Another Regulated P-rod

Jump to latest Follow Reply
ajshoots wrote: "The Gaska barrel will slow the gun down some. The above gun I worked on would not produce the same velocity as mine, and the only difference was his bore is much tighter than mine".

You are right. I tested the Prod OEM barrel today and got an average of 725 fps (10 shots), compared to the 695 fps from the JG barrel. But the accuracy...no comparison.

30cal wrote: Motorhead hangs out over at Marauderairrifles.com. He makes and sells a light weight hammer for low to moderate power tunes for Mrods. Not sure about Prods. To get high power from a regulated gun you need more plenum volume. In my case I used a Tim hill valve and gauge block which has more volume than stock and a Huma .25 cal regulator which again has more internal air volume than the one for the .177 and .22 version. Its putting out 39 FPE for 16 shots on the reg. I don’t know if there is an easy way to get more volume in a regulated Prod as I don’t have one. But with the small air tube you would only get a handful of shots per charge.

I contacted Motorhead, but he does not sell LW hammers for Prods as individual parts, but as a component of a complete tuning work. I made a rustic aluminum light hammer (25 gr.and 34 gr. trials) and after using it with different springs and adjustments, could not get better results than with the stock hammer. Don't know why... Anyway, in pursuing the elusive 31 shots @18.8 fpe shot string, my best results so far have been achieved with the stock hammer, all ports opened to 9/64", weaker valve spring (no rate), 1 5/16"/.047" hammer spring, and HT=0; HS=4. Still stuck at 20 [email protected] fpe. with an es of 10 fps. I also got a string of 16 shots @19.8 fpe with the same setup but increasing the HS, of course. This tune is similar to the one posted in the Yellow Forum (see below), if you consider my slower JG barrel. I am running out of options...but having fun and learning. If anyone finds out how to achieve the [email protected] tune, please let me know!


DaBinChe wrote: I have the Hill valve and also the Huma regulator. Guess I should of got the Hill kit for regulated instead of the 25# kit. The Huma comes with a plenum that takes over the guage block as not to loose volume. The Hill 25# kit also comes with some o-rings for the buffer mod. With a regulator, will the buffer mod do anything?I think I’m gonna have to abandon wanting to make the p-rod a 20fpe for head shots on bandits…and just make it a rat gun only. If so then I’ll lower the power to sub 10fpe…but of course that is dependent on the pellets and what they like. I prefer to stick with crossman premiers for lower cost and easy access at wallyworld.

See this link: http://www.network54.com/Forum/79537/thread/1448492911/last-1448538857/Expand+Thread
Using a buffer with three o-rings. Sixteen shots at 21.8 fpe, with an spread of 3 fps (if you have a stock barrel). Not bad! The HUMA regulators for the Prod are proving to be very consistent.
 
Upvote 0
"ajshoots"I am new to regulating these guns, but I am rather certain that a regulator is not going to allow the gun to reach its potential max velocity. Without the regulator, I had the above gun shooting in the 840fps range with 15gr pellets. I didn't run a full string, but it will make alot more power unregulated, but the shot count will be about 8 shots or less. Being new to regulated prods, I have no clue what the potential max is?? All I can suggest is to increase the volume in the valve, by opening up the inner body, the valve cap, and maybe opening the throat up will also help to increase regulated power? If you want max power without the regulator, you want a large open flowing valve with as big of ports as the gun will handle, but again that means very few shots and probably a wide velocity spread on those few shots. Either way, most of the valve work really needs to be done on a lathe. You could get away with a drill press maybe, but you risk ruining the valve. 

And also, I would be very curious as to the full details of how that gun got 31 shots at 18.8fpe!! If I were you, I would contact a fellow named Scott. He goes by the name Motorhead on some forums. I am unsure if he is a member here?? He knows regulated prods and marauders better than anyone else!!
Click to expand...
I emailed Huub Andriessen, the person that originally achieved the 31 shots @ 18.8 fpe. He is a very nice guy and responded to my email in a matter of minutes. In case someone is interested, this is what he did to get the string:

"Hello miguel,

I have had a p-rod here to make and test the reg.
I only opened up the valve port and transferport.
Rest is nothing more or less as adjusting hammerspring and hammer stroke.
If i recall i did not do much with the stroke lenght.

Try not to much hammerspring tension, it will get huge air consumption.
Listen carefully to your pistol. More noise is more air use.

I thougt i had between 125-130 bar.
If the pelletspeed is ok and shotstring peaks at end then you have to much reg pressure and lower this and lower hammer spring.


My first shotstring was 15 shots. Second i readjusted the hammer and got 24 the last ones you have seen.

When you adjust the hammer you should see significant speed change with only bit adjustment.
If speed climbs very low the you have too much hammer spring and you have to get bit more reg pressure.

Trial and error
I think it is just "fingertip feeling"

Cheers huub"
Verstuurd vanaf mijn iPhone

He opened the ports to 3.5 mm, as indicated in the installation instructions of the regulator. For now, I'll keep using my current tune. I'll try this one after Christmas. 
 
Upvote 0

I emailed Huub Andriessen, the person who originally achieved the 31 shots @ 18.8 fpe. He is a very nice guy and responded to my email in a matter of minutes. In case someone is interested, this is what he did to get the string:

"Hello miguel,

I have had a p-rod here to make and test the reg.
I only opened up the valve port and transferport.
Rest is nothing more or less as adjusting hammerspring and hammer stroke.
If i recall i did not do much with the stroke lenght.

Try not to much hammerspring tension, it will get huge air consumption.
Listen carefully to your pistol. More noise is more air use.

I thougt i had between 125-130 bar.
If the pelletspeed is ok and shotstring peaks at end then you have to much reg pressure and lower this and lower hammer spring.


My first shotstring was 15 shots. Second i readjusted the hammer and got 24 the last ones you have seen.

When you adjust the hammer you should see significant speed change with only bit adjustment.
If speed climbs very low the you have too much hammer spring and you have to get bit more reg pressure.

Trial and error
I think it is just "fingertip feeling"

Cheers huub"
Verstuurd vanaf mijn iPhone

He opened the ports to 3.5 mm, as indicated in the installation instructions of the regulator. For now, I'll keep using my current tune. I'll try this one after Christmas.
modify_inline.gif
 
Upvote 0
You must log in or register to reply here.
Top Bottom
Back
Home
Forums
Resources
Menu