Benjamin Muting the Marauder (How to make the quietest Marauder possible)

[Sdrawkcabnipyt]

My goal was simple: create the quietest possible .22 Marauder that still produces over 12 FPE for ethical gopher kills out to 40 yards. In other words, it had to be “backyard friendly” without sacrificing performance.

I chose the Benjamin Marauder as an upgrade to the Daisy 880, mostly because of its reputation for being one of the quietest affordable PCPs on the market. So when I pulled the trigger for the first time, I was shocked. The shot was loud, mechanical, and absolutely not backyard friendly. My stomach dropped.

Now, after a series of upgrades and experiments, this rifle is whisper quiet—quieter than a stock Marauder, yet still delivering the same energy. Here’s how I got there.


Original Setup

• Gun: Benjamin Marauder .22 cal with Lothar Walther Barrel (unregulated)
• Pellets: JTS Dead Center 25.39 gr

Current Mods

• Hill Regulated Parts Kit
• Hill PEEK Striker
• Hill Barrel Band
• JSAR Twin Spring System (TSS) + Stopping Spring Guide (SSG)
• Huma XXL Regulator
• DonnyFL Sumo Moderator
• Eagle Vision Harmonic Barrel Tuner with Air Stripper

Previous Mods

• Hill Depinger
• Airgun Revisions Tuned SSG
• Buck Rail Moderator

Component Breakdown and Reasoning

Moderator
I started with the Buck Rail 3D-printed moderator and later upgraded to the DonnyFL Sumo. Despite the price difference, I noticed no real change in shot report. Both are extremely effective at quieting the muzzle blast, but once that’s handled, mechanical noise becomes the dominant sound. A good moderator is essential, but only the beginning.


Regulator
Adding the Huma XXL regulator was a turning point. I experimented with pressures from 2200 to 1300 PSI. The lower the pressure holding the valve shut, the quieter the shot. Settling at 1300 PSI gave me the best balance. The depinger I tried earlier didn’t do much, but the regulator accomplished the same goal and more.


Hammer and SSG System
The JSAR TSS and SSG combo is easy to tune and doesn’t require disassembly. Compared to the AGR SSG I used before regulating, it’s much lighter and works better with the new valve dynamics. Preload settings on both hammer and SSG allow fine control over energy and dwell time.


Hill Regulated Parts Kit
This kit comes with a high-flow transfer port, aluminum hammer, dry-lube coating, drill bit for opening the barrel port, and an optional PEEK striker to reduce metal-on-metal impact. The changes are substantial enough that it’s hard to isolate which part had the biggest impact, but taken together, they deliver results.


Barrel Tuner
I haven’t tuned this yet, but the Eagle Vision unit with air stripper is installed. It likely helps with accuracy, especially at 40+ yards.


Tuning Profile

• Transfer Port: 100% open
• Striker: Fully seated (per PEEK instructions)
• Reg Pressure: 1300 PSI (90 bar)
• Hammer Preload: 100%
• SSG Preload: ~100%
• Spring: Factory (lightest available)

I found that once I went above 750 FPS, the noise started to climb sharply. After testing multiple configurations, I landed on one that allows full hammer preload (to retain power) and near-max SSG preload (to shorten dwell time). This combination is where the rifle runs the quietest.


Performance Results

• 25.39 gr @ 750 FPS ≈ 32 FPE
• Sound Meter: 66.8 dB at 36 inches to the side of the muzzle
• Accuracy: Sub-10 ES, reliable grouping at 40 yards

Final Thoughts and Next Steps

My current shot count isn’t great. I was getting over 60 shots from 3000 to 2000 PSI with just the AGR SSG unregulated. Now, I’m down to 40 regulated shots from 3000 to 1500psi. I suspect the issue is valve dwell and may try a lighter spring, though no airgun vendors seem to carry one softer than stock.

