Mrod to Brod conversion

[PeaceMaker]

Have any of you guys converted your Mrod to a Brod? If so were your results better or worse? What bottle size did you use and what regulator psi did you go with? Should the pressure gauge block be removed?

I have a 25 cal Gen 2 Marauder .

 

[Eaglehorn]

I did one and it increased air capacity and shot count massively w/ a 480cc bottle. One thing to be conscious of is weight, so be careful with overall length. Reg PSI will depend on how large the plenum is and what kind of performance you're looking for. The gauge block should stay in place if you have a hole for the factory gauge for your pressure tube.

 

[bearair]

I've got two now. One in 22 and one in 30. The 30 gets 42 shot around 70 fpe with 44.75gr pellets and I'm thinking the 22 will get close to a 100 shots with 25.39gr pellets shooting 850-870fps. I'm still working with the 22 that's why I don't have a definite shot count yet. It will lighten your rifle up too. You can either get a short tube with the gauge hole or one without it. Definitely a worthy upgrade.

 

[Motorhead]

Second one built in the last 5-6 years This one as shown a .25 cal with a hybrid balanced valve and mostly custom everything else ... 58-60 fpe with pellets.

No gauge block ... BIG plenum ... Ninja adjustable @ 2200 psi ... 400cc 3K bottle, tho now wears a 480cc 4.5K CF bottle.





HAVE FUN !!!

Scott S

 

[ackuric]

Nope, I have not! But if I were to...



Aim for around 60-70 cc's of plenum available between your valve and reg plenum (cut down tube) if you want access to lots of power.



Mrod tube is roughly 15 cc per inch, so that is at least 3.5-4 inches of tube between where the fill assembly ends, and the gauge port begins



You should be able to keep regulator at or around 2k provided you port the valve to around 85% of bore, and of course, this entirely depends on your intended power output..



Pressure gauge block...Optional, but if using the stock tube you're best leaving it opposed to plugging it, that will be your regulated pressure gauge, and you can setup the bottle to show res pressure.

 

[Yo]

Nope, I have not! But if I were to...



Aim for around 60-70 cc's of plenum available between your valve and reg plenum (cut down tube) if you want access to lots of power.



Mrod tube is roughly 15 cc per inch, so that is at least 3.5-4 inches of tube between where the fill assembly ends, and the gauge port begins



You should be able to keep regulator at or around 2k provided you port the valve to around 85% of bore, and of course, this entirely depends on your intended power output..



Pressure gauge block...Optional, but if using the stock tube you're best leaving it opposed to plugging it, that will be your regulated pressure gauge, and you can setup the bottle to show res pressure.

THATS SPOT ON. You may even be able to get.sone decent results by starting at 80bar and work your way up with such a MASSIVE PLENUM. Yo!

 

[PeaceMaker]

My, biggest reason for the conversion is to shoot slugs on the heavier side 40gr+ with at least 5 good shots.

If I'm off base please let me know. Definitely not a backyard plinker, but hunting rifle 

Thanks for all of your input. God bless

 

[ackuric]

My, biggest reason for the conversion is to shoot slugs on the heavier side 40gr+ with at least 5 good shots.

If I'm off base please let me know. Definitely not a backyard plinker, but hunting rifle 

Thanks for all of your input. God bless

5 shots? You should be able to do plenty more than that with a bottled gun, provided you set it up to run fairly efficiently...

I'd hazard to guess you should be able to get near or over 20 shots shooting 40 gr at 950~ fps if you use a 480 cc bottle.


Heck, I could do more than 5 shots with my stock length tube marauder with 40 gr at 950 fps.



At the very least, your expectations are low...if you're not familiar with these kind of builds, just do your reading. I would stick to 60-70 cc's of plenum for your build as I mentioned above.

 

[bearair]

I agree as well. With a 500cc tank from a 286cc tube, I had the extension as well, I'm looking at going from 40 shots to possibly a 100. Not only will you be adding volume the pressure is almost 1.5 times what a tube can be filled to. If you went with a 500cc tank I wouldn't be surprised if you could get 30 to 40 shots. That will be dictated by the energy your looking for though. Looking forward to seeing this beast.

 

[T3PRanch]

Second one built in the last 5-6 years This one as shown a .25 cal with a hybrid balanced valve and mostly custom everything else ... 58-60 fpe with pellets.

No gauge block ... BIG plenum ... Ninja adjustable @ 2200 psi ... 400cc 3K bottle, tho now wears a 480cc 4.5K CF bottle.





HAVE FUN !!!

Scott S

Hey Scott where did you get your bottle block? I tried a JDS Airman but I did not like the safety factor it provided with too few screws to attach to the plenum tube!

 

[bearair]

New England airguns carries RAI drop blocks

 

[PeaceMaker]

I have a Tim Hill complete valve upgrade, I believe is his version one. I got a chrony so I'll get some numbers before I convert it.

 

[bearair]

That's a great idea and also write down your current settings so when you do the build you have a starting point.

 

[PeaceMaker]

Will do, thanks

 

[bearair]

It really helps, like today my .177 wasn't shooting right and then I noticed the hammer spring adjuster had backed itself off. It was a quick fix with some blue Loctite and my notebook. Everything is back to normal again.