Jacketed tube for 50 BMG?
Posted: Wed Nov 13, 2019 12:58 pm
I'm just gonna make this short and sweet. I'm looking to use a 2" od stainless tube with an aluminum jacket. Is it worth the time and paperwork or should I try something else?
Sound Suppressor Discussion
I do in fact have a 50bmg bolt gun. I have no knowledge on how to suppress a 50, and I assumed it would be like anything else, just bigger and made of steel. The Napa 4003 stainless tubes coupled together and freeze plugs seemed easier and cheaper. Keep in mind the Al would just be going over a functional can, mostly for heat dissipation.mr fixit wrote: ↑Wed Nov 13, 2019 4:29 pmI'm gonna answer short and sweet as well;
what you propose is not worth the time, effort,expense, and paperwork.
To elaborate, aluminum in centerfire is a bad idea. Freeze plugs are very much less than ideal as baffles (and I say this as the proud maker of a freeze plug can). Assuming you have a 50BMG rifle, you have well into 4 digits invested in the rifle. To add a $200 stamp to anything you build, it seems to me questionable why you would consider such a plan as you have laid out.
I want to do an over the barrel reflex type can, so a 12" tube would be the blast chamber over the barrel, and then I'd couple a 8"-12" tube on it for the baffles stack. I suspected this idea wouldn't be good, but I had my hopes.T-Rex wrote: ↑Wed Nov 13, 2019 5:10 pmIf you really want a 50BMG can, slow down and rethink.
2" will not be enough. I wouldn't go smaller than 2.5", unless you've made a couple and have experimented with designs.
A 50bmg having a chamber pressure equal to 55kpsi and a barrel length of 26"
Your muzzle pressure will be ~11kpsi or roughly equal to an 11" AR15
Add a 5" blast chamber (in a 2"ID tube) and you're blast chamber pressure drops to ~3kpsi
I wouldn't use any tubes coupled-together. Stacking tolerances, especially on long cylinders which need to be held concentric, should be respected.
Freeze plugs have been known to yield decent results, but that's when used in large numbers. 50BMG design rarely have more than 5 or 6 baffles. I don't see them being your answer, here.
What are your machining capabilities? Do you have access to machine tools or are you stuck using retail parts?
To you have friends that work at a machine shop or have one local to you?
I am a welder and I've done some machining, I just lack the equipment. Though, it probably would be a good idea to have someone else do the machining. I'm not sure what you mean by aimed slot.Capt. Link. wrote: ↑Wed Nov 13, 2019 10:51 pmTo succeed in your quest you will need to hire some machine time and a welder. I would suggest a 3x20" carbon tube and baffles.A 5.00 reflex using a two point mount will support it.Five to seven thick flat baffles plug welded into the tube will work well in this minimalist suppressor.These baffles should use a slanted sidewall plus a "special" aimed slot to enhance the performance without the extensive machining other baffles require.
I'm now retired from Pro work but suppressors for supersonic rounds was my niche, so I'm confident in what I suggest.
Oh, I'm listening. I'll modify what he told me to better suit my needs, like using chromoly (unless there's a reason I shouldn't) and I'll probably use inconel or 17-4 ss for the first baffle. I like his idea better than mine, and he seems to know what he's talking about. I'm here to learn!
Oh, like a keyhole. I have experience welding chromoly, so that's nothing new. But yeah, the baffle material will most likely depend on what time and willingness to learn a new material I have. What thickness would you recommend for the baffles? And how many spot welds would you recommend? I think I saw another thread on here where a guy used flat baffles and aluminum spacersCapt. Link. wrote: ↑Thu Nov 14, 2019 2:27 pmThe slot is a gas port used to increase turbulence between each baffle.Lot of good materials to choose from but the more exotic they are the more time and talent must be applied.Carbon steel is old school inexpensive and can be worked with basic tools plus can be caustic blued in a amateurs shop.
You must weigh the expense and time of building your own vs having it custom made by a experienced hand.I would suggest you consult with ECCO as he has the proper equipment and talent to do this job with ease using the latest technology in baffle design.A better baffle will also shrink the size and weight of this project.Just something to think about!
I don't plan on using aluminum internals, that's silly. I'm not welding together anything until I'm confident it won't blow up. I'll need practice machining, or just pay a guy to do the baffles for me. My plan for mounting is either a QD sleeve mount that goes over the barrel, or an internal tube welded at the rear of the can and welded in supports where it's threaded. My barrel is the same diameter for 12 on the end. I'm not sure which, if either, is a good idea, so I appreciate the feedback.Capt. Link. wrote: ↑Fri Nov 15, 2019 11:22 pmZero99z "Oh, like a keyhole. I have experience welding chromoly, so that's nothing new. But yeah, the baffle material will most likely depend on what time and willingness to learn a new material I have. What thickness would you recommend for the baffles? And how many spot welds would you recommend? I think I saw another thread on here where a guy used flat baffles and aluminum spacers"
I would choose a blast baffle material that can be hardened as the 50 will push the limits of any material.I'm not a welder but would think 6 or 8 plug welds per baffle would work.The thickness of the baffles root edge and the size of each plug weld must be large enough to support the pressures involved.Spacers are not needed in a welded design.
These baffles are not true flat baffles but are known as Thick Film Asymmetric type.Thickness of each baffle depends upon design and caliber.I normally used .250-.500" thickness for .308-.22LR depending on design.You will still need a lathe and milling machine to make even the most basic of these baffles plus the assembly and threading of the suppressor and modification of the barrel for a two point mount. I just wish you to be aware of the precision work required to build even a basic design.
that's not how heat dissipation works.Keep in mind the Al would just be going over a functional can, mostly for heat dissipation
Since aluminum sheds heat faster than steel I thought it might aid in heat dissipation. I've moved on from that idea and I'll just use chromoly for the tube.