Author Topic: Mrod reg (Read 3795 times))

dpittman · « **on:** February 24, 2018, 09:52:53 PM »

I have a stock .25 mrod and have a question about the Huma regs. With or without the gauge block hole. With the built in gauge hole does it have enuff plenum for decent power. What kind of power and shot count can be had with the proper valves and hammer springs and hammers. How do some get high power with a very low cocking force.

KnifeMaker · « **Reply #1 on:** February 25, 2018, 01:55:20 AM »

Remember, if you go with the guage block system, you are not going to be venting the reg to the atmosphere. So drilling the tube is needed.

I went with no gauge, and the gauge hole is used for the vent.

Besides, I only trust the gauge on the fill bottle. AG guages are notorious for being off by several hundred pounds.

Knife

KnifeMaker · « **Reply #2 on:** February 25, 2018, 01:56:09 AM »

Quote from: KnifeMaker on February 25, 2018, 01:55:20 AM

Remember, if you go with the gauge block system, you are not going to be venting the reg to the atmosphere. So drilling the tube is needed.

I went with no gauge, and the gauge hole is sued for the vent.
Besides, I only trust the gauge on the fill bottle. AG gauges are notorious for being off by several hundred pounds.

Knife

Mikeyblue · « **Reply #3 on:** February 25, 2018, 09:55:43 AM »

I was think g of the huma because I thought it was no drill? I tried looking at the installation instructions but don’t see anything? I’m a newbie so may have missed?

Dairyboy · « **Reply #4 on:** February 25, 2018, 10:08:37 AM »

The one with the gauge port is actually vented to the atmosphere. You can still get plenty of power out of one as well. I prefer the ones with the gauge port built in. Much easier to work with and don't hafta worry about the other one sealing well.

Rat Sniper (AKA: PaulT58) · « **Reply #5 on:** February 25, 2018, 10:50:58 AM »

I'm a newbie also, and just installed a Huma regulator with the gauge port in my .25 Marauder. I did not have to drill a vent hole. Since I really don't know what I'm doing, I'm at a point where I'm not sure what to do next. The gauge is showing a regulated pressure of 2300 psi. I have the MDS hammer and TSS installed, but I can only get and average of 727 fps for an average of 29.78 fpe using JSB 25.39 gr pellets. This is over a 40 shot string, but only 28 of those are above regulated pressure.

My .22 Marauder has the Audrius regulator, the regulated pressure is 2000 psi and I get an average of 862 fps for an average of 26.23 fpe using JSB 15.89 gr pellets. Again, this is over a 40 shot string with 33 shots at the regulated pressure. This rifle has the stock hammer and hammer spring.

I guess what is so confusing to me is my Gauntlet has a regulated output of only 1300 psi, yet I'm averaging 896 fps for an average of 25.42 fpe using CPHP 14.3 gr pellets. Over the 40 shot string all 40 shots are at the regulated pressure.

I understand the Gauntlet has a lot more air volume, but why can I get higher fps/fpe with less regulated pressure than I am with the Marauder?

I would love to know if it's even possible to get 850 psi out of the .25 Marauder at a regulated pressure of 2000 psi or under with the set up I currently have?

Likewise, I'd love to know if I could get 900 fps out of the .22 Marauder at a regulated output of around 1500 psi using the setup I currently have?

I'll admit, I don't really understand the inner workings of these rifles, but I am trying to learn. Now that YouTube is pulling all the air gun videos, it's getting tough to find clear, concise explanations and instructions that someone who is just starting out can understand and follow...

Dairyboy · « **Reply #6 on:** February 25, 2018, 11:12:55 AM »

Paul does the .25 Mrod have stock valve and ports?

Rat Sniper (AKA: PaulT58) · « **Reply #7 on:** February 25, 2018, 11:21:37 AM »

Quote from: Dairyboy on February 25, 2018, 11:12:55 AM

Paul does the .25 Mrod have stock valve and ports?

Yes, it's all stock with the exception to the regulator, hammer and hammer spring. I'm trying to do the best I can and stay within a budget, that I've already exceeded! LOL!

FuzzyGrub · « **Reply #8 on:** February 25, 2018, 12:25:08 PM »

Mrod Huma reg w/gauge port: vents out gauge hole, fixed sized plenum
Mrod Huma reg wo/gauge port: vents out gauge hole, can be used with or without gauge block, so two plenum sizes to choose from. Same as audrius reg

FuzzyGrub · « **Reply #9 on:** February 25, 2018, 12:37:54 PM »

Quote from: PaulT58 on February 25, 2018, 11:21:37 AM

Yes, it's all stock with the exception to the regulator, hammer and hammer spring. I'm trying to do the best I can and stay within a budget, that I've already exceeded! LOL!

If you just install a reg but keep same ports, it will be lower power at a given reg pressure. Think of it this way, you kept everything else the same but gave it just a tiny air tube (plenum) at a lower pressure than probably what you used for conventional tune. You open the ports to get more power at that smaller plenum and lower pressure.

