Benjamin Huma regulator in Marauder 25 caliber

[Cbourbeau32]

Hello, my next investment for my Marauder is going to be a Huma regulator. I'm thinking of going with the one with the larger plenum. My questions are these :

Does anyone have a Marauder with either the standard plenum or larger plenum? If so, what psi/bar do you have it set at and what velocity are you getting with 25.39 and 33.95 jsb pellets? And also shot counts.

Would you also add an SSG along with the regulator?

Lastly, I think.....I read where someone was recommending a lighter hammer spring with the regulator. I would assume then that you would also want a lighter spring in the ssg also then, correct?

I'm hoping to hear from those who have added one or both of these components.

Thank you!

 

[3Crows]

I am running the XXL plenum on both of my Huma regulated .25s. One has a "Cobra" valve and the other has the JSAR balanced valve. Both use FFH/SSG lightweight hammers. I can push velocities well beyond practical for pellets, even with the JSB 34s. But shot count is compromoised due to the small reservoir capacity. The JSAR rifle is currently set for around 860 fps with the 34s for 16+ shots on the reg plus four more before velocity declines. The Cobra rifle will do 24 shots on the reg with JSB Hades at 860 fps. Both are supremely accurate. As well, both have JSAR aluminum tubes. I did take porting to .19 for both rifles. Reg is set to about 1,900 psi on both. I use a 3,000 psi fill.

The Cobra rifle with remains of the day:



The JSAR rifle with little buddy:

 

[Cbourbeau32]

I am running the XXL plenum on both of my Huma regulated .25s. One has a "Cobra" valve and the other has the JSAR balanced valve. Both use FFH/SSG lightweight hammers. I can push velocities well beyond practical for pellets, even with the JSB 34s. But shot count is compromoised due to the small reservoir capacity. The JSAR rifle is currently set for around 860 fps with the 34s for 16+ shots on the reg plus four more before velocity declines. The Cobra rifle will do 24 shots on the reg with JSB Hades at 860 fps. Both are supremely accurate. As well, both have JSAR aluminum tubes. I did take porting to .19 for both rifles. Reg is set to about 1,900 psi on both. I use a 3,000 psi fill.

Thank you! Do you think I would get decent results with the standard valve and the Airgun Revisions ssg (he might be able to put a lighter spring in it for me.... I'd ask him) I do have a slightly larger transfer port.

Also, do you have your velocity adjustment screw open all the way?

 

[3Crows]

Thank you! Do you think I would get decent results with the standard valve and the Airgun Revisions ssg (he might be able to put a lighter spring in it for me.... I'd ask him) I do have a slightly larger transfer port.

Rich does make a nylon hammer SSG, I have one, though it does not show in his current catalog. Ask him about it. You will need to port the rifle barrel to at least .161 and go to a larger TP of .161, either from Tim Hill or make one. You have to improve the breathing by the larger porting because you will be operating the regulator at pressure at or just below what was probably your former bottom of the Bell pressure.

What does your rifle currently shoot at with the pressure at 2000 psi? If you increase the regulator pressure above 2000 psi your shot count will be awful. You only have about 190cc HP reservoir once the XXL plenum and regulator are installed, down from 210cc.

Not meaning to speak for Mr. Rich but in conversations with him he prefers non regulated M-Rods. Here is one of my regulated rifles, velocity turned down a little to get a good shot count:

 

[3Crows]

Here are my four .25 M-Rods:



The two upper rifles are not regulated and use AGR hammers and AGR hybrid reservoir tubes. The Gen 1 shoots JSB 25.4 pellets for 32 shots at 860 fps (modded Crosman valve) and the Gen 2 below will shoot JSB 34s also at 860 fps (Tim Hill valve) for 27 shots. I have found that JSB pellets and M-Rods seem to produce best accuracy and plenty of energy at 860 fps unregulated or regulated. The two lower rifles are very lightweight and use all aluminum reservoir, Huma regs and are very nice shooters, easy to cock, very accurate.

 

[$p00kygH0ST]

Here are my four .25 M-Rods:



The two upper rifles are not regulated and use AGR hammers and AGR hybrid reservoir tubes. The Gen 1 shoots JSB 24 pellets for 32 shots at 860 fps (modded Crosman valve) and the Gen 2 below will shoot JSB 34s also at 860 fps (Tim Hill valve) for 27 shots. I have found that JSB pellets and M-Rods seem to produce best accuracy and plenty of energy at 860 fps unregulated or regulated. The two lower rifles are very lightweight and use all aluminum reservoir, Huma regs and are very nice shooters, easy to cock, very accurate.

I'm sorta kinda getting this sinking suspicion you like Benji Marauders.

 

[3Crows]

I'm sorta kinda getting this sinking suspicion you like Benji Marauders.

