Tubing thickness for can

[cdhknives]

What are some good rules of thumb for wall thickness on suppressor outer shells? Obviously thicker is stronger but heavier, so the goal is as thin as possible but strong enough:

22 rimfire rifle, 6061-T6 or 7075 AL shell

223/5.56 cf, 7075 AL with good 416SS 1 piece blast chamber and barrel thread (will this work?)

I'm going to start looking for sales on materials and gather parts...

[T-Rex]

For your perusal:

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[cdhknives]

Sorry...guess I didn't go back enough years, and I shoulda figured there was no one willing to give a definitive answer.

Then again if it splits a repair is just a re-machine if the tube.

[propeine]

Sorry...guess I didn't go back enough years, and I shoulda figured there was no one willing to give a definitive answer.

Then again if it splits a repair is just a re-machine if the tube.

and a new tax stamp depending on where the split is. Cannot replace the tube.

Using hoop stress might be a good start. Kind of what those equations were developed for.

[whiterussian1974]

You'll have to determine your own risk tollerance.
A safety factor of 1.5-2 is typical. The blast chamber is sometime 150-200% thicker than the remainder since that's where the "uncorking" stress occurs.
Another way around this is to use a stronger material "spacer" lining the blast chamber. For instance: Ti Tube, SS liner. This also helps to withstand heat stresses and other factors.

I've often thought that a dedicated, sealed blast chamber w external threads should screw into the main tube. Its internal threads would mount directly onto the muzzle. This could even incorporate a 2" reflex volume.
I think that your 3rd line refers to this. Makes alot of sense to me.

[cdhknives]

Using hoop stress might be a good start. Kind of what those equations were developed for.

If I was a mechanical engineer, I'd be happy to. I'm in the electrical world...and a LONG way past college. Plus hoop stress requires a bunch of information I can only guesstimate, like muzzle pressure, and the reaction of 6061-T6 to cyclic strain. The one time I did hoop stress in school we dealt with static pressure, not cyclic, virtually impact, stresses. I've always just erred on the safe side in life, so barring better information I'm going to end up with a really heavy can...yes I can read calipers and make chips on my lathe, and I can follow a diagram to turn out parts, but designing from a white sheet of paper is another level!

Then there is the thread holding ability of thin wall tubing...well hashed here, again, no real conclusions published.

I haven't found anyone admitting to failed tubes. That is the kind of testing I respect most...I guess no one ever blows up a can during testing and admits it...back to the rebuilding cost again...and the commercial manufacturers aren't likely to share as they have a vested interest in keeping design details unpublished so they can sell more cans to us on the fence about building our own.

I guess I need to slow down...I'm bad about jumping in and wanting to get a project done right now! More research...

[Samson104]

I've often thought that a dedicated, sealed blast chamber w external threads should screw into the main tube. Its internal threads would mount directly onto the muzzle. This could even incorporate a 2" reflex volume.
I think that your 3rd line refers to this. Makes alot of sense to me.

Thats exactly how i make mine , rear cap and blast chamber are all one piece with the blast baffle welded to it.

[Scared_of_zombies]

Sorry...guess I didn't go back enough years, and I shoulda figured there was no one willing to give a definitive answer.

Then again if it splits a repair is just a re-machine if the tube.

You need to do some serious reading if youre suggesting AL for a rifle can.

0.065 is the middle of the road answer you seek.

[cdhknives]

When I was thinking about a dual 22lr and 223 can I was thinking 1/8" wall Al or titanium...with some boring to lighten the end. With an integral blast chamber/mount I could see a thinner wall...and the design in my head didn't have a clear path to the can walls either. The baffle spacers were to effectively seal the gases away from the walls...and I could outside turn the low pressure end on a taper to lighten it.

BUT, right now the plans are just floating around in my head...and will continue to change. If it becomes a dedicated 22lr can that is manageable. This question and answer cycle is why I was hoping there were open source (heck I'd even buy a set if they weren't outrageous), proven designs out there...but so far NADA. There is only so much you can design from a cutaway photo on a first build.

[john.t.little1]

1/8" wall Titanium should suffice

[delta9mda]

Do not make rifle cans from aluminum.