Help silence your MFR, for under a quid!!

[kjud]

I was in a local trade supply shop last week looking through plumbing section when I noticed plastic reducers with dual O ring seals in two sizes, which looked to be perfect for the internal diameter of the MFR bull barrel and the ends are either internally or externally chamfered depending whether it accepts or recieves a fitting. I bought two of the large size (25p each) and Three of the small size (15p each).
Today I set about fitting these to the gun. The small item fits and 'locks' into the large one perfectly and the large one in turn fits the internal of the barrel sleeve. I am aware that to reduce esonance 'baffels and chambers need to be of varying sizes, so I took a look at how the still air device works in relation to the diffrent possibilities of the positions of the inserts. I decided to insert the small one into the larger one in 'opposing directions', (see Pic) would use the existing chamfer to channel the air blast outwards, and by cross drilling the larger external insert to would produce a space to catch the expanding air.
I did the same with the second insert but allowed this space to be much larger, absorbing more of the blast.
Due to the way these fitted together, the second small internal had to be shortned by about 10mm to allow the air to expand in the gap that was produced.
The final two mods included a rubber gromet (5p each, bought later), cut to correct external diameter to centralise the first baffel, and the 8mm off-cut used as a spacer to bridge the gap between the inserts and the still air decive.
I assembled everything with a wooden dowel along the bore-line to keep everything concentric, the plan was to use the natural 'give' of the inserts against the last two/ three turns of the end-cap still air device to hold everything together, centrally.
I assembled everything and took a few shots. The sound was slightly quieter, but only just, so i stripped everything out, and realised why. The original system works due to transferring the blast back along the shroud around the barrel, and my inserts were blocking these three ports, so I removed the O ring, and cut out three sections of the rear insert to match the original port. I replaced the O ring, positioned the inserts correctly and tried again. What can I say, Whisper quiet and no noticable extra weight (about 2 grams according to my VERY poor kitchen scales).
The whole job took twenty minutes and cost me 75p and I still have one of the inserts left over. Here are a few pictures (took with my mobile, so excuse the poor quality) I didn't photo the pieces with the three cut outs, but plan to and will post that image too.
I haven't been able to test accuracy yet, but there is nothing fouling the flight path, so hopefully everything should be Ok.

Individual Parts

Assembly

Bore line

[verminhunter]

Very good,but if anything go's wrong now you'll have to calla a plumber,nice one.

[Born Again]

Very good,but if anything go's wrong now you'll have to calla a plumber,nice one.

It's not the parts guvnor, it's the Labour see........s'gonna cost yer £50 for me to look at it.

[lateentry]

How did this work out in the end?

Did the gun still group? Any more pics.

Sounds fascinating. And a slight touch of Heath Robinson too.

[kjud]

I took the gun into the works unit today and set out a backstop at about 25yrds.
I put four mags through and apart from a four click adjustment at the start, there was no variation from normal. I was using a basic hand drawn cross and two circle targets. The grouping was very consistant with hole on hole shots
The last mag was plinking at plastic bottle tops nailed to the wooden backstop.
One in particular took four hits before all pieces were blown to bits!!
I'll not get the chance to field test at range for a week or two, but I'll keep everyone informed.
My digi camera is broken and when i get a new one, Ill take some better photos

Hope this helps,

Kev