Another option could be the JSAR Delrin hammer, though it’s heavier and would probably require more reg pressure. I’ve also been eyeing the JSAR balanced valve, but it’s out of stock and I haven’t had luck getting a response from them.

There’s a video floating around of a fully JSAR-modded Marauder hitting mid-800s and still sounding quiet. Hard to judge sound through a video, but it’s got me thinking there may be more room to improve.

Accuracy is excellent. My 10-shot group at 40 yards honestly could’ve been tighter despite how good it was, but I’m still using a $25 CVLife scope from Amazon. Parallax is a mess, so that’s next on the list.

I’d love to hear about any of your experiences trying to quiet your air rifle down for backyard/silent shooting!

 

[Struckat]

Interesting.
I have the same gun. Hill depinger and the AGR SSG. Hitting a chipper with Hades @900, the impact is way louder than the gun.
Took me a while to get used to it. So quiet I wonder if something is wrong.
My lower powered guns are quieter though.

 

[6gun]

Mines an old gen 1 marauder 25 and I finally got it quiet. Mine required a de pinger, a tune around the least hammer travel and speed necessary, a shroud adapter for 1/2 unf and here's the tough part. Commercially I would recommend the donny yokozuna or Ryu since you can drop baffles to harmonic tune.

I tried a donny fx and a ronin and it didn't help the mrod much, even if they work great on my FX guns. I machined a little delrin collar to hold the shroud in the barrel band oring tighter to account for sag from muzzle weight and made my own small diameter mod with crude baffles out of plastics.

The new design of the yokozuna alone does as much as a ronin and shroud on a 70+fpe rifle. Perhaps the narrower, lighter Ryu could help the mrod too.

In the end it only shoots jsb kings, and even then only at 845 fps ,but it's sneaky now

I'm really dancing around what I did for a mod since they're quite standoffish about that here for the time being.

 

[joelayfield]

just glancing , your reg pressure should be closer to 1850 1900 psi , now your hammer will open and close faster , and if your looking for non massive power (16 gr pellet 900 fps. ) you probably would do better with " a lesser plenum " on your huma reg you'll probably have a better cycling reg per shot , "more consistent " shot to shot , how ever big plenum is good for big power and efficiency ! the worse thing you can do is have a valve with low pressure being hit with big hammer strikes ! the valve is open after the pellet has left the barrel "= low power . low efficiency and = loud also ! just by uping the reg pressure and backing off on the hammer you should be headed the right direction

 

[Motorhead]

Wayyyyyyy old tech ... by far not the first to figure it out, as we did so over 10 years ago !!!
Still lacking in a few parts & set up to be truly Very low noise w/o need for an external LDC

Nice go at it tho as it seems to be doing quite well

Hill copied and marketed parts and pieces designed many years ago shared openly on the Marauder forum and GTA forum for self tuners/doers. Not a dig, just the truth of the matter.

 

[boscoebrea]

I have the same rifle,my music is louder,

 

[Sdrawkcabnipyt]

Interesting.
I have the same gun. Hill depinger and the AGR SSG. Hitting a chipper with Hades @900, the impact is way louder than the gun.
Took me a while to get used to it. So quiet I wonder if something is wrong.
My lower powered guns are quieter though.

Haha yeh I was expecting something much quieter at first! I felt like my depinger more just changed the tone of the ping rather than getting rid of it. But I really think most the noise is in the valve.

 

[Sdrawkcabnipyt]

I have the same rifle,my music is louder,

Louder than it stock? You play some darn loud music if that’s the case haha

 

[Sdrawkcabnipyt]

Wayyyyyyy old tech ... by far not the first to figure it out, as we did so over 10 years ago !!!
Still lacking in a few parts & set up to be truly Very low noise w/o need for an external LDC

Nice go at it tho as it seems to be doing quite well

Hill copied and marketed parts and pieces designed many years ago shared openly on the Marauder forum and GTA forum for self tuners/doers. Not a dig, just the truth of the matter.

