Tuning Marauder tuning

[HW95Guy]

I bought a .25 cal marauder about 2 months ago, I get about 32 solid shots from 2600psi to 1500 psi. Not too sure on FPS as I don't have a chronograph but I would like to try to achieve 40 shots at 40FPE. I was looking at a huma regulator and the Hill Airgun .25 cal regulator kit. I wouldn't mind buying a chronograph aswell for tuning purposes. Any input on requirements to achieve this goal would be appreciated!

 

[Saltlake58]

I have a .22. Several years ago, Tom Holland and the folks at Hill Airguns talked me through installing a regulator and upping my shot count from 30 to abut 55 per fill. I did reduce the power to achieve that. Right now, it fires an 18.3 grain JSB at about 830fps. That gives me roughly 28 fpe at the muzzle.

I ended up installing a lighter Hill Hammer, trying several hammer springs, installing the Hill transfer port and a couple other things along the way. Biggest issue was air. To install or adjust the regulator, you must degass the gun, remove the regulator, set the regulator, and reassemble and refill the gun. Hand Pumping really isn't an option for this kind of tuning. Also, the air tube has holes punched for the trigger group and to attach to the rest of the gun. It's punched, so very sharp edges. I ended up polishing the insides so I could install the O-Rings without ripping them to bits.

What I just said above might sound terrible, but it was well worth it. I think I spent about $150 including the regulator, and now it shoots extremely consistently for over 50 shots. I just bought 5 magazines and when they are empty, I refill the gun.

As for a chronograph, I have a Caldwell and the FX chronographs. Much prefer the FX. simple to setup, if you go to the range, no funky activities in front of the bench (makes the range masters much happier), and keeping shot strings is simply an email away. It is pricey, but works well. Hint, move it back on the gun. Mine doesn't like being right at them muzzle, it likes being back 6 or 8 inches.

good luck, it's an excellent platform!

 

[HW95Guy]

So did you end up keeping the regulator in the gun or did you end up removing it? I figure even if I get 30 FPE and get 45-60 shots I would be very happy. The less filling and more shooting the better.

I shoot 25 grain Air Arms pellets and with the set up now its for backyard shooting and pesting... its extremely accurate at 50 yards and very quiet, I would really just like more accuracy and shots. 40FPE would really be just to try out not a forever thing, as the way it sits I can pick off squirrels at 50 and they drop right away.

 

[dizzums]

i generally am not looking for alot of shots from mine .. with the stock tune its doing 870ish probably with jsb 25's and i figure 2 clips from 2800 or so and that keeps me dialed ... personally i want more power but from everything ive looked into theres really no cheap way to do it .. at the same time if its got the right equipment in it like a lighter hammer and a different spring etc it can be tuned to a regulator alot better from what i understand ... anyway ... the route i went is with 'Hill' stuff .. the guy is knowledgeable, has compatible stuff, and although i havent, i understand he's readily available to give advice on the stuff he sells ... so im getting ready to move up to 33's for more punch and upgrading my old mrod .. heres where im at -

 

[av8r]

I have a 22 that went through pretty much the same as Saltlake58. I installed a Huma regulator, then a Hill lightweight hammer, spring, and transfer port. I have a Caldwell chronograph to help in the tuning and followed Tim Hill’s suggestions on hammer spring settings for various power ranges. The regulator is set at approx 115 bar, the transfer port screw is fully open, and 3 turns on the hammer spring gives me 840 fps with Air Arms 16g pellets, over 50 shots.

 

[MileHighAirGunner]

I modified the air stripper on my .25 cal Marauder this weekend. Drilled out the ports to 3/16” and angled them rearward. There might be a slight difference in the report now. Don’t have anything to measure it but it seemed slightly quieter to my ears. More importantly, I did gain about 10 fps average. Was shooting around 840’s with the JSB 25.39 Kings now I’m around 850’s. Which is nice. I’m going to attempt to make a brass insert next to make it more of a true air stripper. I’ll spend more time cleaning up the air stripper a bit more once I get the insert made. 
I’ve bought numerous things from Tim Hill. Great guy and he will answer any questions you got. I used the HUMA regulator in all three of my Marauders. just don’t get the one with the gauge port if your trying to get 40 fpe with 1600 psi reg pressure on the .25. Too small of a plenum. Tim told me he he used this one https://www.ebay.com/itm/162104913497 and said to ask for the 55 mm spacer but I used the xxl HUMA plenum.