Sinking? Okay, I guess. Do not sink too far please. I guess after I bought the first one and modded it I had nearly enough parts to build another left over. So after I built another I had even more nice parts left over so built yet another and so on. So the first rifle infused it's DNA into the following three and I just happen to have enough parts that if I just buy a few more parts, well, so it goes.

Oh, and thanks to several members here and on GTA who gifted me a barrel, a valve, a plenum, a trigger group and so on. Very much appreciated sincerely .

 

[scottc]

Thank you for sharing Huma results, will pass info on to new m-rod owner friend.

 

[3Crows]

Also, do you have your velocity adjustment screw open all the way?

The regulated rifles with the JSAR valve and the Cobra valve do not have a velocity adjustment (port blocking) screw. If you install a regulator that screw will need to be fully out of the flow path and the barrel port to at least .161. The transfer port likewise.

A regulator with the stock valve, I do not really know. I suspect that with the "velocity" screw fully retracted and .161 TP and barrel port the rifle will do okay but do not expect big power. Should be able to get a good shot count but pushing the JSB 34s might be too much beyond high 700s or low 800s. Might need to install a lighter poppet return spring.

My unregulated Gen 1 with a modded Crosman valve (larger port), .161 TP and barrel port shoots the JSB 25.4 pellets for up to 32 shots at an average of 860 fps, Bell curve. Yes, the restrictor screw is fully out of the path.

 

[Cbourbeau32]

What does your rifle currently shoot at with the pressure at 2000 psi?


Good morning, I don't currently have a regulator in my Marauder.

 

[3Crows]

@Cbourbeau32, I understand you do not have a regulator installed. That is why I asked what does your rifle currently shoot for velocity and pellet when the reservoir is depleted to 2000 psi, 1900 psi, 1800 psi? Because that is what it will do with a regulator installed in an otherwise stock form minus a little bit less for the plenum reduction (entire reservoir unregulated vs just the space behind the Huma reg, standard or XL, regulated).

As I said earlier, the regulator pressure will be set somewhere at or below 2000 psi. I set mine currently at 1900 psi. That gives me 1100 psi headroom in the reservoir. Each shot will drop the reservoir pressure but the plenum pressure will remain at your set point (for me again at 1900 psi) and velocity will be constant until the reservoir pressure falls below the set point pressure. Then your velocity will drop with each shot, quite steeply possibly.

That is right, drop your fill pressure to whatever your desired future regulator set pressure would be. Then load your pellet of choice and shoot the rifle over a chronograph and that is the velocity you will see roughly with the Huma installed and set to that pressure with an otherwise stock rifle. You can answer your initial question that simply. But, of course, once the reg is installed, you will want to mod the valve port, the TP ID and the barrel port to regain some velocity lost due to the now lower plenum working pressure and reduced plenum volume with the reg installed.

My porting, valve, TP, barrel, on my unregulated rifles is .161 and on my regulated rifles .190. I can go slightly larger still. I suggested the .16 diameter as an initial starting point above stock because it is easy to remove metal but not so easy to put it back. Once regulated and the barrel and valve are ported, if you then choose to go back to unregulated your only means of restricting the flow path would be to install TPs of smaller or different ID. My experience tells me that .16 is a good compromise.

The rifle in that shot graph I gave is not stock. It has .191 barrel porting, Cobra valve with largest possible internal path, a custom made TP of large ID, JSAR aluminum reservoir and the AGR lightweight SSG. It has the reg set at 1900 psi. It can be pushed up past 60 fpe but it is set for 52 fpe to preserve a good shot count.

 

[Cbourbeau32]

That is right, drop your fill pressure to whatever your desired future regulator set pressure would be. Then load your pellet of choice and shoot the rifle over a chronograph and that is the velocity you will see roughly with the Huma installed and set to that pressure with an otherwise stock rifle.

I get it now, thank you! Maybe I should order the ssg first and play with it first to see how high velocity I can get around the 1900 psi range while I'm saving for the huma.

 

[3Crows]

I get it now, thank you! Maybe I should order the ssg first and play with it first to see how high velocity I can get around the 1900 psi range while I'm saving for the huma.

Yes, I agree you should do that.

Once a regulator is installed you will be shooting at the reg set pressure. With the unregulated (.25) M-Rod you are shooting, or at least I am, starting with a fill pressure of 3000 and usually down to about 1800 psi before the Bell curve drops off into the Grand Canyon. With the reg installed you are working at that bottom pressure you would normally have topped the rifle back off at. The only way to get your velocity back up once the regulator is installed is to port the rifle (including the valve or switch to a different valve). If I recall the standard porting for the M-Rod as it comes is around .14. That will be very restrictive to a regulated rifle working at 1800 to 2000 psi plenum pressure.