Blast Baffle

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Bill G
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Blast Baffle

Post by Bill G »

I will be building a Suppressor for a 300 Whisper, it will be made from aluminium and will be of a monocore construction. I have read about the wear on the blast baffle from the gasses, and most people state that stainles steel would be the prefered material to use for the blast baffle. My question is, how many rounds would it take to make a noticeable difference in the performance of the suppressor. I would be using subsonic loads almost exclusively for hunting. The rifle will be a bolt gun and would not see a lot of repeated use, so excessive heat should/may not be a problem

I have the bar stock now, but I am unsure of the grade. I was told that it machines well, so we will see what happens. The outer tube will be from a Mares pneumatic speargun, it is made from stainless steel with a 1.5mm wall thickness. The outer tube will not be threaded as the end cap will srew into the monocore which will hold the outer tube in compression. I am seriously thinking of an over barrel suppressor which will give a larger blast chamber as compared to a muzzle forward suppressor, just in case I use supersonic rounds in the future. Does anyone see any problems using this stainless outer tube.

Cheers, Bill
mg81
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Re: Blast Baffle

Post by mg81 »

Will your design let you put in some sort of insert (like a quality, large dia. bolt threaded into the mono core than machined out) or an overlay (like a piece of stainless steel sheet) on the blast face to take the abuse. It would not have to be very thick, to give good wear resistance.
JimmyB
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Re: Blast Baffle

Post by JimmyB »

I have no idea what the dimensions will be of your monocore but what I use is 1.5 dia7075 round stock
The round stock can be ordered from online metals.com for $26/ft

For the tube 4130 seamless 1.5 OD x .058 wall thickness @ $13/ft from onlinemetals

Total price of $40 plus shipping

For the blast chamber, I use seamless Stainless Steel tubing .75 OD or 1” OD x .065 wall thickness @ 10/ft
Also from onlinemetals
I use the tubing as an insert

$50 plus shipping for excellent materials of know quality is a much better bet than piecing together stuff you have laying around
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Capt. Link.
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Re: Blast Baffle

Post by Capt. Link. »

Subsonic whispers are fairly low pressure.You would experience little erosion with any metal but it you wish to do it only once try SS and have it hardened.
The only reason after 243 years the government now wants to disarm you is they intend to do something you would shoot them for!
http://www.silencertalk.com/forum/viewtopic.php?f=10&t=79895
Bill G
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Re: Blast Baffle

Post by Bill G »

Well I got the can made and it is not very quiet, not load but not quiet. I'd say about .22 rim fire without the crack, easily shot without wearing hearing protection. Not too sure where I went wrong here. How big a dia should the bullet path hole be? Mine is .375, which was suggested on here somewhere as a max. I've no idea how to post a picture, but if someone could help me out here I'll see what I can do. And then one and all can give me thier thoughts.
57fairlane
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Re: Blast Baffle

Post by 57fairlane »

7075 aluminum *should* be fine.

I honestly would run a 17-4ph stainless blast baffle. Heat-treated you wouldn't have any problem with subsonic 300.
Historian
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Re: Blast Baffle

Post by Historian »

Adding nothing of note to the excellent advice, as usual, of Capt. Link, MG81, and JimmyB,
if your ID is .75" it turns out that the air pistol/soda maker CO2 cylinders are steel
and .75" OD. There is a little MacGyver in all of us. :)
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redtazdog
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Re: Blast Baffle

Post by redtazdog »

Post some pictures of it then some of us here may come up with idea's
on how to help make it quieter.
BELT_FED
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Re: Blast Baffle

Post by BELT_FED »

The .375 is plenty small enough if you have a good baffel design. My 300 blk (whisper) can actually has a .430 bore so I can squeeze a 338 through it. And everyone has heard my rifle its in a thread here also. Two things I did notice when I built the can was that more baffles didnt make for a quieter can. Spacing made a huge difference with subsonic pressures. The other biggy was the powder I chose for it. 5 gr of hp38 is funny its so quiet. 8.7gr of H110 was alot louder at the same fps. and 1680 was worse. If your not shooting an auto loader stick with the "faster" powders. My favorite load right now is 8 gr of lil gun behind a 175 gr smk that I get pulled from m118lr bullets for about 14 cents each. These shoot 1 moa at 100yds most of the time with the "pulled bullet" flyer ever now and again.

Remember that subsonic loads dont have the pressure to push out into alot of small spaced baffles the gas will follow the path of least resistance. Or atleast this was my thoughts. My can is twice as quiet with the stepped "omega" style baffels as it was with closer spaced stepped cones
Historian
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Re: Blast Baffle

Post by Historian »

Capt. Link. wrote:Subsonic whispers are fairly low pressure.You would experience little erosion with any metal but it you wish to do it only once try SS and have it hardened.
Along with this good advice is an interesting method for hardening and tempering that I found
on a great site I frequently visit:

Hardening A Milling Cutter=>
<< http://mikesworkshop.weebly.com/rotary-broaching.html >>
Bill G
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Re: Blast Baffle

Post by Bill G »

I've got a photo, but can somebody help me post it.
ranb
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Re: Blast Baffle

Post by ranb »

If it is not digital, scan it and save it as a jpeg. Make an account at www.photobucket.com or another site and upload it. Then simply paste the link so we can see it.

Ranb
SilencerTalk was a place I could disccuss making registered silencers without being told I was a criminal. That is no longer true. http://www.silencertalk.com/forum/viewtopic.php?f=132&t=99273
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redtazdog
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Re: Blast Baffle

Post by redtazdog »

Bill G wrote:I've got a photo, but can somebody help me post it.
If you dont want to open a photobucket acct you can email the picture to me and I will use my acct to post them for you.
SRM
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Re: Blast Baffle

Post by SRM »

Imgur is pretty easy to use.
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