For size reference;
Osprey 45 vs AAC Cyclops
:shock:
Image

User avatar
Wicked
Silent But Deadly
Posts: 1438
Joined: Fri Feb 20, 2009 3:15 am
Location: Dayton, OH
Contact:

Re: bounceing ideas for a big can

Post by Wicked » Tue Dec 31, 2013 6:48 am

What is the Brand and Model of the Cyclops case?
https://www.facebook.com/wickedweapons

Post Reply