 

[av8r]

MileHighAirgunner’s pic reminds me that Talon Tunes does sell an air tube extension which would increase your shot count.

 

[Xbowsniper]

HW95Guy,

Tim Hill is the authority on higher power Marauder tunes, particularly with the larger calibers. I don't have a lot of experience with the larger calibers, my thing is .177 lower power (12ftlb). The most important part of the equation, is to get a chronograph. Without one, you might as well not modify anything until you do. I have an Air Chrony made in the Czech Republic, and it's the best chronograph I have used to date, and, unlike others, it's not light sensitive. Bright sun, shade, indoors, and even a dark room, works flawlessly. It's a few more dollars than the rest, but worth it. And it's compact.

Also, the Archer Airguns tool that they sell to plug up that gauge hole in the tube, is a priceless item for rebuilding and tuning a Marauder. Prevents the o rings from being damaged on the valve, and gauge block during installation. 

Sorry I can't be of more help, but higher calibers and powers are Tim Hills Specialty, not mine. If you have any questions about rebuilding the Marauder, don't hesitate to ask, they are all basically the same. There are some things that you can do to it, that will enhance the consistency and smoothness of the shot cycle.

Tom Holland 

Field Target Tech 

Fieldtargettech.com 

 

[huntr]

I bought a .25 cal marauder about 2 months ago, I get about 32 solid shots from 2600psi to 1500 psi. Not too sure on FPS as I don't have a chronograph but I would like to try to achieve 40 shots at 40FPE. I was looking at a huma regulator and the Hill Airgun .25 cal regulator kit. I wouldn't mind buying a chronograph aswell for tuning purposes. Any input on requirements to achieve this goal would be appreciated!

You have no idea if you're getting 32 SOLID shots, velocity or power-wise, without a chronograph. Just that you are getting 32 shots. Especially from 2600 to 1500. Experience with my gun says when you start dropping much below 2000, you're velocity is starting to drop pretty steadily, in the stock gun.

Email Tim Hill and see if 40 shots @ 40 fpe is possible with his valve kit and Huma regulator. I'm not sure it is. Tim responds very quickly and is a big help.

I recently installed the Hill High Performance Matched Parts Kits with the added PEEK strikers, in my .22 and .25 Marauders. I'm very satisfied with the results, but I was going for more power. I didn't have the desire or nerve to drill my barrel for the Max Power.. I would recommend you order his stop pin for $1.98 at the same time. My hammer spring kept self adjusting and steadily loosing velocity. Installing the pin ensures your hammer spring tension stays where you adjust it.

The Hill kits eliminate the ability to degas your gun in the manner you can do with the factory valve, because the adjustable port is eliminated. He recommends shooting the gun down to about 200 psi then loosening the manometer. Just food for thought. It's not a big deal to me, but I didn't install a regulator that you might want to access to adjust.

Again, Tim is very prompt and accommodating via email. 

 

[adeline112]

I modified the air stripper on my .25 cal Marauder this weekend. Drilled out the ports to 3/16” and angled them rearward. There might be a slight difference in the report now. Don’t have anything to measure it but it seemed slightly quieter to my ears. More importantly, I did gain about 10 fps average. Was shooting around 840’s with the JSB 25.39 Kings now I’m around 850’s. Which is nice. I’m going to attempt to make a brass insert next to make it more of a true air stripper. I’ll spend more time cleaning up the air stripper a bit more once I get the insert made. 
I’ve bought numerous things from Tim Hill. Great guy and he will answer any questions you got. I used the HUMA regulator in all three of my Marauders. just don’t get the one with the gauge port if your trying to get 40 fpe with 1600 psi reg pressure on the .25. Too small of a plenum. Tim told me he he used this one https://www.ebay.com/itm/162104913497world of solitaire and said to ask for the 55 mm spacer but I used the xxl HUMA plenum.

