Ive moderated my shotgun

[Ultrastu]

Looking down my barrel .id say the mossberg ones are about 4 mm and they are about 2.5 inch appart and opposite each other .

 

As far as subs are concerned .

At the muzzle you may notice a small reduction in sound . (Due to less powder in the cart so less blast )

But walk 30 yds away and I £ BET you can't tell the difference between a "sub " and a sonic .cart .

[lancer425]

Porting the barrel will shred plastic wads so heavy shot is out and the heavy pellets at subsonic would be good and essential for waterfowl.

How much difference will Porting make exactly?

[Ultrastu]

A lot .

[lancer425]

I am quite suprised at that the ports will let gasses into the moderator earlier on but they will reduce pressure as gasses go in to the moderator too.

Is it gasses in the moderator for longer sooner or is it reduced speed brought about by the porting and pressure loss, pressure is no guarantee of speed but when its porting involved that type of pressure reduction will loose speed i do not know how much as anyone and idea of the speed difference.

[sitsinhedges]

Any suggestions on port sizing?

I'm thinking 2mm ports 25.4mm apart

 

When I did mine I took measurements from a Hushpower. it had 5 pairs of 4mm holes drilled at 53mm centres starting at 240mm from the breech. Clean the inside of the barrel with a deburring tool when drilling. My outer tube was 16gauge aluminium.

Standard cartridges are noisier than subsonics even in a normal gun, you can stand at a clayground and know straight away when someone is using subs. You want a fibre cartridge with a small amount of fast powder so the gases don't overwhelm the moderator and fail to quieten it sufficiently. I've been loading superb 20gauge subs for years. Maybe a couple of boxes of clay trainer shells would be good to experiment with in this case.

Edited August 1, 2017 by sitsinhedges

[viking]

class mate, well done you

[Guest cookoff013]

This IS a great thread and I'm getting exactly what's needed loads of good sound ideas.

cookoff013 are you asking me?

Not in my gun yet......

Until I can get some kind of reliable noise reading on what I've done so far I'm not changing anything.

I'm more than happy to add baffles and port the barrel but I need to know what affect its having .

 

So let me get this right subs are a waste of time? Seriously?

But they sound so much quieter.

 

well, being as i have a subsonic proof program to manufacture multiple types of 12gauge subsonic ranging from 21g loads (thankyou *roughshooter *) all the way to the 42g loadings.

subs are not a waste of time but some "subsonic cartridges " are just that. subsonic means slow. now if you`d talk to us we could have told you there are 2 types of subsonics.

loud ones and quiet ones. its to do with the gas volume equilibrating to the outside atmosphere. the loud ones are when the powder isnt ideal and can be burning irratic.

 

what you need to understand is the internal ballistics involved when making subs not just going and reducing powder, with any load. subs are specific in they have a smaller amount of energy applied to them to get to the right speed.

the fast burning powders transmit there energy better by burning more complete, so grains in = energy out. even in limited amounts. theoretically if i add 18 grains of powder to a cartridge it creates 18grains of gas. we are not creating any weight, we are converting x grains of powder to x grains of gas, now, the issues surrounding the quietness is this, if you use a small amount of efficient powder it should produce more quiet subs because the gas has equilibrated. if the gas was in vast excess of the system it will saturate the system and cause what excess gas to exit the gun quite violently (as does all cartridges.)

 

when i created a fibre 1oz load i used the fastest powder i could find and 13odd grains got me there. resulting in quite quiet subsonics.

infact they are near identical to trainer loads, sadly i had to use the format of a 70mm and the wadding is rather large. but they perform beutiful.

 

sadly i havent got a hushpower.

 

from what i gather, even the 42g load with big shot hits game at distance, well thats reported from a few people.

