Small supressor for full house 300BLK

[goodsteel]

Hello gents, thanks for approving my request to join.
My name is Tim Malcolm and I own Malcolm Ballistic Tool custom gunsmithing.
I don't say that as a plug, bit to explain that I'm a master machinist, and a professional gunsmith, so I have a good handle on the manufacturing side of things, and on supressor use in general.

I have an affinity for AR pistols. I love em. 300BLK and 7.62x39 are my favorite calibers, and 7" barrels are how I roll. I don't do subsonic, and I'm driving the socks off these cartridges. Obviously, this creates a fireball, recoil, and muzzle blast that will wake you up better than a double espresso.
What I want is a small supressor that will take the edge off. That's it. I want something less than 4.5" long, and less than 1.375 in diameter that will cut the decibel level down to 22 magnum rifle territory.

Is this possible?
Design tips? (1.5" blast tube with three K baffles? Cone baffles?)

Again, I'm not going for silence here but suppression. Just trying to mitigate muzzle blast, recoil, and report.
Thanks!!!!

[garredondojr]

I would like to start by saying I'm a nobody when it comes to suppressors lol. just been reading alot and have done 1 form 1 with 1 more to do.

that being said I would think given the confines of your design 1.375x4.5 I would try and maximize volume as much as possible. also being that your doing supers only I feel cones would be better than k's. possibly even omega baffles? (ask permission obviously) maybe do a smaller diameter cone. ie. .75-1" cone on a disc/cup the OD of the tube ID minus a few thou for clearance.

[T-Rex]

You're going to need a larger OD the shorter you go.
The brevis is 3.7in LG and 2in OD. It's rated for 5.56mm down to 7in bbl.
If I remember correctly, 300blk has only slightly lower muzzle pressure at this length.
Id figure flat baffles or cones. A blend of both with a possible coaxial design may be the ticket.

[Capt. Link.]

I have an affinity for AR pistols. I love em. 300BLK and 7.62x39 are my favorite calibers, and 7" barrels are how I roll. I don't do subsonic, and I'm driving the socks off these cartridges. Obviously, this creates a fireball, recoil, and muzzle blast that will wake you up better than a double espresso.
What I want is a small suppressor that will take the edge off. That's it. I want something less than 4.5" long, and less than 1.375 in diameter that will cut the decibel level down to 22 magnum rifle territory.

Is this possible?
Design tips? (1.5" blast tube with three K baffles? Cone baffles?)

You are asking allot from a tiny package unless you use ablatives and that would only work for a few shots. A dry suppressor of 3.00x4.500" will make a huge difference and may get you close to the objective. Using a coaxial design, a fair number of baffles can be used at the expense of erosion.Rotating baffles and limiting rapid fire will extend the lifespan of the device.
Design challenges are dealing with a large flame front.The faster the burning gases are extinguished the more effective the suppressor will be at lowering pressure the abbreviated length is a major obstacle to accomplishing this. If you are interested I have a modified coaxial cone design that has proven successful of FA 300blk and short barrels.
-CL

[T-Rex]

When the good Capt. offers his help, grab at it w/ both hands

Hey there CL. Hope all is well.

[ECCO Machine]

What I want is a small supressor that will take the edge off. That's it. I want something less than 4.5" long, and less than 1.375 in diameter that will cut the decibel level down to 22 magnum rifle territory.

Is this possible?
Design tips? (1.5" blast tube with three K baffles? Cone baffles?)

Again, I'm not going for silence here but suppression. Just trying to mitigate muzzle blast, recoil, and report.
Thanks!!!!

Yeah, it's probably possible, but a couple more inches would get you into hearing safe range. ".22 magnum rifle territory" is still pretty obnoxious at 140-ish dB, depending on barrel length. Is that little bit of extra length really worth still having to wear ears?

For minimum length, you want max diameter. If it has to fit inside a handguard, that's about 1-9/16". A 1-9/16 OD, .060" wall, 4.5" long with 2" blast chamber and 4 or 5 stepped cone baffles would be the first thing I'd try. I have a design that's only 6" long with 5 baffles and hearing safe with M193 from short barrels, but it's husky; 1-13/16" OD.

[Capt. Link.]

When the good Capt. offers his help, grab at it w/ both hands

Hey there CL. Hope all is well.

A dream team of designers would be incomplete without T-Rex ..CL

Doing alright thanks bro.

OP:
I think getting to the spl level of a .22 mag will be very difficult using a over bore cartridge even @ 3.00" width.It still may be the best way to protect you from the concussive effects.

-CL

[fishman]

Have you considered reflex or integral designs?
Why do you have such a small diameter requirement?

If my goal was minimal added length and minimal weight, i'd do an integral with a ported barrel and 4-6 baffles in front of the muzzle. 1.5" tube. Probably all titanium.

[goodsteel]

Have you considered reflex or integral designs?
Why do you have such a small diameter requirement?

If my goal was minimal added length and minimal weight, i'd do an integral with a ported barrel and 4-6 baffles in front of the muzzle. 1.5" tube. Probably all titanium.

The MO of these pistols is short, light, handy, and minimalistic in every respect.
I'm using a handgaurd with an inside diameter of 1.350.

Again, the objective here is to take the edge off because it's absolutely hideous as is. I'm not going for silence at all. I just want to be able to take a few shots without permanent hearing damage, such as might be expected from any hunting rifle in the field.
However, if the length gets too much longer than what I've stated, there are other weapons that will find my hand faster. It's simply a matter of making the AR pistol more tempting to grab on my way out to the tractor/4wheeler/truck than any other weapon including the Rossi carbines etc etc etc.

