New Suppressor Design

[303Guy]

Yup, I've just built my best suppressor yet, taming a 243, making it sound like a suppressed 22rf high velocity. It's light and has few elements and is an over-barrel, keeping the length down so no shortening of the barrel is needed. Ummm.... I can't divulge the internal details because I want to market these things.

[Dan Cash]

Good for you! I wish it wern't illegal to build such in the U.S. as it seems real fun and a challenge.

[Doc_Stihl]

It's perfectly legal to build a suppressor in many states in the U.S.
You need to know the laws and fill out some paperwork. (BEFORE BUILDING IT).

[max range]

Well that is not a "tip or a trick" if you wont tell us how, now is it mate?

[303Guy]

Yep. I should've put this one under Special Projects. My bad. I was on a high after it's effectiveness and didn't consider what I was doing.

However, there is a tip involved and that is that taming the muzzle blast with a suppressor makes a rifle sooo sweet to shoot with. I stood next to the muzzle and there's nothing - just a 'spitt'. I just wish you folks could have it as good we do here down under.

There is a downside to the suppressor, it makes one forget the actual power of the rifle. We were shooting rabbits with later that evening with 100gr bullets! One could be tempted to burn up more powder and shoot off more bullets.

[contender1]

And shooting more is a PROBLEM????

[nanuk]

I really do NOT understand the opposition to a suppressor by gov'ts

seems if one was going to go to the trouble to use one for an illegal purpose, then one is going to do it without, anyways.

as for game shooting? I see no difference in the guys who shoot at 600 yds... game animals simple don't move after a shot at that distance unless you hit near the feet...

[DCM]

If I understand it correctly it is considered "poor etiquette" to hunt without one in many parts of Europe. They have more trouble getting firearms than suppressors.

[Te Hopo]

If I understand it correctly it is considered "poor etiquette" to hunt without one in many parts of Europe. They have more trouble getting firearms than suppressors.

It's not far off that here, my main hunting rifles are all suppressed as I hunt small game with .22lr's in rural areas often less than a half mile from the farm house or neighbors.
While with my centerfire, well I value what hearing I have left. :wink:

[machinisttx]

It's perfectly legal to build a suppressor in many states in the U.S.
You need to know the laws and fill out some paperwork. (BEFORE BUILDING IT).

Yep. $200 tax stamp, ATF form 1(application to make and register) or ATF form 4(application for transfer), plus a couple other things, and a couple months of waiting for ATF to approve and return the paperwork.

Machineguns, cannons, mortars, etc. are all also legal to own if you do the paperwork and pay the tax.


http://www.silencerco.com/?section=Education&page=Ownership

[wilit]

I really do NOT understand the opposition to a suppressor by gov'ts



I can't remember where I read it, but the supressor's inclusion in the 1934 NFA was more about preventing/reducing the cases of poaching of game animals. A lot of people don't know this tid-bit either, but handguns were very close to being included in this regulation. Thankfully they removed them from this silly piece of tax law.

[303Guy]

Well, the suppressor is definately increasing component sales. My buddy has taken to shooting rabbits and hares at long ranges with his rifle (short ranges too!) He just enjoys shooting it so much.:D He fired it about 50yds from me and I was astounded at how little noise it makes. Ther was a stand of biggish pines nearby and that's were most of the 'noise' came from. It's amazing. All my rifles are going to get one. Just wish you folks could get them easier.

[Artful]

Do you have access to a "good" db meter to do a standardized Mil-spec test of your design?

[303Guy]

No I don't. I was wondering about setting up some recording system and running it through the PC. That would only work for direct comparisons.

[Haggway]

Yep. $200 tax stamp, ATF form 1(application to make and register) or ATF form 4(application for transfer), plus a couple other things, and a couple months of waiting for ATF to approve and return the paperwork.

Machineguns, cannons, mortars, etc. are all also legal to own if you do the paperwork and pay the tax.


http://www.silencerco.com/?section=Education&page=Ownership

The wait is much longer now. It took me six months to get my last suppressor.
Now with that said, its was well worth it to be kind to my neighbor at the range to help protect our hearing, from our stupid days of not using ear plugs or ear muffs. Now we use all three.

[koehlerrk]

Lucky you, Haggway. Some of us live in states that won't let us put a muffler on a firearm...

[Artful]

Washington State just had their law changed so I think we are now up to 36 states that do - work on the legislature, they are supposed to represent your interests.

[Herb in Pa]

Pennsylvania doesn't have a problem with using them for hunting either...........

[Jacko.357]

Suppressors where legal in Australia, my Dad used them on his Model 62 Winchester's. I don't know when they where banned, sometime in the 1950's I think ??????