I didn’t know that, interesting back story. I guess he filled a void for the people that like to tune but don’t know how to make the stuff diy. I actually feel like regulated parts kit is really just paying for the valve and hammer and the rest is just kind of filler. I already had the drill bit they offered. O rings and dry lube aren’t really anything special. Hindsight I would have just got the HFTP, drilled out then inlet port myself, maybe got the hammer with the PEEK striker. I could be wrong but I have an unjustified feeling then JSAR balanced valve will be better performance. I’ll never know if they don’t restock it though..

 

[Sdrawkcabnipyt]

just glancing , your reg pressure should be closer to 1850 1900 psi , now your hammer will open and close faster , and if your looking for non massive power (16 gr pellet 900 fps. ) you probably would do better with " a lesser plenum " on your huma reg you'll probably have a better cycling reg per shot , "more consistent " shot to shot , how ever big plenum is good for big power and efficiency ! the worse thing you can do is have a valve with low pressure being hit with big hammer strikes ! the valve is open after the pellet has left the barrel "= low power . low efficiency and = loud also ! just by uping the reg pressure and backing off on the hammer you should be headed the right direction

You’re right about the big hammer strikes being a problem. My issue was at 1850 psi the sound is super loud still. I tried at 2200, 1800, 1500, and 1300. By far the quietest(which is my main concern) is the low 1300. For this reason I’m looking for a weaker hammer spring I can replace. Lower force on the valve should open it less and allow it to close faster.

I think you’re 100% right about shot count and the smaller huma plenum. The only reason I chose the XXL was because I had the thought that more air capacity would maybe allow me to open then valve less (less force and sound).

Regardless a good tune should get a better shot cycle than what I am getting, considering the full capacity unregulated was able to get much better than that. Albeit different parts.

Thanks for your input! The huma plenum size has crossed my mind multiple times. I was thinking about emailing to see if I can just buy the plenum attachment as it just screws on to the regulator pressure valve.

 

[Sdrawkcabnipyt]

Mines an old gen 1 marauder 25 and I finally got it quiet. Mine required a de pinger, a tune around the least hammer travel and speed necessary, a shroud adapter for 1/2 unf and here's the tough part. Commercially I would recommend the donny yokozuna or Ryu since you can drop baffles to harmonic tune.

I tried a donny fx and a ronin and it didn't help the mrod much, even if they work great on my FX guns. I machined a little delrin collar to hold the shroud in the barrel band oring tighter to account for sag from muzzle weight and made my own small diameter mod with crude baffles out of plastics.

The new design of the yokozuna alone does as much as a ronin and shroud on a 70+fpe rifle. Perhaps the narrower, lighter Ryu could help the mrod too.

In the end it only shoots jsb kings, and even then only at 845 fps ,but it's sneaky now

I'm really dancing around what I did for a mod since they're quite standoffish about that here for the time being.

I know what you’re talking about and it sounds like possibly laws may change on that subject soon, maybe we will be able to talk more on it in the future.

Beyond moderation though, don’t you have a very loud mechanical hit of hammer on valve still? Or did you find a way to quiet that? Are you using an SSG or TSS or HDD?

 

[6gun]

I know what you’re talking about and it sounds like possibly laws may change on that subject soon, maybe we will be able to talk more on it in the future.

Beyond moderation though, don’t you have a very loud mechanical hit of hammer on valve still? Or did you find a way to quiet that? Are you using an SSG or TSS or HDD?

I'm using only a depinger and a tune to lessen the hammer stroke and velocity because I could never get the old ball bearing hdd to be quiet. It took me 10 or 12 years to tune it down and even then it's an extremely limited gun in 25. I figure my neighbors can figure out what a poof sound is from but a click is more ambiguous.

