Maximus Prime

[imadunatic]

I am pretty sure a person could use secure a prod valve in a disco tube using the stock valve screw holes. You would just have to drill a new t-port in the tube. The Breech would sit a little bit forwards from the end of the tube.

Which I believe would also change your hammer throw? Is there enough bolt travel on the stock PROD breech to accommodate sliding it forward/back in relation to the trigger sears? I definitely think this is further down the rabbit hole than I'd want to go (at least on my 2400 HPA conversion).

[Matt15]

I am pretty sure a person could use secure a prod valve in a disco tube using the stock valve screw holes. You would just have to drill a new t-port in the tube. The Breech would sit a little bit forwards from the end of the tube.

Which I believe would also change your hammer throw? Is there enough bolt travel on the stock PROD breech to accommodate sliding it forward/back in relation to the trigger sears? I definitely think this is further down the rabbit hole than I'd want to go (at least on my 2400 HPA conversion).

Cut the extra off the tube. You might have to use a dremel to lengthen the hammer pin slot.   

[Rob M]

wouldnt the slot be longer on the disco/ maximus tube? Mayeb using the p-rod spring with the disco hammer?

[imadunatic]

I guess you just spend the extra $26 and use the maximus tube. Or, if one was so inclined, it looks like you could potentially redrill the 2400/disco tube for the new valve locations knowing they almost overlap. Joe posted pics over on the guild showing the specific differences between the 2 valves, and the direction that the screws move means the thin section between the existing discovery screw clearance in the tube and the screws required to fit a PROD valve would not be in the direction of pressure; HOWEVER, I have no idea what the result would be if this was ever accidentally overloaded. Personally, I'd want to do a pressure test and make sure all was safe.

Since those pics show that the transfer port are in the same spot, I don't really see why you couldn't just use the discovery valve and drill/tap for the PROD breech screws?

I'm guessing this is the fella that mated the PROD breech to the disco: http://www.gatewaytoairguns.org/GTA/index.php?topic=100696.msg945401#msg945401

That being said, John, sorry for hijacking your thread!

[FuzzyGrub]

I am pretty sure a person could use secure a prod valve in a disco tube using the stock valve screw holes. You would just have to drill a new t-port in the tube. The Breech would sit a little bit forwards from the end of the tube.

You would have to cut the hammer and trigger sear channels longer.  Not sure where the trigger pack mounting holes will end up.  The big killer can be the gauge port.  The valve would block it from being in correct position.   I can look more closely at it tonight, but just off-hand this approach would be even more work and higher probability for other issues. 

[FuzzyGrub]

I guess you just spend the extra $26 and use the maximus tube. Or, if one was so inclined, it looks like you could potentially redrill the 2400/disco tube for the new valve locations knowing they almost overlap. Joe posted pics over on the guild showing the specific differences between the 2 valves, and the direction that the screws move means the thin section between the existing discovery screw clearance in the tube and the screws required to fit a PROD valve would not be in the direction of pressure; HOWEVER, I have no idea what the result would be if this was ever accidentally overloaded. Personally, I'd want to do a pressure test and make sure all was safe.

Since those pics show that the transfer port are in the same spot, I don't really see why you couldn't just use the discovery valve and drill/tap for the PROD breech screws?

I'm guessing this is the fella that mated the PROD breech to the disco: http://www.gatewaytoairguns.org/GTA/index.php?topic=100696.msg945401#msg945401

That being said, John, sorry for hijacking your thread!

No, issue with discussing the disco tube.  It is the reason I went with the max, because I didn't see a relative easy way to do it with disco.   If there was, be glad to hear about it. 

Yes, that is the build I was talking about.  He does excellent work.

I also agree that the load bearing side of the valve screws would be opposite of the screw hole that may break into.   Is that good, don't know. 

[Buldawg76]

John
I just looked closer at my Maximus for interference between the end cap and the stock and it does have just a very slight interference at the lower portion of the stock in the 4 and 8 o clock positions. I will be removing the action to relieve the stock on mine in those areas. It appears that action is possibly sitting just a smidge high at the rear in the stock and the end cap has forced some of the plastic of the stock outward in those areas.

Thank you for mentioning that as I did not catch it when installing the action in the stock since its so slight it was not noticeable till you mentioned it.

Mike 

[FuzzyGrub]

For the mrod trigger, I think I'll add the 3rd screw for better integrity.   I'll have to do a small relief in the valve like the mrod has.  What did bother me is the standard stock lug.  It is same for disco and max.  That is a very small diameter screw which holds the stock and stock screw.   I'd think it would be very easy to strip out.   Someone has probably come up with fixes for this already, so thought I'd ask. 

[dmeguy]

What did bother me is the standard stock lug.  It is same for disco and max.  That is a very small diameter screw which holds the stock and stock screw.   I'd think it would be very easy to strip out.

Funny you should mention that. I've only had my Disco a few months and the lug hole is already stripped. It appears the lug was machined slightly too long, my valve has a definite indention from the end of the lug. I guess I'll add an airtube and lug to my next Crosman order.