Rat Sniper (AKA: PaulT58) · « **Reply #10 on:** February 25, 2018, 01:25:06 PM »

Quote from: FuzzyGrub on February 25, 2018, 12:37:54 PM

Quote from: PaulT58 on February 25, 2018, 11:21:37 AM
Yes, it's all stock with the exception to the regulator, hammer and hammer spring. I'm trying to do the best I can and stay within a budget, that I've already exceeded! LOL!

If you just install a reg but keep same ports, it will be lower power at a given reg pressure. Think of it this way, you kept everything else the same but gave it just a tiny air tube (plenum) at a lower pressure than probably what you used for conventional tune. You open the ports to get more power at that smaller plenum and lower pressure.

When you refer to opening the port are you referring to the adjustment that can be made by removing the grub screw your n the side of the rifle? Or does it mean replacing more parts?

FuzzyGrub · « **Reply #11 on:** February 25, 2018, 01:36:53 PM »

Quote from: PaulT58 on February 25, 2018, 01:25:06 PM

When you refer to opening the port are you referring to the adjustment that can be made by removing the grub screw your n the side of the rifle? Or does it mean replacing more parts?

At a minimum, modifying existing parts. For "typical" Mrod regulation, the following TP, valve exhaust and barrel port should be around:

177: 0.140"
22: 0.160"
25: 0.180"

The valve velocity setting on all, should be "wide open".

I think the oem standard TP is 0.110-0.120 for both 177 and 22, and 0.140" for 25 cal.

Rat Sniper (AKA: PaulT58) · « **Reply #12 on:** February 25, 2018, 02:24:57 PM »

Quote from: FuzzyGrub on February 25, 2018, 01:36:53 PM

Quote from: PaulT58 on February 25, 2018, 01:25:06 PM
When you refer to opening the port are you referring to the adjustment that can be made by removing the grub screw your n the side of the rifle? Or does it mean replacing more parts?

At a minimum, modifying existing parts. For "typical" Mrod regulation, the following TP, valve exhaust and barrel port should be around:

177: 0.140"
22: 0.160"
25: 0.180"

The valve velocity setting on all, should be "wide open".

I think the oem standard TP is 0.110-0.120 for both 177 and 22, and 0.140" for 25 cal.

Okay, thank you! I'm assuming the cost of a TP should be minimal compared to the regulator and other parts. Is this a part that can be purchased at those sizes, or do I need to just purchase a stock TP and modify it myself? Sounds like this may be the key piece I'm missing! Thanks...

FuzzyGrub · « **Reply #13 on:** February 25, 2018, 02:49:48 PM »

Quote from: PaulT58 on February 25, 2018, 02:24:57 PM

Okay, thank you! I'm assuming the cost of a TP should be minimal compared to the regulator and other parts. Is this a part that can be purchased at those sizes, or do I need to just purchase a stock TP and modify it myself? Sounds like this may be the key piece I'm missing! Thanks...

To modify a stock TP to 0.180" makes it too thin and crushes very easily. I use poly tubing. The exhaust port on the valve will needs to be drilled out along with the barrel port to match. If you mess up a valve, it is only around $25. or you can buy a drop-in from Hill and others.

You mentioned going to a LW hammer. How light did you go? If still using the oem valve spring, that can be part of the issue, as well.

Rat Sniper (AKA: PaulT58) · « **Reply #14 on:** February 25, 2018, 06:22:45 PM »

I'm not comfortable enough, nor do I have the self confidence to start modifying the stock parts! I have no idea the weight of the Hammer. I got it from Rocker1 right after I bought the rifle because I was told it was a must have! LOL! The more I read different posts about tuning, the more confused I become. I want to learn, but it sure would be nice if there was an instruction manual that gave some common settings to try first and then adjust from there...

This is where I'm at now... I closed the Velocity Port on both rifles and then opened them a full 5 turns. On the .22 I brought the striker all the way back next to the body of the hammer and backed the hammer spring all the way out and then went to shooting and adjusting over the chrony. I have that one sitting right at 900 fps using JSB 15.98 gr pellets, so I'm happy with it. I't bone stock except for the regulator that is set at 2000 psi.

The .25 is another story. Did the same thing but the best I can get is 725 fps with JSB 25.39 gr pellets. I'm kind of disappointed in the results and am thinking of removing the MDS Hammer and the TSS and going back to stock and see what happens.

I don't know if I fully understand the function of the TSS, but it's almost as if the adjusting screw should be twice as long as it is. Twice I adjusted it to the point it went right through and then I had to disassemble the rifle to get it threaded back into the back piece. I thought the idea was having two springs that could be adjusted independent of one another, but it appears the adjuster pushes both springs equally. Or at least they do when I'm at a point where the rifle is making more than 500 fps! If the adjuster is just moving the inner spring, the rifle is producing less than 500 fps... I'm not sure if it will work, but maybe I'll try replacing the outer spring with the stock spring and see what happens...

My goal was to get between 800-850 fps, but as it sits it doesn't appear to be capable of producing that output...