While Hollywood continues to make Movie's that feature supersonic loads in Rifles that go PFFFTTT when they are shot, the Australian authorities will pay no attention to the common sence approach taken by New Zealand.

I must admit though threaded muzzle's that accept "barrel tuning devices" are becoming more common now day's, imagine that !!!!!!!!!!!

Sounds interesting 303Guy, I enjoy your threads - you get me thinking, especially your capers with Lee Enfields

regards Jacko

[leadman]

There is a proposal here in Az to make suppressors legal for some hunting. Hope it goes thru.
I may have to look into making these myself as I am not in a position to buy a commercial model.

[wilit]

Lucky you, Haggway. Some of us live in states that won't let us put a muffler on a firearm...

I'm waiting for California to pass legislation requiring catalytic converters on our guns to cut down on the greenhouse emissions. :veryconfu

[Artful]

being CA is Assualt weapon restrictive, Hi-cap restrivie, 50 BMG restrictive, Suppressor restrictive, CCW restrictive, lead free ammo required for hunting.

I can see them requiring some other onerous regulation.

[303Guy]

Do any of the greenies and/or liberal folk who get this legislation passed happen to partake of substances we don't normally consider as suitable case fillers? That would be less harmful to ones health than .. err, well let's just say lead in the environment?:veryconfu

[wilit]

Do any of the greenies and/or liberal folk who get this legislation passed happen to partake of substances we don't normally consider as suitable case fillers? That would be less harmful to ones health than .. err, well let's just say lead in the environment?:veryconfu

Well, in CA you can get a prescription for medical grade marijuana for almost anything. So I wouldn't be surprised if some of these boneheads were heavily "medicated."

[303Guy]

Hang on. We could turn the tide on them. Think of this; a certain organic filler for cartridge loads with a little empty space that when fired smells a lot like burnt hedge clippings and is also green in the dried state. They'd quickly move to encourage reloading as a sport, probably pushing to make it a national sport! You gotta think outside the box.:veryconfu :mrgreen:

[Artful]

Green Boolits - I like it.

[DCM]

303Guy just came up with a new way to fund Castboolits! Scented ammo Copyright 2012!

A marketing ploy that I know many would go for if done right. I have heard many people complain about how bad certain powders smell. To me they all smell like victory.

[303Guy]

This new suppressor on my buddies 243 is causing an 'issue'. He just doesn't want to stop shooting bunnies with it! He enjoys the sound it makes so much - and so do I! :mrgreen:

[Cap'n Morgan]

This new suppressor on my buddies 243 is causing an 'issue'. He just doesn't want to stop shooting bunnies with it! He enjoys the sound it makes so much - and so do I! :mrgreen:

The nice thing about a suppressor is that you can clearly hear the >>thump<< when the bullet hits home. :drinks:

[Blue2]

I have a question for you people that are fortunite enough to be able to run suppressed rifles. When you are running supersonic and creating a sonic crack when the bullet passes through the air.---This sound is caused similar to thunder when the dispaced air implodes back into the vacuum caused by the bullet's travel.---The smaller the bullet diameter --the quieter the sonic crack. Now my question. - Would a high ballistic coeffecient bullet like a VLD boatail design be quieter than a round nose flat base bullet travelling the same supersonic speed?

[303Guy]

Blue2, it's not imploding that creates the supersonic crack, it's the compression shock wave at the nose of the boolit. A bigger bullet will make a bigger crack. Same for the shape of the bullet. The faster the bullet the less crack there is. That's because the time the crack is being created is shorter and of course the bullet moves away faster. A supersonic 22lr bullet sounds about the same as a 243 bullet.

http://i388.photobucket.com/albums/oo327/303Guy/bulnoise.gif

Not all suppressors are equal.

[Blue2]

So "303 Guy" Do I understand you correctly-- A sharp pointed bullet should be quieter than a blunter design ? Everything else being equal . A smaller tip would create a smaller shock wave?

[303Guy]

I don't know. I'd think the total frontal area would be part of the equation. In the test shown above the two bullet types seemed to produce the same sound level - spitzer versus hollow nose (or flat nose, don't know which).

[Artful]

Conventional bullet shapes don't make much difference, if you wanted to minimize the sonic crack you'd have to do something a little more radical like this shape.
http://www.acoustics.org/press/156th/Sparrow_clip_image002.jpg
A retractable, 24-foot-long retractable lance-like Quiet Spike, produced by Gulfstream Aerospace Corp., is mounted on the nose of a NASA Dryden's F-15B research aircraft. Combined with other technologies, that spike can create a significant reduction in the amplitude and annoyance of the sonic boom on the ground. [NASA photo by Tom Tschida].

