Modified FX Moderator (the empty tube)

[FelixS]

I mistakenly left a modified FX moderator on a gun sale and since it worked so well, I thought I would do it again.

I then thought I would share what I did for those interested.

HOME MADE MODERATOR USING HOLLOW FX TUBE

PARTS:

FX MODERATOR TUBE

PVC PIPE

EMPTY WATER BOTTLE

STAINLESS WINDOW SCREEN

FELT



METHOD

USE A HOLLOW FX MODERATOR TUBE (TUBE)

BARREL END EXIT END

NOTE THE INTERNAL CONICAL STRUCTURE AT THE BARREL END

CUT THE TOP OFF A THICK PLASTIC WATER BOTTLE TO USE AS A CENTERING DEVICE (CD)

THE SHOULDER MUST BE CUT TO MATCH THE INSIDE OF THE EXIT END OF THE TUBE CAP

CD OPENING END SIZE MATCHES INSIDE OF TUBE



FIND A PVC PIPE (PIPE) THAT FITS SNUGLY INTO THE CD OPENING END (SHIM WITH TAPE IF NEEDED)

THE PIPE SHOULD BE SLIGHTLY LONGER THAN THE TUBE

PLACE THE PIPE INTO THE TUBE FROM THE EXIT END

THE PIPE WILL SELF CENTER DUE TO THE CONICAL SHAPE AT THE INSIDE OF THE BARREL END

CAREFULLY MEASURE THE PIPE TO FIT SNUGLY TO THE EXIT END ONCE THE END IS SCREWED BACK ON

CUT THE PIPE AS MEASURED, PLACE THE CD INSIDE THE TUBE SO THAT THE SHOULDER FACES THE EXIT

TEST FIT THE PIPE BY PLACING IT BACK INSIDE THE TUBE AND SCREWING ON THE CAP

REMOVE THE PIPE

AT 12 O’CLOCK, MARK THE PIPE AT 3/4” INTERVALS, DRILL THROUGH 3/8” HOLES AT MARKS

AT 3 0’CLOCK, STAGGER, MEASURE, AND MARK THE PIPE AS ABOVE, DRILL HOLES THROUGH, ETC.

YOU CAN ADJUST THE HOLE SPREAD, DIAMETER, AND NUMBER AS YOU SEE FIT

CLEAN DRILLING DEBRIS INSIDE AND OUTSIDE THE PIPE WITH SANDPAPER

CUT STAINLESS STEEL WINDOW SCREEN TO LENGTH FROM BARREL END TO WHERE THE DRILLED PIPE MEETS THE CD OPENING END, AND WIDE ENOUGH TO WRAP THE DRILLED PIPE, WITH ½” OVERLAP

THEN, USE A PIPE OR DOWEL THAT IS OF SMALLER DIAMETER THAN THE DRILLED PIPE TO SHAPE THE SCREEN, THEN WRAP IT. DOING SO WILL HELP THE SCREEN SELF CLING

WRAP THE PIPE IN FELT (BEFORE CUTTING) AND TEST FIT TO SEE HOW MANY WRAPS IT WILL TAKE TO GET IT TO FIT SNUGLY INTO THE TUBE. IT SHOULD BE SLIGHTLY SNUG, BUT NOT TIGHT!

CUT THE FELT THE SAME LENGTH AS THE SCREEN AND AS WIDE AS DETERMINED BY THE TEST FIT

WRAP THE FELT AND INSERT IT IN THE TUBE (OPTIONAL TO GLUE FELT EDGE) SCREW IT TOGETHER.

ASSEMBLY WITHOUT THE SCREEN AND FELT WRAPPING FOR VISIBILITY

I USED THIS ON MY .25 BOBCAT AND IT WAS QUIETER THAN A DFL SUMO

 

[Jack.K]

I went with a similar approach using a 3D printer. 

 

[qball]

I tried wire mesh, nylon washers and felt, it’s actually noticeably better at lower power but at higher power the improvement isn’t as big so I use them on my lower powered pp700, 1720T and such. Non of them are above 12FPE and the DIY baffle/felt does lower the tone very noticeably. 

 

[FLgunner]

I 3D printed some baffles I downloaded from Thingiverse, just had to size them up a bit to fit. They work great!

 

[Long_Gun_Dallas]

 

That's a good design, Felix. Simple and effective.

These mods work super well when they're modified. Aluminum is great at absorbing vibration. And these are very sturdy as well as light. The exit has a cone baffle incorperated into the end cap as well, making it easy to sandwich a retaining cage there

Got a huma sound dampening cage and felt sandwiched in the tip of mine. I find putting dampening in the tip is about 85% as effective at attenuating frequency as filling the entire can. 

3d printed baffles from another member that used to make them