UPDATE: I swapped hammer springs and put the stock hammer spring in the TSS and have been able to get a pretty consistent 800 fps from my .25 Mrod. Still thinking I need to do something different, but for now, it is workable...

dpittman · « **Reply #15 on:** February 25, 2018, 09:49:25 PM »

With the reg with gauge hole how much power should I expect. My gun likes the 34 gr jsb better than the 25.39 pellets. It is shooting them around 725 fps and the kings around 830. But I only get about 16-20 shots. Is it possible to get the 34 gr up to 800 fps and have 25-30 shots with a regged gun. I am liking all the Jefferson State toys that can be put in one of these mrods.

FuzzyGrub · « **Reply #16 on:** February 26, 2018, 07:56:59 AM »

Quote from: dpittman on February 25, 2018, 09:49:25 PM

With the reg with gauge hole how much power should I expect. My gun likes the 34 gr jsb better than the 25.39 pellets. It is shooting them around 725 fps and the kings around 830. But I only get about 16-20 shots. Is it possible to get the 34 gr up to 800 fps and have 25-30 shots with a regged gun. I am liking all the Jefferson State toys that can be put in one of these mrods.

Keith (TriggerTreat) and Dillon (Dairyboy), I believe did some tuning with a reg for the heavier JSB. They might have used a larger plenum Huma, designed for 30 cal, vs 25. They would also have porting info or what aftermarket valve they used.

FuzzyGrub · « **Reply #17 on:** February 26, 2018, 08:21:47 AM »

Quote from: PaulT58 on February 25, 2018, 06:22:45 PM

I'm not comfortable enough, nor do I have the self confidence to start modifying the stock parts!

Paul,

If you mess up the stock parts, they are available from crosman at reasonable prices. Getting the ports to even 0.160" will help you.

A number of people have documented Mrod 25 cal regulation projects on the GTA. They either modify the existing valve and ports or use an aftermarket valve.

If you are unable to do the porting, bump up the reg psi another 100-200. That will get you some more power, but reduce the number of shots on regulation.

Rat Sniper (AKA: PaulT58) · « **Reply #18 on:** February 26, 2018, 09:26:19 AM »

Quote from: FuzzyGrub on February 26, 2018, 08:21:47 AM

Quote from: PaulT58 on February 25, 2018, 06:22:45 PM
I'm not comfortable enough, nor do I have the self confidence to start modifying the stock parts!

Paul,

If you mess up the stock parts, they are available from crosman at reasonable prices. Getting the ports to even 0.160" will help you.

A number of people have documented Mrod 25 cal regulation projects on the GTA. They either modify the existing valve and ports or use an aftermarket valve.

If you are unable to do the porting, bump up the reg psi another 100-200. That will get you some more power, but reduce the number of shots on regulation.

John,

Thank you for all your help. I replaced the outer TSS spring with the stock spring yesterday evening and was able to get it at 800 psi using 25.39 gr pellets. Daylight was fading so the chrony was starting tor port errors and I had to quit. Later I replaced the TP with a piece of refrigerator tube. I have no idea if this will work in the Marauder or not, but it did fit in the port opening and I cut it the same size as the stock port with the two bushings attached. If I get a break in the weather today, I'll give it another go and see what happens. I really appreciate you patience and suggestions!

dpittman, what set up/aftermarket parts do you have installed in your Marauder? I don't seem to be able to get past 800 psi using the 25.39 pellets with my current configuration. Thanks...

deepbass9 · « **Reply #19 on:** February 26, 2018, 12:21:02 PM »

This is a great thread...I've been reading along and have read a ton in the past 6 months, but like Paul and some of the other guys...sometimes a lot of what gets written here does so with a bit of assumed knowledge on the part of the readers or, rather, the writer is just speaking from their head. I think after 6 months I finally know what a poppet valve is...

I just purchased a modded .22 and .25 to replace my stock .25. Since I didn't do the work myself, unless I plan on sending them out, I'm going to have to start twiddling. My .22 is reg'ed @ 140 bar and ported to .140 valve, TP, and barrel. I just got it so I haven't chronied it yet, but the seller sent it with specs that show 50 reg'ed shots at about 900 average. The .25 is not regulated, but ported to .170 and averages 892 over 20 shots, according to the sheets that came with it. This is with a TSS and MDS hammer.....22 has SSG installed.

So, close to 900 with an unregulated using 25.49 gr. with just porting, lighter hammer, and spring system as others have done is achievable with trial and error. I watched Haji's video, which with the Youtube thing, was a great tear down resource.

If I can interject a question...when you take down that way, and take the breech off and the hammer and springs off, I'm assuming since you/Haji didn't mess with the spring system adjustment via the screw/hole that's at the rear cap there's really nothing to set back up when you reassemble, correct? I mean, the spring settings for the hammer should all be the same, right...you just put the springs in and the cap back on behind where the bolt goes and whatever your original settings were should still be there, correct?

I only ask because the seller said the TSS for the .25 was a bit of a bear to set up, and right now there is a slight leak in the air tube. I want to know in case I have to disassemble to replace o-rings, etc. Thanks!

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Mrod reg

Author Topic: Mrod reg (Read 3795 times))