 

[joelayfield]

I didn’t know that, interesting back story. I guess he filled a void for the people that like to tune but don’t know how to make the stuff diy. I actually feel like regulated parts kit is really just paying for the valve and hammer and the rest is just kind of filler. I already had the drill bit they offered. O rings and dry lube aren’t really anything special. Hindsight I would have just got the HFTP, drilled out then inlet port myself, maybe got the hammer with the PEEK striker. I could be wrong but I have an unjustified feeling then JSAR balanced valve will be better performance. I’ll never know if they don’t restock it though..

id stay away from those JSAR valves , ive had stiction problems and leaks , over 5 try's ! other parts they have are really nice ,

 

[rcarlisle]

One of the things that really quieted down my Marauder was to drill out the plastic air stripper inside the shroud such that the holes are larger and biased to direct air back into the shroud. I have a Gen 1 .177 Mrod that is very quiet, wimpy sounding even. Yet it is slinging 10.3gr pellets ~880 FPS. Without a doubt, the pellet impact is louder than the shot and way louder when there's a critter involved.

 

[AlanMcD]

I find the nylon hammers to be quieter than the metal ones, but JSAR's will be too heavy for your use at that low a regulated pressure (they run about 34 grams or so - heavier than the Hill hammer). In truth, even Hill's ~25 gram aluminum hammer is probably too heavy for a short dwell time on a 1300 psi regulator setting. People used to make custom weight nylon hammers back in the day when the Marauder was the hot ticket, but no so much anymore . . . I have not used Hill's stuff - I've only seen pictures online - but maybe you could drill out the vent holes in the hammer to lighten it up some. I'd want to get it under 20 grams for what you are doing, maybe even down to 15 grams or so.

Another path you could try would be to actually put a stiffer return spring in the valve - that should help counteract the hammer strike and shorten the dwell time. Almost nobody talks or thinks about doing that, but that is because most are going in the opposite direction you are (going for more power / higher pressures).

Honestly, I find the quietest operation at a given power level from well tuned guns tends to occur at higher pressures, not lower pressures. This is because the higher pressure air pulse can actually involve less total air release as the pellet accelerates faster on it with less total air released - the lower pressure pulse has to last longer. When you say the gun was louder at the higher regulated pressures, was the loudness from the muzzle blast or the mechanical action.

I have JSAR's balanced valve, and I do like the latest version. But at the low regulated pressures you are running it really does not offer you any advantages - you'd probably need an even lighter hammer to get the dwell down where you need it. The main benefit of a balanced valve is that they open with a lower striking force, and you really don't need that for what you are trying to accomplish - a "normal non-balanced valve" would be best in your case. I can tell you that my JSAR valve is in a Gen I .25 caliber shooting 25.4 grain pellets at ~910 FPS for about 47 FPE, regulated at 1900 psi, with a 36 gram hammer (with striker), BSTALEY buffer o-rings, and a transfer sleeve and barrel port of 0.185", uses the JSAR TSS/SSG, and it cocks effortlessley . The BSTALEY buffer is something you could try too with the Hill hammer you have, as it will help manage some of the excess hammer energy - I found better results in my .25 with the heavier hammer and the buffer than I did with either a 20 or 25 gram hammer without the buffer (and could not make the power I wanted with the lighter hammers with the buffer). You san search on here for more info on the method if you are interested.

Regulating the gun will always do more for reducing ping than any depinger will, although some of the depinger designs are better than others. Hopefully Huma will sell you a plain smaller plenum, although having a spare regulator is not a bad thing if they won't - they all need rebuilt every so often, and having one ready to go in a swap is nice to have on hand when you need it - then you can rebuild the other reg at your leisure.

 

[Sdrawkcabnipyt]

id stay away from those JSAR valves , ive had stiction problems and leaks , over 5 try's ! other parts they have are really nice ,

Was it the 2024model? They did a redesign of their parts a couple years back. The video I mentioned about the fully JSAR modded marauder was testing their new manufacturing. I also realized after the fact that it was most likely a lighter pellet though because he said it was 28FPE.

