My Marauder 25. I need help

My Marauder 25. I need help

Joined: October 17th, 2016, 7:38 pm

November 9th, 2017, 9:22 pm #1

Goal: with a 25.4 grain pellet. 40 ft lbs. That equals about 850 fps.

Here is what I've done so far:
1. Installed a heavier hammer spring. Max speed 900, but terrible power curve with
only 10 good shots, averaging 875fps.
2. Installed a Lane Mk8 regulator. Max speed 750
2. Added an FFH. Max speed 750
4. Replaced the TP with a piece of tubing. Max speed 750.
5. Replaced that valve spring with a lighter one. Max speed 750
6. Added a Lane regulator extension tube for an additional 10cc volume. Max speed
750.

As I see it I have 3 options left
1. Increase the regulator pressure.
2. Increase the TP hole in the valve.
3. Increase the TP hole in the barrel.

If any of that works remove the 10cc extension and see what happens.
I hope someone has some other suggestions?
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Joined: May 6th, 2013, 6:24 pm

November 9th, 2017, 11:42 pm #2

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Joined: October 17th, 2016, 7:38 pm

November 10th, 2017, 12:39 am #3

Goal: with a 25.4 grain pellet. 40 ft lbs. That equals about 850 fps.

Here is what I've done so far:
1. Installed a heavier hammer spring. Max speed 900, but terrible power curve with
only 10 good shots, averaging 875fps.
2. Installed a Lane Mk8 regulator. Max speed 750
2. Added an FFH. Max speed 750
4. Replaced the TP with a piece of tubing. Max speed 750.
5. Replaced that valve spring with a lighter one. Max speed 750
6. Added a Lane regulator extension tube for an additional 10cc volume. Max speed
750.

As I see it I have 3 options left
1. Increase the regulator pressure.
2. Increase the TP hole in the valve.
3. Increase the TP hole in the barrel.

If any of that works remove the 10cc extension and see what happens.
I hope someone has some other suggestions?
Hoping for something less expensive. Something I can do myself.
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Joined: May 6th, 2013, 6:24 pm

November 10th, 2017, 1:57 am #4

Without some type of valve work i don't think 1,2,or3 will get the power you're looking for. Good place for Mrod info: MarauderAirrifle.com. Check out the .25 section.
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Joined: December 3rd, 2012, 4:24 pm

November 10th, 2017, 10:16 pm #5

Goal: with a 25.4 grain pellet. 40 ft lbs. That equals about 850 fps.

Here is what I've done so far:
1. Installed a heavier hammer spring. Max speed 900, but terrible power curve with
only 10 good shots, averaging 875fps.
2. Installed a Lane Mk8 regulator. Max speed 750
2. Added an FFH. Max speed 750
4. Replaced the TP with a piece of tubing. Max speed 750.
5. Replaced that valve spring with a lighter one. Max speed 750
6. Added a Lane regulator extension tube for an additional 10cc volume. Max speed
750.

As I see it I have 3 options left
1. Increase the regulator pressure.
2. Increase the TP hole in the valve.
3. Increase the TP hole in the barrel.

If any of that works remove the 10cc extension and see what happens.
I hope someone has some other suggestions?
You already had the power before the regulator, with what you have mentioned I would turn up the regulator. More power almost always means less shots. Also check the transfer port screw to make sure it's opened up all the way.
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Joined: January 5th, 2012, 9:45 am

November 11th, 2017, 12:24 am #6

Goal: with a 25.4 grain pellet. 40 ft lbs. That equals about 850 fps.

Here is what I've done so far:
1. Installed a heavier hammer spring. Max speed 900, but terrible power curve with
only 10 good shots, averaging 875fps.
2. Installed a Lane Mk8 regulator. Max speed 750
2. Added an FFH. Max speed 750
4. Replaced the TP with a piece of tubing. Max speed 750.
5. Replaced that valve spring with a lighter one. Max speed 750
6. Added a Lane regulator extension tube for an additional 10cc volume. Max speed
750.

As I see it I have 3 options left
1. Increase the regulator pressure.
2. Increase the TP hole in the valve.
3. Increase the TP hole in the barrel.

If any of that works remove the 10cc extension and see what happens.
I hope someone has some other suggestions?
With JSB Kings. I've since taken apart and modified some things while making my own FFH so unfortunately I can't be of more help but you should be able to get where you'd like to be
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Joined: May 6th, 2013, 6:24 pm

November 11th, 2017, 1:45 am #7

That's pretty sweet power level for stock rifle.
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Joined: January 5th, 2012, 9:45 am

November 11th, 2017, 7:12 am #8

I can't really try again since I drilled the threads out of the hammer for the FFH but curiosity has definitely taken over after mentioning this
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Joined: November 15th, 2007, 4:52 am

November 14th, 2017, 12:49 am #9

Goal: with a 25.4 grain pellet. 40 ft lbs. That equals about 850 fps.

Here is what I've done so far:
1. Installed a heavier hammer spring. Max speed 900, but terrible power curve with
only 10 good shots, averaging 875fps.
2. Installed a Lane Mk8 regulator. Max speed 750
2. Added an FFH. Max speed 750
4. Replaced the TP with a piece of tubing. Max speed 750.
5. Replaced that valve spring with a lighter one. Max speed 750
6. Added a Lane regulator extension tube for an additional 10cc volume. Max speed
750.

As I see it I have 3 options left
1. Increase the regulator pressure.
2. Increase the TP hole in the valve.
3. Increase the TP hole in the barrel.

If any of that works remove the 10cc extension and see what happens.
I hope someone has some other suggestions?
And i'll be impressed if you can do it with a regulator. I tried that with mine and even with 2000psi working regulated pressure i couldnt get 40fpe. There wasn't enough regulated air per shot in the plenum between the regulator and/in the valve.

I'm pretty sure its possible of you increase the plenum size and open up the transfer ports but I came to the conclusion there wasn't enough shots in the Mrod to be worth the trouble at 40fpe.

All that said, I'd love to hear of your success if you pursue it.
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