[303Guy]

Artful, I was thinking of exactly that. But we can't do that with out boolits/bullets. So what exactly can we do? I haven't found any information on the shock-wave pressure levels of different bullet shapes or diameters. Maybe I just haven't looked hard enough.

[DrB]

I don't know. I'd think the total frontal area would be part of the equation. In the test shown above the two bullet types seemed to produce the same sound level - spitzer versus hollow nose (or flat nose, don't know which).

Congrats on the new suppresor! I've had a blast plunking squirrels with a suppressed contender this year. The loudest noise is the bullet hitting. Sounds like a bat on a wet sand bag. :)

I've got my paperwork done and am working on an integral design for a single shot 50AE rifle. I plan on launching 440 gr tc slugs with it... would love to discuss ideas with you somtime.

A few quick thoughts on bullet flight noise...

You will get an increase in flight noise before the bullet goes supersonic as the flow accelerates around the bullet and a shock will tend to form in the transonic flow (<m=1). Sears-hack bodies ("area ruled", long gradually tapered bodies) will tend to be quieter than blunt bodies. Smaller caliber sound pressure levels (spls) will drop off faster with distance from the shot than larger calibers.

The pressure profile associated with a supersonic bullet crack looks like an N. The leading shock passes and pressure jumps, then pressure drops from the expansion fan coming from the flow turning back in around the bullet body, then pressure jumps again from the trailing shock (which occurs from the flow rejoining behind the body meets itself.

Anyway, to summarize:
You want slower than just "subsonic" flight speed of bullet if you want something as quiet as possible

If supersonic, then:
More gradually tapered, skinny bullets are better (spitzer bt, not wc, rn, etc).
Noise at a given standoff is less for smaller calibers, everything else being equal


Shape is a relatively small effect as compared to mach number (velocity). If you want something quieter, the best option is to go subsonic. The next best is to go smaller caliber. Shape is a relatively small effect. As far as gas noise goes, it's also a lot easier to build an effective suppressor for a smaller caliber for a given suppresor diameter!

Best regards,
DrB

[Artful]

True DrB, Ideally you want 35 cal or smaller and 1050 fps or under with a blunt nose bullet to transfer maximum energy on impact. Supersonic you would want 35 cal or smaller, long heavy pointed bullet for good penetration with asymmetrical nose to promote tumbling inside target for maximum energy transfer on impact. Best to have efficient cartridge case design in either case to minimize airspace and amount of extra powder wasted to reach desired launch velocity.

[ridurall]

I've got several friends with suppressors and also those that are waiting on paperwork to go through. One of them is a bit over the 6 month part now. I've got a Winchester Model 61 .22 S, L, and LR pump rifle that is a sweet rifle to shoot. When I shoot shorts, it's as quiet as many of the suppressors of my friends. Oklahoma for the most part is great on their gun laws but they do not allow hunting with suppressed guns. That is too bad because OKlahoma as a rule is pretty smart with their gun laws except no hunting with suppressors, no open carry and no hunting with night vision scopes or infrared scopes.

[Artful]

ridurall google up "cat sneeze" reloads - what you Winchester Model 61 does you can reload to do with other guns.

[ridurall]

Thanks, Artful I'll check it out.

[DrB]

True DrB, Ideally you want 35 cal or smaller and 1050 fps or under with a blunt nose bullet to transfer maximum energy on impact. Supersonic you would want 35 cal or smaller, long heavy pointed bullet for good penetration with asymmetrical nose to promote tumbling inside target for maximum energy transfer on impact. Best to have efficient cartridge case design in either case to minimize airspace and amount of extra powder wasted to reach desired launch velocity.

Artful, I've been flying the 7mm hunter of 30:1 pb:sn... I haven't shot anything bigger than fox squirrels with it yet. Penetration in packed wet sand was impressive at >11", with a ~.60" mushroom. I would guess it should exit on a broadside shot on our whitetail, unless a large bone is hit.

I do find the idea of a spoon nose interesting, but you would have to do it without radially offsetting the cg or you will "fling" the bullet at crown departure somewhat. May not impact accuracy too badly, but doesnt help! If you are going supersonic just a conventional expanding bullet design is gtg.

[Artful]

look up spooning the tip - ancient technique that seems to be making a comeback - but I would take a hard look at asymmetric the bullet nose.

