303, 304, or 416 stainless for machined baffle?

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skydiverMN

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I have a Grizzly G0769 (3/4 hp combo mill/lathe) and I'm creating some K baffles out of 1.5" 304 (it's just what I have). Yes, all legal hoops have been followed, Form 1 in hand. I use carbide inserts and can machine the outside and inside cones without too much difficulty, minus the long stringy spaghetti chips that are created. I've slowed down the speeds from what I've used on 12L14 and it's working okay. When I attempt to take too big of a cut, often the metal will fold over and just get pushed along as the cutting is taking place. Easy enough to see this and back off a bit. Cutoff and grooving in 304 (at least for me) is a nightmare and I often hangup my spindle where it stops and I have to quickly back off the cross slide or I'll blow a fuse. I've found that using a live center pushed into the cone offsets the lateral force of the cut off. Still it's a nasty business and I break quite a few of my inserts just pushing through one piece of stock.

Okay, so enough back story. I'm very new at all this, so I don't really know what I don't know. I am wondering if I'm wasting my time with 304 and could be better served with 303 or 416? I don't see myself getting anything heat treated, nor will I do any welding to any of the parts. My 12L14 R&D samples (without a through hole) began to rust pretty quickly after cleaning so I know that material is not reasonable for a (more-or-less) maintenance free baffle. Aluminum could be an option but, for this specific project, I'm sticking with steel.

I chopped my 1.5" 304 round stock into manageable pieces using an inexpensive Harbor Freight 14" abrasive wheel saw. Unfortunately, I do not have access to a metal bandsaw.

Couple Questions:
  1. Can I chop 416 stock into smaller pieces using my 14" abrasive saw, as I have done with 304?
  2. Would 303 be sufficient for my needs (machinability and corrosion resistance)? Another alloy?
What are your recommendations/thoughts? Thank you for your time!
 
Wouldn't use an abrasive cut off on anything to be machined. May be ok sometimes ,but with some materials it can make hard spots that won't machine well. I messed up a nice piece of 17-4 that way.
 
I have used 303 for suppressor baffles before and they work fine for me. It machines pretty easy and I have had no trouble with corrosion. I just made the first baffle thicker and use a brake mount so it can act as a sacrificial baffle as well. I have had it for 3ish years and put a few thousand rounds through it with no apparent erosion of the blast baffle.

I can't say for 416 though as I have not worked with it before.
 
I've read a lot about 17-4 being the preferred stainless for suppressors. but I don't yet know much beyond that. Out of curiosity, is the k baffle for a .22?
 
I would say try hss tooling instead of the carbide on the small lathe and 304. When I started out, I didn’t want to learn to grind hss at first, so I bought an ARWarner kit and it is great. Advantages of insert tooling in hss. I have turned loads of all types of SS with hss and a bit of Rigid dark threading oil as lube.

Also, one thing you won’t regret is buying one of the cheap 4x6 bandsaws. Throw the blade that comes with it away and buy a good name brand blade.
 
www.hobby-machinist.com

Tips For Dialing In And Indicating Tube With Steady Rest?

I need to thread a 1.5" 316 seamless tube on my PM 1030v lathe. I have done this kind of thing in the past with a HF 7x12 lathe but it was kind of a hack job and I wan't more precision now. I turned down a plug to put in the tube until it was a very tight fit. Then I stuck it in the 4 jaw...
www.hobby-machinist.com www.hobby-machinist.com

Check out the thread above.
What finish are you going to apply to the tube? What caliber? For center fire I would use 17-4 PH for the blast baffle. K baffles made of aluminum are sufficient for .22lr. If you're not a member yet join the forum on silencer talk.
 
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