• 
  I need help tuning FX Impact M3 .22 cal . I had 250 bar on regulator and shot 25-30 H&N 18 and used down to 210 bar off the 250 charge. I would like to get a more efficient use from my 300 cc compact 500mm, I'm shooting 851 fps +- with H&N 18(18.13) Reg #1 150 bar,Reg #2 pressure gauge 75.The micro set @2,Macro 16 fronyt valve looks like 5.5-6 turns. This was set at factory with no adjustments. Any tuning help would be greatly appreciated .
  

 

[Saltlake58]

I kept the regulator. Much prefer 50 consistent but slightly lower powered shots. gun is extremely accurate out to 50, so excellent platform for pesting. Also sets the standard for quiet. That's a huge area for baffles and air to move through when shooting.

The key is only one modification at a time. By that, I mean, install the parts you want, then adjust one thing at a time, test, see where you are, do it all over again. In my case, I found a regulator setting at about 1800 PSI then adjusted the springs and hammer tension around that, one adjustment at a time. It's time consuming, but at least you only have to undo one thing if you push it a little too far.

A lighter spring and hammer turned out to be key to getting the performance I wanted. The stock spring and hammer just couldn't be tuned low enough for me. In your case with a .25, they might be fine, you just have to test to find out.

 

[MileHighAirGunner]

MileHighAirgunner’s pic reminds me that Talon Tunes does sell an air tube extension which would increase your shot count.

Yes that is we’re I ordered mine from. They are 6” long and add approximately 70 cc of air. My Marauders are bullpups so even with the extension and longer shroud my Marauders are 36-1/2” long which is still shorter than the stock Marauder in their OEM stocks. I didn’t like the weight of the Marauder as a rifle and much prefer them in the bullpup configuration. 

 

[MileHighAirGunner]

I modified the air stripper on my .25 cal Marauder this weekend. Drilled out the ports to 3/16” and angled them rearward. There might be a slight difference in the report now. Don’t have anything to measure it but it seemed slightly quieter to my ears. More importantly, I did gain about 10 fps average. Was shooting around 840’s with the JSB 25.39 Kings now I’m around 850’s. Which is nice. I’m going to attempt to make a brass insert next to make it more of a true air stripper. I’ll spend more time cleaning up the air stripper a bit more once I get the insert made. 
I’ve bought numerous things from Tim Hill. Great guy and he will answer any questions you got. I used the HUMA regulator in all three of my Marauders. just don’t get the one with the gauge port if your trying to get 40 fpe with 1600 psi reg pressure on the .25. Too small of a plenum. Tim told me he he used this one https://www.ebay.com/itm/162104913497world of solitaire and said to ask for the 55 mm spacer but I used the xxl HUMA plenum.

• 
  I need help tuning FX Impact M3 .22 cal . I had 250 bar on regulator and shot 25-30 H&N 18 and used down to 210 bar off the 250 charge. I would like to get a more efficient use from my 300 cc compact 500mm, I'm shooting 851 fps +- with H&N 18(18.13) Reg #1 150 bar,Reg #2 pressure gauge 75.The micro set @2,Macro 16 fronyt valve looks like 5.5-6 turns. This was set at factory with no adjustments. Any tuning help would be greatly appreciated .
  

sorry, I don't own an Impact. Not sure I'd be much help to you.

 

[Bigragu]

I was able to achieve the 40/40 tune with Hill parts. Regulator was set at around 1800 or 1900(going from memory) and shooting the 25 cal 28.40 barracuda hunter extremes at around 838 FPS. The final mod that got me there was a guy from the GTA modded my bolt to a smaller diameter to assist in the air flow. 


that’s been a long time ago. When I invested in a compressor I pulled away from the air saving 40/40 tune and ramped up my marauder to shoot the same pellets at around 880 for around 19 shots

 

[huntr]

I didn't go regulated because I didn't like the idea of not knowing the tank pressure when filling from an external tank/bottle, and I didn't know how to get around that without somehow making another mod to add a second manometer. Plus, I do have a compressor capable of filling my own external tank/bottle. Which means conserving air and sacrificing power, when I'm away from home, was not important to me.

 

[HW95Guy]

Thanks everyone for the plethora of info, I will look into getting a chronograph to start and go from there! The guy before me said it was clocked at roughly 840 with 25 grain pellets so that would already be at 40FPE wether that is still the case is to be determined!