[Twistedsanity]

Horses and noise are a funny thing. We had an old astra estate into which we fitted a jet engine with an afterburner on from a wasp helicopter, we were testing it on a friends farmland and using the afterburner and had to stop the test as the horses were so inquisitive they kept getting closer and we were fearful we would accidentally cook one

[Benthejockey]

My yard is next door to Haimwood shooting range and I can honestly say that even the most stupid neurotic horses get used to the bangs very quickly. The thing they hate the most is lamping even with NV they get a bit leary. Any way back then hush power...

[Daveo26]

Horses and noise are a funny thing. We had an old astra estate into which we fitted a jet engine with an afterburner on from a wasp helicopter, we were testing it on a friends farmland and using the afterburner and had to stop the test as the horses were so inquisitive they kept getting closer and we were fearful we would accidentally cook one

That post raisers far, far more questions than answers

[labstaff]

Horses and noise are a funny thing. We had an old astra estate into which we fitted a jet engine with an afterburner on from a wasp helicopter, we were testing it on a friends farmland and using the afterburner and had to stop the test as the horses were so inquisitive they kept getting closer and we were fearful we would accidentally cook one

That sounds incredible!!! This deserves a thread with pictures.

[Honey Monster]

Btw, It is llegal to make your own moderator for shotgun? No need of any registration on something? Any difference between making moderator for shotgun or for rifle?

[Daveo26]

Btw, It is llegal to make your own moderator for shotgun? No need of any registration on something? Any difference between making moderator for shotgun or for rifle?

Well if I was trying to sell them no doubt I'd have problems, but as I'm absolutely not even prepared to give anything away I'm confident I'm not doing anything illegal

A mod for a firearm is consider a component of a firearm once it's fitted and needs the relevant paperwork to make them but this is for a shotgun and it's purely for my own use

As far as I know I'm doing nothing wrong.

[DGrunt]

Howdy from across the pond. I noticed that there was a comment about semi auto's and the noise the functioning caused. I have a Gemtech Trek

that I use on a 10-22. To alleviate some of the noise from the functioning of the rifle, I purchased a Heavy Charging Handle. I do not believe you

would be able to order one, but this is a website in the States that has some. http://www.brownells.com/rifle-parts/bolt-parts/charging-handle-parts/charging-handles/ruger-10-22-17-rimfire-heavy-bolt-handle-prod23314.aspx. It is possible to also mill out a piece of aluminum or steel to attach to your current charging handle to help slow down some of the gases and allow

more gas to go through the silencer/moderator/can. If you hold the charging handle forward on a 10-22 while firing, you will notice a great deal of change in the

sound. (you would have to manually function it)Hope this information can assist.

 

[snarepeg]

Well if I was trying to sell them no doubt I'd have problems, but as I'm absolutely not even prepared to give anything away I'm confident I'm not doing anything illegal

A mod for a firearm is consider a component of a firearm once it's fitted and needs the relevant paperwork to make them but this is for a shotgun and it's purely for my own use

As far as I know I'm doing nothing wrong.

 

Have fully moderated a 410, holes in barrel. Etc.

Providing you keep it no proofing or registering required.

[Daveo26]

When I did mine I took measurements from a Hushpower. it had 5 pairs of 4mm holes drilled at 53mm centres starting at 240mm from the breech. Clean the inside of the barrel with a deburring tool when drilling. My outer tube was 16gauge aluminium.

Standard cartridges are noisier than subsonics even in a normal gun, you can stand at a clayground and know straight away when someone is using subs. You want a fibre cartridge with a small amount of fast powder so the gases don't overwhelm the moderator and fail to quieten it sufficiently. I've been loading superb 20gauge subs for years. Maybe a couple of boxes of clay trainer shells would be good to experiment with in this case.

Thanks for the info.

I think my tube is slightly thicker than that, good to know yours works.

 

I'm thinking about a new end cap that I would make coned shaped to divert the gases back into the can.

As the shot leaves the muzzle inside the mod the gasses expand in all directions, yes?

I'd leave a gap for the gas to fill, the shot travels through the hollow cone and the gases are interrupted and swirled round buy the cone shape.

