Maximus Prime

[FuzzyGrub]

OK, after doing some checking over the weekend, I think I have come up with my next project.   It is going to be a meld of a Maximus and Prod/Mrod parts.   The key first step will be fitting a Prod valve to the maximus air tube.   It looks like the valve will fit, but only have two of the three valve retainer screws.  So with Magnum Airgun upgraded screws, it will only be a 2400psi max fill, unless I find a way to secure a 3rd screw.  Note: there is a hole in the maximus air tube too close to drill for the standard spot on the prod valve. 

WARNING!  This thread shows modifications done to the air tube.   These modifications may have extreme safety consequences.   No analysis or testing has been done to verify any safety margins.  Any modifications done are at the risk of those performing them.   

One question I have is about the maximus gauge block.  While pictures I’ve seen it looks like a disco gauge block, but from the maximus schematic it has a different part number.  That leads me to something has changed in it, and my suspicion is the length is slightly different.   I suspect that change might have been necessary to go with new valve but keep gauge port hole the same for stock compatibility.    I am planning on using the Prod gauge block, but if it is too long, would have to mod a maximus one.  Anyone know what the change was?

Other Parts:
- Mrod Gen 1 trigger
- Prod Breech & Bolt (need to drill air tube)
- Prod End cap/adj & Hammer
- Mrod barrel
- Custom length shroud

Initial parts were ordered this AM.  Ordered the syn stock for now, was only $18 and change.  A boyd's will probably replace it, once the project gets near completion. 

[Evo Shift]

Seems like a lot of work.

How much total money and time will you have invested in this project?
What will make the end result better than something you could have bought off the shelf for around the same money?
I'm sincerely asking. 

[K.O.]

 hey Fuzzy love the hybrid builds as you know, will be watching and learning...

[FuzzyGrub]

hey Fuzzy love the hybrid builds as you know, will be watching and learning...

Kirby, we'll see how these crosman lego's go together.     This shouldn't be a busy time for crosman, and might have the parts by the end of the week.   I have a prod air tube, so making the drill template should go well. 

[2K1TJ]

Interesting project!

Curious what your goals are. And why the Prod valve instead of the Disco or.Maximus? Higher shot count maybe?

[FuzzyGrub]

Interesting project!

Curious what your goals are. And why the Prod valve instead of the Disco or.Maximus? Higher shot count maybe?

Two of the Prod breech screws thread into the valve.   I don't believe the maximus or disco valve have enough material in that area.  Even if they did, getting it right with DIY caveman tools would be a challenge. 

It will be the mate to this rifle:



It will start off life as a 22 cal, because that is what barrel and bolt I have.  Plan would be to go to 177 cal (waiting for F&T barrel) and would probably get a regulator at that time.  Mrods are about as heavy a gun as I'd like to carry, but prefer something lighter. 

[39M]

I like this idea of a lighter weight repeater with the shrouded barrel.

Of course I don't know much about pressure tolerances of the mixing and matching parts from different guns with different fill pressure.

But the valve and retainer screws are the weak link and not the tube itself?
The Disco and Maximus tubes are  equal in strength?

[Rob M]

I like this idea of a lighter weight repeater with the shrouded barrel.

Of course I don't know much about pressure tolerances of the mixing and matching parts from different guns with different fill pressure.

But the valve and retainer screws are the weak link and not the tube itself?
The Disco and Maximus tubes are  equal in strength?

the tubes are the same strength and in both models the valve pinning is the weakest link..

[anti-squirrel]

This  project excites and intrigues me.  I like the purpose of this type of build, and seeing a bunch of fun Lego bits come together with a little elbow grease in a pellet delivery package just shows why Crosman deserves our money.

[KnifeMaker]

It's a shame that it is hard to use a Maximus barrel in this project, as it is in a Mrod. As the Maximus/new barrel from Crosman is Vastly superior in the accuracy department.

I would love to see the New Barrels come to the Mrod and Prod lines. I understand that the New Mrod FT does have the new barrels.

I too, mostly  due to severe back issues, very much enjoy and appreciate the lightweight of the Maximus.

I have opened the valve port, tp, and barrel port, and am very pleased with the results in the Maximus. It is exactly where I want it with JSB 18's
It was at 760 fps factory, and now at 890's with the mod's.  With the adjuster for the hammer spring I picked upo from Discos R Us, it will easily go higher. And can be turned down just as easily for the CPL's.

Knife

[39M]

So, there is no modding required to mount the Mrod barrel to the Prod receiver?

[FuzzyGrub]

Michael,

You could, but it would need to go to a machinist.  They will cut about 1/2" off the breech end and machine it for the prod tp style and location, along with leade and o-ring groove.  Talk to rocker1 if you are interested in doing that.  That is where the custom length shroud will come from.   

[FuzzyGrub]

So, there is no modding required to mount the Mrod barrel to the Prod receiver?

I have done that a few times.  It takes minor modification to fit.  Mostly it is the two set-screw and shroud mount flats have to be filed into barrel at the different locations.  If the mag is too tight, might have to take a little off the breech end of barrel.  Somewhere here there is an old thread on GTA when I first did it, with pics. 

[FuzzyGrub]

Just received a UPS notice, parts should be at the house, end of day Wednesday.   

[JohnnyD143]

Interesting project!

Curious what your goals are. And why the Prod valve instead of the Disco or.Maximus? Higher shot count maybe?

Two of the Prod breech screws thread into the valve.   I don't believe the maximus or disco valve have enough material in that area.  Even if they did, getting it right with DIY caveman tools would be a challenge. 

It will be the mate to this rifle:



It will start off life as a 22 cal, because that is what barrel and bolt I have.  Plan would be to go to 177 cal (waiting for F&T barrel) and would probably get a regulator at that time.  Mrods are about as heavy a gun as I'd like to carry, but prefer something lighter.

What are the specs on that beauty?

[FuzzyGrub]

What are the specs on that beauty?

That has a custom airtube by Jim at MM, and a Blaster stock from Disco R Us.   A little shorter than a disco or maximus tube, otherwise the same as what was planned for this.  The key is the much more affordable tube from crosman.

Please Note: In this picture the Prod breech is shimmed and uses a Mrod shroud.  It currently does not have the riser and has a Prod dia shroud followed by LDC.  That worked better and got the cheek weld lower and more manageable. 

[39M]

How much weight do you expect to save over a Synrod?

[FuzzyGrub]

How much weight do you expect to save over a Synrod?

My guess would be that the mods would only add 8-12ozs to the maximus.   

My 25 cal Synrod with a simmons 44 mag scope is 9.8lbs.  My 22 cal Mrod with BSA scope is 10.2lbs.  The Blaster with a Leapers scope is 8lbs.  2lbs is allot, and probably more with the max syn stock. 

[StevenG]

Very cool idea.

[KnifeMaker]

Good Looking!

I do enjoy the feather weight of the Maximum Stock. One of the things that sold me on the gun. That, and the Anschutz/CZ .22 pb style stock.

Knife