Si Brown carbon fibre silencers

[Jonjon79 13,340]

As most of you are probably aware by now, our very own Si Brown has been developing and making his own carbon fibre silencers.

 ........ I understand that it's still early days and, there are a lot of ideas in the pipeline and, testing still to come.

 

Just from speaking to Si, it's clear that he's got a real passion for the engineering side of air guns.

 ....... So much so that I hear he's got a pillar drill and lathe set up in his dining room

 

Si very kindly sent me a couple to try - the first one, which I'll call the Mk1, arrived over a month ago. The second one, the Mk2 arrived last week.

 ....... Thank you mate

 

Today is the first chance I've had to put them them through their paces - I got to work nice and early so that I could have a clear 30yrds indoors.

Now, I don't have a sound meter and, the apps that I found were all shite but, the sound does come back rather well in this warehouse so, all of the opinions on noise reduction are taken with my very own ear hole.

 

Si might not thank me for this but, I put his silencers up against some very well regarded makes today

 

Here's a brief spec' of each..........

 

A&M Marksman - 225mm x 38mm

4 internal chambers

8mm exit hole

 

Hogan Decimeater - 180mm x 30mm

3 internal chambers

9mm exit hole

 

Weihrauch silencer - 191mm x 29mm

3 internal chambers

8mm exit hole

 

Si Brown Mk1 - 139mm x 28mm

1 single internal chamber

8mm exit hole

 

Si Brown Mk2 - 181mm x 30mm

3 internal chambers

7mm exit hole

 

The rifles used for the test were the TX200hc and the HW100, both .177

[walshie 2,804]

If I could ask a technical question here. Obviously all the manufacturers know what they are doing, but why is the exit hole so big in relation to the calibre? 7, 8 and 9mm for a 4.5mm pellet seems to be very large - in the biggest case twice the size of the pellet.

For instance, on a powder burner, a 7.5mm hole is used for a 6mm projectile. An 8.5mm hole is used for .30cal (7.62mm). Obviously all makes are slightly different ,but this is about the norm.

Or is it something to do with air pressure in an airgun?

[bigmac 97kt 13,732]

Jon the one i have is as good if not better than the hw mod

what did you think of the mod on the hw100

this man is going places in the air gun world

next he will have his own stall at the air gun show

atvbjimmy

[bigmac 97kt 13,732]

3 minutes ago, walshie said:

If I could ask a technical question here. Obviously all the manufacturers know what they are doing, but why is the exit hole so big in relation to the calibre? 7, 8 and 9mm for a 4.5mm pellet seems to be very large - in the biggest case twice the size of the pellet.

For instance, on a powder burner, a 7.5mm hole is used for a 6mm projectile. An 8.5mm hole is used for .30cal (7.62mm). Obviously all makes are slightly different ,but this is about the norm.

Or is it something to do with air pressure in an airgun?

Iv often thought that my self Dave

good question very good question in deed

atvbjimmy

[Jonjon79 13,340]

Fist up was the Si Brown Mk1.

...... This was made to be a compact silencer for the TX and, I believe, was one of Si's very first.

 

I did 3 x 10 shot groups with Falcon Accuracy Plus pellets.

 

First, with just the standard plenum insert - I've found with this, I do have to concentrate more on my hold and build the shot properly for good accuracy.

Although the TX does have a sound from it's internals working, like any springer, there is a report from the muzzle.

 

Next up was the Hogan Decimeater.

This really reduces the muzzle crack and, makes me realise that there really isn't much sound from the innards on this TX - the sound, even in this warehouse, is reduced to a dull thud.

However, it does tend to push the group low by around 1/4" at 30yrds.

But, the extra weight up front makes the rifle more stable and forgiving to shoot.

 

Lastly, we have the Si Brown Mk1.

This, for me, fits well with my set up - it's slim and compact and, the carbon fibre and ally colours go well with the additions from Rowan Engineering.

 

For noise suppression, it's a very close second to the Decimeater - because of it's size, that did surprise me.

It's a lot lighter than the Decimeater so, I do have to think about the shot a little more but, it still makes the TX easier to shoot.