My guns are working guns. It's not about "fun", it's about usefulness. Sure, I enjoy shooting, but my guns are there for a reason, and these AR pistols are one half assed suppressor shy of being the best thing since sliced bread for a grab and go general purpose farm gun.

[goodsteel]

You are asking allot from a tiny package unless you use ablatives and that would only work for a few shots. A dry suppressor of 3.00x4.500" will make a huge difference and may get you close to the objective. Using a coaxial design, a fair number of baffles can be used at the expense of erosion.Rotating baffles and limiting rapid fire will extend the lifespan of the device.
Design challenges are dealing with a large flame front.The faster the burning gases are extinguished the more effective the suppressor will be at lowering pressure the abbreviated length is a major obstacle to accomplishing this. If you are interested I have a modified coaxial cone design that has proven successful of FA 300blk and short barrels.
-CL

I am interested in your baffle design. I've never heard of "ablatives". I need something solid, light, and long lasting.

[a_canadian]

Ablatives are added liquids such as wire pulling gel or water, or white lithium grease, which serve to replace oxygen in minimizing first round pop (FRP) and to cool expanding combustion gases with steam/grease vapour between the baffles. Usually put into the blast chamber and first couple of baffle volumes after it. On really tiny suppressors such as a Wasp they are essential for reducing blast volume to hearing-safe levels or at least close to those. But since they cook off, they are limited to a handful of shots, typically one magazine or so before you need to inject more into the suppressor. With lithium grease one can unscrew the thing and inject more into the first section of the suppressor with a plastic glue syringe. With water just dipping in a bucket and tipping it around works. Wire pulling gel can be injected from a squeeze bottle from the front, angling the can upwards, but you don't want to get much into the barrel and action obviously.

Lithium grease is nicer than most ablatives as it also makes cleaning rimfire suppressors a lot easier. Provided it's renewed frequently, dismantling is easier, and cleaning the baffles becomes a matter of simple wiping with a paper towel. But if you shoot more than maybe 50 rounds of .22lr in a row, carbon and lead will start sticking to the first few baffles, making for more difficult cleaning. So not a very practical thing for those who like to dump huge numbers of shots at a time. More of a bolt action and hunting sort of thing.

[ECCO Machine]

I'm using a handgaurd with an inside diameter of 1.350.

Best of luck, man. I'll stop short of saying it's impossible, but dropping the report of supersonic rifle cartridges from very short barrels by 15-20 dB with a 1-5/16 OD x 4-1/2" long can is a very tall order. I've made a couple prototype cans that size, and they barely get .380 or subsonic 9 into the high 130s running dry. The Omega 9K is a very mature can, and 9mm subs still snap me a little out of that one, which is slightly fatter and longer than your max dimension requirement.

[goodsteel]

I'm using a handgaurd with an inside diameter of 1.350.

Best of luck, man. I'll stop short of saying it's impossible, but dropping the report of supersonic rifle cartridges from very short barrels by 15-20 dB with a 1-5/16 OD x 4-1/2" long can is a very tall order. I've made a couple prototype cans that size, and they barely get .380 or subsonic 9 into the high 130s running dry. The Omega 9K is a very mature can, and 9mm subs still snap me a little out of that one, which is slightly fatter and longer than your max dimension requirement.

I get the feeling you're the type that needs "hearing safe" from a suppressor. That's not what I need at all. I heard of a feller that went hunting with a 30-06 and didn't take hearing protection with him. He's shot a lot of deer that way too. He pretends like his hearing damage is minimal, but I'm sure he secretly battles tinnitus. I'm not saying I'm going to go crazy like that dude, but I'd like to live a little on the dangerous side of suppressed fire.
And hay, if it does what I need and doesn't qualify as a suppressor, then I save $200!!!
LOL!!!!!

[T-Rex]

If you really just want a minimal design with less than exemplary results, your proposed size could do what your asking. It will absolutely fall into the purview of the NFA (even the slightest noise reduction qualifies as a silencer)

With a 7" barrel, you're going to want a muzzle device as a sacrificial baffle. This can be used as your mount point and be a non-NFA part. It will wear, from the short barrel, and can legally be replaced by a non-licensee. After that, you're getting 2, maybe 3, baffles in there. The Valve Spring Retainer profile or Rusty's RSC design might be best. Personally, I'd weld the thing shut. Less machine work and your not going to need a reason to get back inside.

[ECCO Machine]

I get the feeling you're the type that needs "hearing safe" from a suppressor.

Ummm, yeah.........what's the point if I still have to wear ear pro?

And hay, if it does what I need and doesn't qualify as a suppressor, then I save $200!!!
LOL!!!!!

Anything more than a flash can with a single cone like the Noveske KX3/KX5 is going to be a silencer under the law. Even those would be if they had an end cap in addition to the one cone.

The term “Firearm Silencer” or “Firearm Muffler” means any device for silencing, muffling, or diminishing the report of a portable firearm, including any combination of parts, designed or redesigned, and intended for the use in assembling or fabricating a firearm silencer or firearm muffler, any part intended only for use in such assembly or fabrication.

[Obiwanbonjovi]

4.5" long, or 4.5" added length? Thats not much volume to work with, would certainly be very helpful if tou could add length over the barrel to add volume, also could help a ton by stepping up the diameter out front past the handguards, nothing says the od has to be constant.

[Elkins45]

I would trim those hand guards back to make room for a longer can, and consider a reflex design to get some extra volume.