View Full Version : 308 can finished and tested

September 24, 2009, 10:36
4130 seamless
2" OD
tube is 0.1" thick in rear and 0.06" thick forward of the blast baffle
Sounds great on the 308 Mauser.

Baffle stack as it fits in the can:

Baffle stack disassembled, note the rear end cap and blast baffle are connected via the threaded spacer, intent was to keep forces off the rest of the baffle stack.

From the other side, you can see the slot and pin hole for a ratcheting attachement I have not finished yet.

On the Mauser

On the 7.62x25AR

Close up of a baffle pre blast/park and drawing showing turning profile

It's real nice oon the bolt gun. The AR is a little noisy due to the gas coming out of the bolt carrier...but still hearing safe.

It compares pretty close (within 6 ounces) to AACs large 338LM cans in size and weight. Weighs 2.8lbs. 12" OAL.

September 24, 2009, 10:50
Why the stair step on the baffles?

September 24, 2009, 11:27
I looked at a lot of the current mfrs designs, and saw that many of them are using some form or other of a stepped cone.

Since my design required at least one step on the front and back of each cone (to locate and index the spacers) I decided it wouldn't be too much more trouble to put in more steps.

The theory, as I understand it, is that the steps help to cause uneven flow, this helps to slow the gases, and that is essentially all a suppressor has to do.

The rest of the design was driven by trying to make it a threaded can, as I do not trust myself to weld 0.06" thick stuff for these pressures, a desire to make it BIG (@"OD x 12" long) since VOLUME can help overcome DESIGN in a can, and the desire to make it as light as possible, thus the reduced diameter spacers with cuts, rather than the more traditional spacers or tube just inside the main can ID.

Prototype Services
September 24, 2009, 17:25
Stimpy, you are my hero!!!!

After I get my SBR closer to finished, I need to discuss my AR45 can idea.


September 24, 2009, 21:22
Originally posted by Prototype Services
Stimpy, you are my hero!!!!

After I get my SBR closer to finished, I need to discuss my AR45 can idea.


Praise from a real machinist...well shucks!

I still await a visit from you to my humble shop.

Prototype Services
September 24, 2009, 22:10
I don't know nuthin' 'bout machinin'... :uhoh:

Did you get flooded out?

September 24, 2009, 22:55
Very nice Stimpy!!!

September 25, 2009, 15:03
looks good. hows it sound. got some video?

September 25, 2009, 15:57
Video just doesn't show suppression very well, the mics or something.

Anyone got a meter?

September 26, 2009, 00:03
Looks good - your not using thread on but a QD atcheting attachement?

September 26, 2009, 11:34
Attachment is threaded 9/16x24 RH

the ratchet design is solely to prevent loosening.

September 26, 2009, 12:00
One of these days I want to hang a can and some night vision on my FAL for nighttime varmint work.

Have you tried this thing on a FAL yet?

Also...how long did it take to machine all this out and what do you think you could make one of these for? Not approachnig you with anything; just generally curious.

September 26, 2009, 14:31
None of my FALs have threaded muzzles, I will be threading my favorite rifle soon and likely also making a custom brakke for it since it will need a thread protector anyway.

Time spent? Hard to say as I did it piecemeal. About 20 hours or so total, that includes a lot of pondering and time spent learning new things.

Must be a big varmint, if it needs a FAL.

September 27, 2009, 16:19
Very neat. How much cash did you end up putting into the suppressor. I think it's cool you can submit a form and make your own. Now I know if the can is destroyed and you wanna make another you must submit paperwork for a new one. But say if you came up with a better baffle design. You could just replace the baffles and destroy the old ones right? Is just the body considered the registered part?? I've never owned a suppressor so i'm assuming some part has a serial number or something on it right?

September 27, 2009, 20:19
$200 stamp
$60 or so worth of materials.
Lots of time thinking about it.
2 fairly serious cuts.

Form1's are *NOT* licenses to tinker. As the mfr I can replace parts that fail, but the intent is not to let you make design after design on the single approval.

This one is plenty quiet for me, and about all I can see doing to it now is finishing the ratchet and removing some material to make it a tad lighter.

September 27, 2009, 20:29
You are quite gifted thank you for sharing.

September 29, 2009, 21:36
Originally posted by stimpsonjcat
Must be a big varmint, if it needs a FAL.

Coyotes and big feral hogs at night. A good friend of mine's family owns a farm and raises exotic deer. They've had a lot of problems with coyotes killing their deer and hogs destroying their feed plots. Naturally I want to help out. I also saw an opportunity to justify purchasing some new equipment!:angel:

And...I continue to be amazed at the stuff you and your machine shop can come up with. Keep up the good work!

The Armour
February 22, 2010, 18:57
VERY NICE looking can you got there Stimpy, And thats coming from a Machinist too. I would have expected nothing less from you though after seeing the Worlds Greatest Beer Tap in your basement and the only 8mm FAL known to man. Fantastic bro. Maybe I can run down with Rooster this year for the FAL match and get a closer look at some more of your creations, but from the pics it looks GREAT. Keep up the good work.

February 22, 2010, 20:39

I'm waiting for BATF approval on a store bought(M42K) can but want to build a 223 suppressor

One of the problems being encountered is wall thickness data
If you were building a 223 can with 304 SS seamless tubing, what would be a good number for wall thickness?
Would 4130 or 4140 be better than the 304SS I was planning on using?

Can will be 2''OD, 8" long and have a 4" blast chamber

BTW, looks like you built a great can

February 22, 2010, 22:25
GREAT JOB! You ought to put that can on the 8mm FAL. It looks beefy enough! That would be the ultimate cool...

p.s. I have the reaper with 8mm FAL as my background.:biggrin:

p.s.s. You are my hero for doing that, BTW.:beer:

one hand clapping
February 23, 2010, 12:22
Impressive !!
Those who produce items of value with their own hands will be the salvation of our way of life.
very nice work Sir.

L Haney
February 23, 2010, 16:54
Stimpy, is the sound reduction in full blown 7.62 Nato enough to shoot without hearing protection? I got to thinkin' about this and realized I'd never been around a suppressed .308 before. Handgun calibers and .223, but not something this hot.


February 24, 2010, 12:30
Thanks for all the compliments...I learned a lot making this.

I haven't shot it a lot as my club is still can-phobic until the new rulebook gets printed. But I think it is hearing safe. I have modified a spare gas plug by welding up the hole and redrilling a smaller hole and also welding in the notch that feeds to the gas collar. I hope to tune this to where the rifle cycles fine with the can but isn't overpressured as I think the less gas coming out the bleed hole the quieter the rifle will sound.

The can is plenty quiet on the bolt gun.

Alaska...it's a Nazgul, not the reaper. Though I guess it works either way.

Wall thickness? well this one is 0.1" foor the blast chamber and drops to 0.065" for the rest. I don't want to get into recommending anything though, I am not a professional can maker. Choose yoour own doom. :biggrin:

February 27, 2010, 19:03
Modified gas plug functions perfectly.

Rifle cycles with the modified plug and the can installed without changing the gas setting.