 

[Sdrawkcabnipyt]

One of the things that really quieted down my Marauder was to drill out the plastic air stripper inside the shroud such that the holes are larger and biased to direct air back into the shroud. I have a Gen 1 .177 Mrod that is very quiet, wimpy sounding even. Yet it is slinging 10.3gr pellets ~880 FPS. Without a doubt, the pellet impact is louder than the shot and way louder when there's a critter involved.

I’m going to have to research this. But yeh it’s really not the air that I hear at this point. Just mechanical noise. Are you saying basically the holes are drilled bigger on one side of the air stripper? Like with a taper basically?

 

[Sdrawkcabnipyt]

I find the nylon hammers to be quieter than the metal ones, but JSAR's will be too heavy for your use at that low a regulated pressure (they run about 34 grams or so - heavier than the Hill hammer). In truth, even Hill's ~25 gram aluminum hammer is probably too heavy for a short dwell time on a 1300 psi regulator setting. People used to make custom weight nylon hammers back in the day when the Marauder was the hot ticket, but no so much anymore . . . I have not used Hill's stuff - I've only seen pictures online - but maybe you could drill out the vent holes in the hammer to lighten it up some. I'd want to get it under 20 grams for what you are doing, maybe even down to 15 grams or so.

Another path you could try would be to actually put a stiffer return spring in the valve - that should help counteract the hammer strike and shorten the dwell time. Almost nobody talks or thinks about doing that, but that is because most are going in the opposite direction you are (going for more power / higher pressures).

Honestly, I find the quietest operation at a given power level from well tuned guns tends to occur at higher pressures, not lower pressures. This is because the higher pressure air pulse can actually involve less total air release as the pellet accelerates faster on it with less total air released - the lower pressure pulse has to last longer. When you say the gun was louder at the higher regulated pressures, was the loudness from the muzzle blast or the mechanical action.

I have JSAR's balanced valve, and I do like the latest version. But at the low regulated pressures you are running it really does not offer you any advantages - you'd probably need an even lighter hammer to get the dwell down where you need it. The main benefit of a balanced valve is that they open with a lower striking force, and you really don't need that for what you are trying to accomplish - a "normal non-balanced valve" would be best in your case. I can tell you that my JSAR valve is in a Gen I .25 caliber shooting 25.4 grain pellets at ~910 FPS for about 47 FPE, regulated at 1900 psi, with a 36 gram hammer (with striker), BSTALEY buffer o-rings, and a transfer sleeve and barrel port of 0.185", uses the JSAR TSS/SSG, and it cocks effortlessley . The BSTALEY buffer is something you could try too with the Hill hammer you have, as it will help manage some of the excess hammer energy - I found better results in my .25 with the heavier hammer and the buffer than I did with either a 20 or 25 gram hammer without the buffer (and could not make the power I wanted with the lighter hammers with the buffer). You san search on here for more info on the method if you are interested.

Regulating the gun will always do more for reducing ping than any depinger will, although some of the depinger designs are better than others. Hopefully Huma will sell you a plain smaller plenum, although having a spare regulator is not a bad thing if they won't - they all need rebuilt every so often, and having one ready to go in a swap is nice to have on hand when you need it - then you can rebuild the other reg at your leisure.

I really like your drilling out the air holes idea to lighten the hammer. I suspected exactly what you’re saying about the derlin hammer, but if it really is an improvement than I can bump my reg pressure back up.

I will say, it’s always mechanical noise, I’ve never heard the muzzle blast even come out of the gun except when the moderator is off. It’s definitely the hammer and valve.

The stiffer spring in the valve.. Probably if I could increase it minorly it could be better, I am using the lightest valve spring from hill, I emailed him and he said it would be the quietest. He has a stiffer for the best ES, but only two options. What gets me is, I’m essentially adding a stronger spring when I increase the regulated pressure. So I expect the hammer strike to be louder.