 ...... If anything, I think the single chamber is kind of acting like a muzzle break as well as a silencer.

 

I've tried a few silencers on this TX and, they've all pushed my groups low - this silencer actually pushed my group high by 1/4" to 1/2" at 30yrds

...... For a walk round the woods with the TX, I reckon this little silencer could be my new best friend.

 

 

Next up was the Si Brown Mk2.

 ....... For this, I used the HW100 .177 and, did 14 shot groups with JSB Heavy.

 

First up was the A&M Marksman - a big ol' silencer - the best I've ever used on a PCP.

In fact, it makes the HW100 sound like it's almost run out of air.

I've had this on the rifle for a while so it's zeroed with this set up.

....... I kind of used this for a benchmark for the next 3.

Probably not a fair comparison considering it's size and the amount of internal chambers but, go big or go home eh

 

Next up was the Hogan Decimeater and Weihrauch silencer - the performance from both was near identical.

Both reduced the PCP crack to perfectly acceptable levels for hunting.

Also, both pushed the groupings slightly high and right.

 

Now, the Si Brown Mk2.

....... Again, another surprise - this worked as well as the Decimeater and Weihrauch silencers but, has the benefit of being lighter.

Also, I think using a 7mm exit hole on a silencer of that length, with internal washers, was a brave move but, it worked and, it shows that the engineering is bang on

 

This one also pushed my group slightly high and a little the right.

 

I didn't rezero for any of the groups so, what you see in the pictures below is me aiming off slightly.

 

All in all, these are 2 shit hot silencers that have done well against some stiff competition today

 

I've no doubt at all that the groups would tighten up if I took the time to rezero both rifles to the silencers.

 

 

[Jonjon79 13,340]

Lastly, a couple of pictures of them on the rifles

 

Si knows I'm a bit of a Magpie so, mine have the posh ally end caps

 

In my honest opinion, they're sturdy, well made, good looking and, more importantly, effective.

 

Would I buy one?

 ........ Yes, without a doubt

 

Nice work indeed Si

........ If this is what you're producing now mate, I can't wait to see what you come up with in a couple of months time.

 

 

 

 

 

 

 

 

 

 

 

 

 

Ps, you're not having these back, I'm keeping them

 

Atb mate.

[villaman 9,979]

Quote

 

 They Defiantly sounds good  , perhaps Si should give up brick laying and start airgun repairs

Specially after seeing his brick wall on one of Si post   

[villaman 9,979]

Just now, Jonjon79 said:

Lastly, a couple of pictures of them on the rifles

 

Si knows I'm a bit of a Magpie so, mine have the posh ally end caps

 

In my honest opinion, they're sturdy, well made, good looking and, more importantly, effective.

 

Would I buy one?

 ........ Yes, without a doubt

 

Nice work indeed Si

........ If this is what you're producing now mate, I can't wait to see what you come up with in a couple of months time.

 

 

 

 

 

 

 

 

 

 

 

 

 

Ps, you're not having these back, I'm keeping them

 

Atb mate.

They look the part and look expensive , makes the guns look good that's for sure 

[Jonjon79 13,340]

38 minutes ago, bigmac 97kt said:

Jon the one i have is as good if not better than the hw mod

what did you think of the mod on the hw100

this man is going places in the air gun world

next he will have his own stall at the air gun show

atvbjimmy

It's excellent mate - it's just done at least as well as a Hogan Decimeater and Weihrauch silencer

 

I agree mate - after shooting his 97 and trying out these silencers, he knows his stuff

[Jonjon79 13,340]

1 hour ago, walshie said:

If I could ask a technical question here. Obviously all the manufacturers know what they are doing, but why is the exit hole so big in relation to the calibre? 7, 8 and 9mm for a 4.5mm pellet seems to be very large - in the biggest case twice the size of the pellet.

For instance, on a powder burner, a 7.5mm hole is used for a 6mm projectile. An 8.5mm hole is used for .30cal (7.62mm). Obviously all makes are slightly different ,but this is about the norm.