I hope that makes sense.......

class mate, well done you

Thanks pal

[Daveo26]

Have fully moderated a 410, holes in barrel. Etc.

Providing you keep it no proofing or registering required.

Cheers for the reassurance.

[Ultrastu]

Yes that's the general idea .

The gasses tend to expand forward and side ways to a certain degree .the trickbis trying to get them to expand backwards into the tube .as you can appreciate a reflex mod (if there are no bleed hole in the rear .is a fixed volume of air and the gasses although at a much higher pressure will want to go out the muzzle end into the atmosphere instead of the reflex air ,as its easier .a couple of small (2.5 mm holes inbthe underside of the mod at the very rear will definately help the gasses expand backwards .

The best and most tried /effective way to slow the gasses forward momentum is the put baffles in the front section. But they need to be very strong to withstand the blast .

[Ultrastu]

Your idea of a cone at the front will work to a degree but a baffle stack of about 4 baffles 30 mm apart starting 2 inches from the actual muzzle will work best . (Or in conjunction )

Ps dont use any wadding in the mod as it will clog or possibly combust

[Daveo26]

Thanks

[Alpha Mule]

My yard is next door to Haimwood shooting range and I can honestly say that even the most stupid neurotic horses get used to the bangs very quickly. The thing they hate the most is lamping even with NV they get a bit leary. Any way back then hush power...

Agreed. Let them smellyou first then go to the far end of a field and let off a few roundd from HMR / centre fire and they get it. Go in with a moderated LR though and they fill their proverbials.

[Guest cookoff013]

Is there anything you would change or re_do again?

 

What I thought might be cool is to either add a rib on top with an adjusted, or mill a groove as a sighting plane.

 

Could the mod be off center so the body is lower and closer to the barrel top?.

 

This is a jolly thread.

[Honey Monster]

What is the outside diameter of moderator on .410 Baikal?

[snarepeg]

I moderated a Cooey single 410, used a damaged air arms tube, ground the forend out to allow it to go further back to the forend catch.

Bored 1/8 inch holes in barrel from about 10 inches from breech, fitted a couple of baffles at intervals to muzzle.

It is more like shooting a 12 GUAGE, the tube isn't as big in diameter and points well.

Use subsonic and it's reasonably quite.

[Remimax]

well, being as i have a subsonic proof program to manufacture multiple types of 12gauge subsonic ranging from 21g loads (thankyou *roughshooter *) all the way to the 42g loadings.

subs are not a waste of time but some "subsonic cartridges " are just that. subsonic means slow. now if you`d talk to us we could have told you there are 2 types of subsonics.

loud ones and quiet ones. its to do with the gas volume equilibrating to the outside atmosphere. the loud ones are when the powder isnt ideal and can be burning irratic.

 

what you need to understand is the internal ballistics involved when making subs not just going and reducing powder, with any load. subs are specific in they have a smaller amount of energy applied to them to get to the right speed.

the fast burning powders transmit there energy better by burning more complete, so grains in = energy out. even in limited amounts. theoretically if i add 18 grains of powder to a cartridge it creates 18grains of gas. we are not creating any weight, we are converting x grains of powder to x grains of gas, now, the issues surrounding the quietness is this, if you use a small amount of efficient powder it should produce more quiet subs because the gas has equilibrated. if the gas was in vast excess of the system it will saturate the system and cause what excess gas to exit the gun quite violently (as does all cartridges.)

 

when i created a fibre 1oz load i used the fastest powder i could find and 13odd grains got me there. resulting in quite quiet subsonics.

infact they are near identical to trainer loads, sadly i had to use the format of a 70mm and the wadding is rather large. but they perform beutiful.

 

sadly i havent got a hushpower.

 

from what i gather, even the 42g load with big shot hits game at distance, well thats reported from a few people.

been running some 70mm 20gauge 28gram 5s plastic wad ,13grains AS,8 star crimp chrono 1020 fps in my hushpower pump york guns.

fair reduction in noise with them over standard game loads.

Edited August 3, 2017 by Remimax