[Buldawg76]

I had the stock lug hole strip out in one of my Disco tubes as well and it was hitting the valve also. I was able to fix it with a similar type standoff part t had in my nut and bolts drawer. it was metric threads with 6mmx1.0mm pitch for the stud and lug so I carefully taped the tube to 6mmx1.0mm and ground the stud to clear the valve and found a beveled screw in 6mmx1.0mm to hold the stock in place and is still doing good now.

It was similar to this standoff and I believe this would work as well.

https://www.mcmaster.com/#92499a505/=16l1tf5

Mike

[dmeguy]

Thanks. I'll check the local hardware store and try that first.

[FuzzyGrub]

It looks like the original was 8-32 male and 1/4-20 on the female. 

The male length is 7/16", along with hex size and length. 

Measuring the thickness of the trigger pack and tube, shouldn't come close to hitting valve, since it is in that relief area. 



I think I'll stay with the existing, and make sure it is blue loctited in.  Still going to do 3rd screw as long as valve has some roon for the clearance.

[Buldawg76]

It looks like the original was 8-32 male and 1/4-20 on the female. 

The male length is 7/16", along with hex size and length. 

Measuring the thickness of the trigger pack and tube, shouldn't come close to hitting valve, since it is in that relief area. 



I think I'll stay with the existing, and make sure it is blue loctited in.  Still going to do 3rd screw as long as valve has some roon for the clearance.

Yea if the tube is not stripped I would Loctite it and just tighten enough to keep the trigger pack tight and shorten so it is not hitting the valve.. My tube was stripped and I did not want to wait for a new tube to be mailed to me. It worked out good.

Mike

[FuzzyGrub]

John
I just looked closer at my Maximus for interference between the end cap and the stock and it does have just a very slight interference at the lower portion of the stock in the 4 and 8 o clock positions. I will be removing the action to relieve the stock on mine in those areas. It appears that action is possibly sitting just a smidge high at the rear in the stock and the end cap has forced some of the plastic of the stock outward in those areas.

Thank you for mentioning that as I did not catch it when installing the action in the stock since its so slight it was not noticeable till you mentioned it.

Mike

Mike,

I did a test fit tube to stock, with and without an end cap.  Yes, it will take a little trimming of the stock.  Dowel rod or dremel won't be hard.

[Maurice Davis]

Oh wow that trigger really fits🤔

[K.O.]

never been much of a Schnabel fore stock fan... to make it worse it looks like/is a plastic tulip...  worth it for the low price and light weight... just wish it looked like a disco stock...

[Buldawg76]

John
I just looked closer at my Maximus for interference between the end cap and the stock and it does have just a very slight interference at the lower portion of the stock in the 4 and 8 o clock positions. I will be removing the action to relieve the stock on mine in those areas. It appears that action is possibly sitting just a smidge high at the rear in the stock and the end cap has forced some of the plastic of the stock outward in those areas.

Thank you for mentioning that as I did not catch it when installing the action in the stock since its so slight it was not noticeable till you mentioned it.

Mike

Mike,

I did a test fit tube to stock, with and without an end cap.  Yes, it will take a little trimming of the stock.  Dowel rod or dremel won't be hard.

Yep I saw that today when I checked the fit and its not much at all that will need trimmed to clear the cap.

The Mrod trigger fits real good in the stock, so what trigger housing are you going to use. Will you be installing the challenger trigger guard like most do or are you going to try to fit another more conventional guard in place instead.

Did you use any kind of shim under the Mrod trigger or change out the sear with one that has a lower profile. If not then how will you compensate for the difference in tube thickness.

Mike   

[KnifeMaker]

I'm exactly the opposite. Always Loved the Anschutz/CZ Sporter Stocks, and the Max. is very close. On the other hand, I always found the Disco stock to be extremely cheap, and poorly designed. Butt ugly to me. 

And exactly why different seats for different rears!

Knife 

[FamilyMan811]

Looking good grub ..  I stripped my stock lug installing my Mrod trigger kit today 

But have another lug on its way. Seemed like I had but 2 or 3 threads a best after spacer.. how was yours if you recall?

[FuzzyGrub]

The trigger pack was just mounted for the test fit.  No shims yet, but those are easy to make from plastic or thin brass washers.  Good point FM, those shims lesson the thread engagement.     When I test fitted on the Prod stub, the threads barely made it to the inside of tube.  My search on MC did not find the oem size or one just slightly bigger.  It won't be the first sear I had to file.  Just can't go back on a Mrod. 

I'm not a big fan of the challenger trigger guard.  I haven't decided exactly what I'll do yet.  Try making one or find another crosman one that might fit.  2 1/2" pipe hanger?   

As far as the stock, it is not bad.  It is sturdier in the fore grip than the Mrod syn stock.  The mrod you can twist back and forth, but it is also floated to the air tube.  This, the air tube snaps into.  Found the secret to remove the butt plate (remove sling stud).  It is hollow as I thought.  It will need some form of cheek riser for the higher breech, and I like to stuff/pack with Styrofoam peanuts, to lesson that hollow sound.  I believe it will be balanced, but if muzzle heavy there is room for counter weight.