Or is it something to do with air pressure in an airgun?

 

54 minutes ago, bigmac 97kt said:

Iv often thought that my self Dave

good question very good question in deed

atvbjimmy

I reckon because the regulations are less stringent on airgun silencers and, there's less noise to silence, they can probably make them more universal and to lesser tolerances.

 

The Hogan Decimeater would probably work well right up to .25.

[Jonjon79 13,340]

24 minutes ago, villaman said:

They look the part and look expensive , makes the guns look good that's for sure 

He's done well with them mate

 

The pictures don't really do them justice - you can see how well made they are when you've got hold of them.

[bigmac 97kt 13,732]

1 hour ago, Jonjon79 said:

He's done well with them mate

 

The pictures don't really do them justice - you can see how well made they are when you've got hold of them.

Just got off the phone to si ordered a one the same length and width as a marksman but with the silver ends

and im going to have another made the same as i have but with the silver ends

they do look smart mind on your rifles Jon .

may even take the tx off sale and get him to make a brass end one

to match the brass bling on her lol

there is more to come Jon a lot more

and Mitch iv been saying that he needs to stop laying bricks and start this

THIS TIME NEXT YEAR

HE WILL OWN A BENTLEY OR A LAMBO LOL

atvbjimmy

[ArchieHood 3,692]

2 hours ago, walshie said:

If I could ask a technical question here. Obviously all the manufacturers know what they are doing, but why is the exit hole so big in relation to the calibre? 7, 8 and 9mm for a 4.5mm pellet seems to be very large - in the biggest case twice the size of the pellet.

For instance, on a powder burner, a 7.5mm hole is used for a 6mm projectile. An 8.5mm hole is used for .30cal (7.62mm). Obviously all makes are slightly different ,but this is about the norm.

Or is it something to do with air pressure in an airgun?

It depends how accurately you can get the outlet hole concentric with the bore of the barrel. The bore is not always exactly central, and most silencers fix to the outer circumference so there is a variable outside your control to begin with.

Then you have to think about how well the screw thread is cut if it's a 1/2 inch standard screw fit, is this cut exactly square and is the mount (barrel or adapter) also threaded exactly square? What about the shoulder the silencer tightens down to, is that flat and square and is there any paint to make the face uneven?

Ideally the hole should be the smallest you can get away with. A 22 cal pellet is 5.5mm diameter so a 6.5mm hole is a half a mil clearance all the way round. Get the concentricity out by half a mil and your pellets will clip..............

[walshie 2,804]

3 minutes ago, ArchieHood said:

It depends how accurately you can get the outlet hole concentric with the bore of the barrel. The bore is not always exactly central, and most silencers fix to the outer circumference so there is a variable outside your control to begin with.

Then you have to think about how well the screw thread is cut if it's a 1/2 inch standard screw fit, is this cut exactly square and is the mount (barrel or adapter) also threaded exactly square? What about the shoulder the silencer tightens down to, is that flat and square and is there any paint to make the face uneven?

Ideally the hole should be the smallest you can get away with. A 22 cal pellet is 5.5mm diameter so a 6.5mm hole is a half a mil clearance all the way round. Get the concentricity out by half a mil and your pellets will clip..............

I understand that, but surely that applies to any rifle, airgun to 50BMG. As stated above, a 30 cal/7.62mm moderator uses an 8.5mm hole which is even less clearance. 

[si brown 8,486]

Cheers for the kind words lads....exept you Mitch ?only kiddin!

this is basically a hobby as I’m a subby bricklayer and get rained off a lot. 

Archie hit the nail in the head with what he said? ...the smaller the exit hole the better but unless you’ve got access to seriously expensive kit you have to make the most of what you’ve got, the smaller ones to knock the edge off a springer or shrouded barrel don’t need as tighter exit as a standard  pcp and there’s less chance of them clipping..

where as the pcps need to be on the money at 7mm things have to be spot on and I’ve set up a jig to make sure things line up properly or pellets start flying all over, I could set them to 6mm but there’s no point risking clipping for the advantage gained!

Cheers lads? Si