Take a file and flatten one side to get bullet to yaw earlier in flesh wont impact flight in air much, should have very minor (hard to detect) impact on accuracy.

http://www.ja-galaxy-forum.com/board...r=28893&page=1

4.6x30mm H&K - H&K's answer to the 5.7x28mm FN. Based on HK's experimental 4.6x36mm cartridge for the HK36 ACR in the early '70s, even retaining its unique Löffelspitz (spoon-nose) projectile. Like the FN entry, the 4.6x30mm has amazing armor penetration, yet recoils less than a 9x19mm pistol cartridge. The smaller HK projectile appears to gives superior penetration over the FN variant, but this also detracts from the permanent wound cavity. Best against unarmored targets, but can be used against armored.
http://guns.connect.fi/gow/raloffel.jpg

extream exaggeration of the tip - you don't need that much - just a bit and be consistantly the same on each boolit.

In 1970s military applications of spoon nose bullet was vetoed International Committee of Red Cross, because Loeffelspitz bullets inflicted "at least as horrible wounds as explosive or Dum-Dum projectiles". Germans ceased development of 4.7 mm assault rifle and spoonpointed bullets. Russians designed about in the same time their 5.45 x 40 mm cartridge and bullet with terminal effect similar to German Loeffelspitz bullet, but they managed to hide "intrinsic asymmetricity" into the intact steel jacket by just putting air bubble in nose of bullet.

I'm looking thru a disc I got from a member here that has all the cast, swaging and paper patching articles put out by Handloader and Rifle magazine.

Specifically I'm looking at an Article by Wayne Blackwell which he entitled
"How Defects in Cast Bullets Affect Accuracy" - he has several tests with
one to a 30 caliber Lachmiller 311-175 FN with specifically created defects
and measures the resulting 6 shot groups (in inches)

No Measurable defect 1.05

Notched base______3.40

Notched nose______1.65

cold cast wrinkled___2.94

Drilled Base________7.70

Drilled side of nose__3.20

Mold off Spout Pour__2.53

Notice material taken as a notch in the point cause less dispersion in his test.

[DrB]

look up spooning the tip - ancient technique that seems to be making a comeback - but I would take a hard look at asymmetric the bullet nose.

Take a file and flatten one side to get bullet to yaw earlier in flesh wont impact flight in air much, should have very minor (hard to detect) impact on accuracy.

http://www.ja-galaxy-forum.com/board...r=28893&page=1

4.6x30mm H&K - H&K's answer to the 5.7x28mm FN. Based on HK's experimental 4.6x36mm cartridge for the HK36 ACR in the early '70s, even retaining its unique Löffelspitz (spoon-nose) projectile. Like the FN entry, the 4.6x30mm has amazing armor penetration, yet recoils less than a 9x19mm pistol cartridge. The smaller HK projectile appears to gives superior penetration over the FN variant, but this also detracts from the permanent wound cavity. Best against unarmored targets, but can be used against armored.
http://guns.connect.fi/gow/raloffel.jpg

extream exaggeration of the tip - you don't need that much - just a bit and be consistantly the same on each boolit.

In 1970s military applications of spoon nose bullet was vetoed International Committee of Red Cross, because Loeffelspitz bullets inflicted "at least as horrible wounds as explosive or Dum-Dum projectiles". Germans ceased development of 4.7 mm assault rifle and spoonpointed bullets. Russians designed about in the same time their 5.45 x 40 mm cartridge and bullet with terminal effect similar to German Loeffelspitz bullet, but they managed to hide "intrinsic asymmetricity" into the intact steel jacket by just putting air bubble in nose of bullet.

I'm looking thru a disc I got from a member here that has all the cast, swaging and paper patching articles put out by Handloader and Rifle magazine.

Specifically I'm looking at an Article by Wayne Blackwell which he entitled
"How Defects in Cast Bullets Affect Accuracy" - he has several tests with
one to a 30 caliber Lachmiller 311-175 FN with specifically created defects
and measures the resulting 6 shot groups (in inches)

No Measurable defect 1.05

Notched base______3.40

Notched nose______1.65

cold cast wrinkled___2.94

Drilled Base________7.70

Drilled side of nose__3.20

Mold off Spout Pour__2.53

Notice material taken as a notch in the point cause less dispersion in his test.

Yes, seen these data.... Perhaps the spooned nose digest was a prior post of yours, I think? Been awhile....

A defect in the nose is less a problem as the closer the defect is to centerline the less it offsets cg radially (and so less "fling" at crown. Also there is less perturbation than a base edge defect as you don't get the gas jet deflection at crown separation you can with base defects.

What I don't understand is why a spooned nose is preferable to a conventional expanding bullet design for supersonic applications? The latter is off the shelf and works just as well when suppressed at supersonic velocities. Subsonic I can just use dead soft lead with or without hp and high sd bullets to ensure penetration to/through vital organs?

