Jump to content

subsonic loads


Recommended Posts

I assumed you were talking about rimfire ammo. Shotgun subs i have never used so can't comment. When you ask a question it helps to elaborate exactly on what you are on about. In this case rifle or shotgun, it's better for you and better for anybody answering.

Link to comment
Share on other sites

If a gun fires a projectile that is less than about 1100fps you wont get the sonic crack as it travels thru the air. If you then use a barrel that has been ported along its length with an outer tube fitted too the expanding gases will exit into this void and also into the baffles forward of the muzzle of the barrel so there will be less of a sound wave coming from the gun too and so less noise. They can be very effective with the right gun and cartridges :good:

Link to comment
Share on other sites

So if I stick a subsonic cartridge through my bog standard O/U, will it be any quieter?!

 

 

Yes, it will be quieter than a conventional high velocity cartridge, for 2 simple reasons...

 

1. there is less/lower ignition powder so the propellant "bang" is quieter!

2. there cannot possibly be any suggestion of any sonic boom!

 

If by any chance you have some form of moderated shotgun it will be quieter still, as that will help to reduce the noise of the propellant ignition!

Edited by Dekers
Link to comment
Share on other sites

Guest cookoff013

So if I stick a subsonic cartridge through my bog standard O/U, will it be any quieter?!

 

maybe, the subsonic cartridges are marketed as a low noise cartridge anyway.

 

read my previous posts about loading subsonics.

 

if you are reloading buy hodgdon titewad, its better by far, load 32g of #5minimum or 4 optimal. then just shoot. choke wont matter at all, even shooting through cylinder will get a 3/4 pattern. then just shoot, may take some getting used to, but in the energy game,subs #4 is as good as #6 at 1500fps.

 

really i just like shooting them, use then in my light sxs, hits very hard, no recoil, patterns great and has some range. whats not to like?

Link to comment
Share on other sites

Guest cookoff013

To get the full benefit you need a moderated gun.

 

You will also find that with a moderated gun the porting causes a pressure drop that reduces the velocity of some standard ammo and so makes that pretty much subsonic too.

 

moderated guns can change the cartridge ballistics slightly. i actually dont own one, i`ve fired a few.

 

the problem some reloaders have, is they reduce the powder charge of an average cartridge, to make it subsonic. this can cause lots of problems. but in reality it causes just one, lack of pressure. no pressure causes dirty cartridges, poor shot to shot consistenctcy in both pressure and speed,

 

my next projects after some stuff i`ve got to finish, is subsonic 24g,28g and 36g. all will need different powders. (i mean a good recipe for the 28g load guys.)

Link to comment
Share on other sites

It is surprising how much of the bang of a shotgun is down to the pellet mass breaking the sound barrier on exit from the muzzle.

 

Until recently I had an old Damascus barreled hammer gun. Only used this sparingly and fired subsonics to keep pressure down.

Was using these up in the B325, very big difference in noise compared with 'standard' 1400 fps clay round. More of a thud than a bang,

much less high frequency sound.

 

A few figures to put this perspective, remembering of course that decibel is a logarithmic scale so a 10 dB increase means around 10X louder.

 

Standard clay shell : 150 dB

Subsonic clay shell : 70 dB

Best moderated 12ga : 45 dB

 

Conversational speech: 60/65 dB

 

As for their hunting effectivenes.

 

A UK legal 0.22 12 ft·lbf (16.2 J) air rifle fires a pellet at around 600 fps. Still adequate for some hunting purposes.

 

Speed of sound at sea level varies a bit because atmospheric changes but 1090 fps 740 mph is typical.

My subsonics quoted 1000 fps. 30+ g of 6 at that speed will still pack some clout.

Link to comment
Share on other sites

Guest cookoff013

It is surprising how much of the bang of a shotgun is down to the pellet mass breaking the sound barrier on exit from the muzzle.

Until recently I had an old Damascus barreled hammer gun. Only used this sparingly and fired subsonics to keep pressure down. Was using these up in the B325, very big difference in noise compared with 'standard' 1400 fps clay round. More of a thud than a bang,

much less high frequency sound.

A few figures to put this perspective, remembering of course that decibel is a logarithmic scale so a 10 dB increase means around 10X louder.

Standard clay shell : 150 dB

Subsonic clay shell : 70 dB

Best moderated 12ga : 45 dB

Conversational speech: 60/65 dB

As for their hunting effectivenes.

A UK legal 0.22 12 ft·lbf (16.2 J) air rifle fires a pellet at around 600 fps. Still adequate for some hunting purposes.

Speed of sound at sea level varies a bit because atmospheric changes but 1090 fps 740 mph is typical.

My subsonics quoted 1000 fps. 30+ g of 6 at that speed will still pack some clout.

 

subsonics can be high pressure too. often they are even higher than normal, just to ensure the load actually moves. keeping the pressure up even for fast burning powders is hard when a limiting speed is added.

 

the fastest shotgun powders are used for 32g subsonic, going to a lower payload and the same powder charge can, shoot above subsonic speeds. reducing the powder charge again to ensure subsonic speeds just kills the load, it probly would cover the gun in unburnt powder.

 

if you are after "low" pressure loads, make them.

published recipes of subsonics have pressures of 10500psi. the 12gauge limit is 11500psi.

Link to comment
Share on other sites

I don't have much info about subsonics. I tried it with a 32 g specific powder so far. Simply reduced it about 0.2 gram. Don't know what was the pressure or velocity but there were almost no residue inside of barrel. For me, this look like it burned almost well. Also I am sure the pressure is lower than the pressure which given for hotter load recipe(0.2 gram more powder). For me again, this is a safe cartridge but maybe a bit slow :)

 

I know quick powders better for subsonic loads but it is more dangerous without a good recipe and exact application to me. Anyway, just my opinion. I am trying to learn. I need your opinion.

Link to comment
Share on other sites

  • 3 months later...

Interesting.....

I just found this load data, and wanted to revive this thread:

 

70mm Case.

CX2000 primer.

17grain Vectan AS

4mm Over Powder Card.

20mm Diana Fibre.

32gm #4 lead shot.

Star crimp.

Its listed as being 940fps (@ 2.5mtr) 402 bar. 5830PSI?

 

I have been loading a similar load but I use 16 grains of Vectan AS with 28grams of shot.... and have to add a 3mm fibre slice to pad it out.

 

Is 32 grams with AS not too much?? Has anyone got any experience of this load? or know of its source?

Edited by aliengravy
Link to comment
Share on other sites

Guest cookoff013

my recomendation is to use 18grains of AS in the above recipe.

 

that 32g load is very easy to load, performs very well. i`ve fired well over 1000 rounds and i do recomend 4s for hunting applications. it was from m2m /folkeston engineer

 

as you can see the pressure of that load is very anaemic. but it is usable. infact the same data exists here...

 

www.domesticshotgunreloading.co.uk

http://www.metal2models.btinternet.co.uk/loads1.htm

Edited by cookoff013
Link to comment
Share on other sites

 

I have been loading a similar load but I use 16 grains of Vectan AS with 28grams of shot.... and have to add a 3mm fibre slice to pad it out.

 

I think you need a chrono. Let's assume that your load project(28g) has at least 940 fps and amount of unburnt powder approx. the same as above recipe(32g) then we may assume that 28g recipe as usable as the other one(32g). By the way 940 fps and 402 bar recipe is not looking like a safe recipe to me. I'm afraid may lead a stuck wad in barrel. Especially in cold weathers.

 

Meanwhile I wish a "safe recipes" thread here.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...