What you said about the balanced valve actually makes me think I want it more.. if it requires less force to open than I can increase the pressure again for the same effect.. in volume with higher pressure pushing the valve closed.

I definitely think you hit hammer on the nail, pun intended, I need a lighter hammer but I don’t know of an option currently. Right now I think it’s the input force that’s too much, not output. I just got a shipping notification of 6springs I ordered to try from a spring vendor. This is my solution to lowering the inertial force of the hammer without reducing weight. I will look around for a lighter derlin hammer but I’ll probably end up trying the JSAR just to see if the material change is enough of a difference. Lol Hills website makes a dig at those hammers saying they expand in heat and humidity and could cause issue.

What does the bstaley oring mod do? It’s the second time I’ve seen the word bstaley today and I never have before today, weird coincidence. At this point I am trying to perfect anything I can so if it can help I’m interested.

Thanks for so much insight! Definitely got me thinking, really helps having someone who has tried this out!

 

[6gun]

I’m going to have to research this. But yeh it’s really not the air that I hear at this point. Just mechanical noise.

That's a hangup for me too but my buddy had to give me some perspective. He told me to listen to him shoot it.....its amazing how much isn't there when your skull isn't touching it.

Not the mrod at all and I often do this, but principles overlap. My impact hammer/valve was too noisey for me at higher power levels and eventually I stumbled on a theory that hammer weight might suit my situation. Stock spring with a heavy hammer and the experience has been much more pleasant.

As for my mrod, it's a dinosaur compared to you guys with new models. The valve event had always been loud but my air ping was worse. I'm not putting money into the old girl because of the tight gm choke, so how can we make the hammer quieter? I'm toying with ideas here on what could go where the travel adjust screw is that could handle quieting but not deform and cause problems down the line? As for now the minimum strike speed was essentially my answer. I figure it won't beat on the valve pin or hammer face as bad either.

 

[6gun]

I really like your drilling out the air holes idea to lighten the hammer. I suspected exactly what you’re saying about the derlin hammer, but if it really is an improvement than I can bump my reg pressure back up.

I will say, it’s always mechanical noise, I’ve never heard the muzzle blast even come out of the gun except when the moderator is off. It’s definitely the hammer and valve.

The stiffer spring in the valve.. Probably if I could increase it minorly it could be better, I am using the lightest valve spring from hill, I emailed him and he said it would be the quietest. He has a stiffer for the best ES, but only two options. What gets me is, I’m essentially adding a stronger spring when I increase the regulated pressure. So I expect the hammer strike to be louder.

What you said about the balanced valve actually makes me think I want it more.. if it requires less force to open than I can increase the pressure again for the same effect.. in volume with higher pressure pushing the valve closed.

I definitely think you hit hammer on the nail, pun intended, I need a lighter hammer but I don’t know of an option currently. Right now I think it’s the input force that’s too much, not output. I just got a shipping notification of 6springs I ordered to try from a spring vendor. This is my solution to lowering the inertial force of the hammer without reducing weight. I will look around for a lighter derlin hammer but I’ll probably end up trying the JSAR just to see if the material change is enough of a difference. Lol Hills website makes a dig at those hammers saying they expand in heat and humidity and could cause issue.

What does the bstaley oring mod do? It’s the second time I’ve seen the word bstaley today and I never have before today, weird coincidence. At this point I am trying to perfect anything I can so if it can help I’m interested.

Thanks for so much insight! Definitely got me thinking, really helps having someone who has tried this out!

You posted as I was writing and my theory is lower strike speed and spring tension with heavier hammer. It takes x amount of force for the valve event you want, and my thought was that velocity of hammer strike is a noise maker in carpentry too so what do we do? Buy a heavier hammer if that's your style.
A heavy hammer ist rebounded as fast by the air pressure on the valve pin either so I can get a little more dwell out of my opening and use my long barrel to take advantage.

Iirc b Staley is a stack of orings acting like a valve travel bump stop that strong arms the valves max travel on a given hammer strike.