.223/5.56 Material Question

[fdv99]

I'm thinking about building a can with simple cone baffles and spacers for an 16" ar-15. If a stainless blast baffle and initial spacer are used, would it be safe to use aluminum for the rest? I was thinking something like an .09" wall thickness for the outer tube, .065 for the spacers and .08-.1 for the baffles?

Any help would be greatly appreciated.

[Bowen1911]

I would strongly recommend against aluminum in any high pressure generating cartridge, and on any high velocity cartridge.

[fdv99]

ok, would normal carbon steel work? like 4130, about .065 thick? I would do the calculations like in the suppressor design thread but im having trouble finding the chamber and bore pressure right before the bullet leaves the barrel.

[delta9mda]

4130 will work. .065" plus your spacers added (.035-.05" thick) should do it.

[ghostdog662]

I am in the process of making one from 7075 baffles and 2024 tubes. This will be on a bolt gun though so it will not be put to the extreme rapid fire situations you would encounter on AR's. The 7075/2024 is almost identical to the 4130 as far as strength goes but you can't get it very hot because the aluminum loses fatigue strength.

You may want to consider using 304 SS tube for your spacers and expansion chamber because it will be significantly lighter than 4130. Stay away from 304 SS as baffles though. It's machinability is very very low and work hardens if you do not know what you are doing. The 303 is easy to machine but not weldable. 304 is difficult to machine but is weldable. If only they made tubes from 303 it would be great in a threaded cap suppressor.

[Machine Gun Matt]

Stay away from 304 SS as baffles though. It's machinability is very very low and work hardens if you do not know what you are doing. 304 is difficult to machine but is weldable.

I do hope your kidding

[ghostdog662]

Stay away from 304 SS as baffles though. It's machinability is very very low and work hardens if you do not know what you are doing. 304 is difficult to machine but is weldable.

I do hope your kidding

I just wanted to him to consider something I have experienced and that is 304 is harder to machine than 303 on a manual lathe. If your tool dwell for a second you are going to work harden, 303 is much more forgiving in that area.

[Bowen1911]

I just wanted to him to consider something I have experienced and that is 304 is harder to machine than 303 on a manual lathe. If your tool dwell for a second you are going to work harden, 303 is much more forgiving in that area.

I use 304 for my baffle stack- It really isn't that hard to machine.

[Machine Gun Matt]

Stay away from 304 SS as baffles though. It's machinability is very very low and work hardens if you do not know what you are doing. 304 is difficult to machine but is weldable.

I do hope your kidding

I just wanted to him to consider something I have experienced and that is 304 is harder to machine than 303 on a manual lathe. If your tool dwell for a second you are going to work harden, 303 is much more forgiving in that area.

Better check your feeds,speeds,and cutting tools.

Are you using high speed steel cutters or carbide?

Coolant?

303 is not great (Ok it sucks) for muzzle brakes or rifle suppressors and will erode quickly.

IMHO, I wouldn't even consider using 303 for anything you want to last.

[redtazdog]

sharp tools, proper speed and feed make 304 and 316 easy

[Wicked]

sharp tools, proper speed and feed make 304 and 316 easy

And NOT using a mini-hobby-lathe. They're fine for materials like Al and CRS, but generally don't have enough ass for turning 304.
With a standard engine lathe, the additional power and rigidity will allow you to take a more substancial cut, so 304 will less likely work harden.

[fdv99]

The shop I work at has a high quality lathe, not a small hobby lathe or anything. I am confident in my machining abilities and the abilities of the lathe. I just wanted suggestions on material would work best.

Thanks