Hk, etc, were motivated by enhancing lethality of fmj, trying to skirt the geneva convention prohibition of conventional expanding projectiles with something that looks like fmj.

[Artful]

Used by subsonic shooters mainly in bullets designed for HV so the jacket won't open up, the yawing/tumbling effect helps transfer energy for calibers where no projectile is designed to expand in the subsonic velocities.

[DLCTEX]

Texas is now considering allowing suppressors for hunting. We have responded to a poll to move this ruling forward.

[303Guy]

Texas is now considering allowing suppressors for hunting.That's great! I hope it goes through. Go Texas!

I went out with my buddy again today and he didn't even bother taking his rim fire - he just enjoys shooting that suppressed rifle so much. And it does have an appealing sound. Very appealing. The downside is he doesn't mind missing, just as long as he gets to shoot it! Mind you, he does come back with no rabbit and a big grin so that can't be all bad. He says to me, "Did you you hear that - it sounds so nice". It did sound nice.

I'm still to build one for a 308. That'll be the real test.

[leadman]

If the suppressors become legal for hunting here in Az I may contact you for the plans, if you decide to sell them.

[Idaho Sharpshooter]

303 Guy,

it's nice that you can own/build suppressors with less hassle than we can here in America.

Let the people here know how easy it is to own an AR-15 or AR-10(308W version), or four of them like I do here in Idaho.

There are tradeoffs where ever in the world you live.

[303Guy]

We can own semi-auto's too but there is a special category licence for owning pistol grip or large capacity magazines. I know someone who had or has a 50 BMG! (Not sure what he wants it for - just for the novelty I suppose). But we have to have a gun licence before we can have any guns at all, then it's up to how many we want. We have to sit a written exam for our licences. We can lose our licence if we do bad things. We are NOT allowed a defensive weapon of any kind and having a pistol is a pain and may only be carried to and from the range! Yup, there are trade-off's.

[ridurall]

Wow, 303 guy I thought you had it better than that. When I lived in Illinois I had to have a gun owners card and I didn't like that at all. Here in Oklahoma we don't have open carry but we have concealed carry must issue. The only other restriction is you can't carry anything 50 caliber or bigger concealed. (don't know anyone that needs to) but there are no restrictions on rifles and I know lot of 50 Cal owners include me.

[303Guy]

Well, I've accepted that a revolver in the bush as back-up is not going to happen. Then again we don't have a bunch of greenies trying to take away our rights. And really, we don't need to defend ourselves here. And I've never encountered someone who said "How can you kill such a beautiful animal". Our prime minister is a hunter too. We can hunt on in public reserves all year round. So all in all, we do have it pretty good. I'm happy anyway.

[ridurall]

For us having guns is not just about hunting it's about protecting ourselves, family and country from those that would do us harm or take our rights away. I do wish we didn't have to do so much paperwork for a supressor and I can't hunt with it here in Oklahoma. One would sure be handy while hunting prairie dogs. 303, you mentioned "revolver in the bush". That is the only place where I might no carry my .45. I normally carry it everywhere I go in public. I own a pest control company and I'm often not in the best part of town. It is nice to have when I'm not sure of those around me.

[FHinUK]

Hi

In the UK sound moderators are permitted, providing they are entered on your Firearms Licence, for each calibre - on Health & Safety grounds (minimise damage to hearing).

There are quite a few manufacturers now producing overbarrel and end types, with different thoughts on the baffle designs, materials to balance gas-cutting with lightness and longevity (minimising maintenance with corrosion from the acids formed by the gases mixing with condensation).

If you are interested in links to some of the information/manufacturers/internal detail available to us let me know and will post up.

Apart from reducing sound signature I find they do assist in attenuating perceived recoil (if this is a problem), maximise sight of the target and impact......down side is they do add weight so as to change balance and providing an extended ,snagging, option through woodland/cover etc.

[303Guy]

Welcome a board, FHinUK.:drinks:

I would indeed be interested those links, thanks.

My suppressor is pretty light. A early one I fitted to my slightly shortened barrel No.4 is no more than a muzzle break with suppressor qualities. It is actually a benefit in the bush and brush as it protects the muzzle from obstruction. I'm going to redo that one with my new baffle system and see how it works in a shorter form.

Something that surprised me regarding moisture, combustion acids and corrosion was that my pig gun with a full length non removable over-barrel suppressor had no corrosion on the exposed barrel inside it. (The baffle set was glued in with Loc-Tite and one day it got heated and shot the baffles out. The new one will screw in).

[TRM]

Interested please post links