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Marauder Gen 2 velocity question. (RESOLVED)

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maypo59

maypo59

Member
Nov 19, 2019
13
0
Kentucky
OK.. I have had a MRod for about a year. I didn't own a chrony until a couple weeks ago, after she got an Avenger. Bought a chrony, because the Avenger was advertised as being very adjustable. It Is.

But.. I made the mistake I guess, of mounting it on my Marauder .25, shooting the 25.39 King, lightest pellet I have, and most accurate by a smidge.

After watching 11teen videos, reading the manual 8 times and adjusting the "velocity screw" the hammer tension and the hammer travel, up down sideways, following several suggested settings on videos and blogs, airing to various pressures from 2200 to 3000 psi..

762fps average over 8 shots, is the best velocity I have seen. only 7fps spread, so it's consistent, but it's advertised as a 900fps gun out of the box in .25


suggestions?

Because I hate it when I search the web and find questions, much like whatever I am looking for, and the threads often just die, with no answer if anything worked or not..

I received a couple of barrel o-rings in the mail today. Some silicone grease and 1 placed in the rifle where it belongs. The bolt feels different then it used to, and I think ever did. Returned the hammer spring tension and hammer travel to where they were when I started, left the velocity screw at 4.5 turns (it was at1 turn initially) My POI came up 3/4 of an inch at my 25 yard zero, and a 10 shot string averaged 879fps with a 2.2 fps spread. It also does seem quieter, so guess she gets to keep the Sumo for now..

I think there is a possibility the rifle came without one, or it was lost VERY early in my ownership.. But all better now. Thanks for the help, recommendations, and guidance.
 
Do you have a bad transfer port seal or barrel o-ring? That can kill your velocity. I like to put a paper towel draped over the breech and then I test fire it. If the napkin moves then more than likely your TP isn't sealed a 100%. That can kill your velocity. Also you can open the barrel and get a larger TP as well. I personally have several of these rifles modded out so I disagree with the previous post. If you feel the need to soup it up check out Hill airgun. He offers a lot of aftermarket upgrades and he offers the 10 and 12# springs as well. Good luck and hopefully you get it tuned to the way want.
 
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Ok. Lets do the math here. Hill offers three types of kits. One a reg kit for about $387, one is a high performance kit for about $312, and another is a max power kit for about $325. With the cost of how much you bought your mrod, you could've bought a used fx wildcat, bobcat, or a streamline, or used cricket which will be regulated and have more power. I would understand if you are totally in love with this mrod and will never sell it but if you decide to sell your mrod, you will lose a lot of money. I personally see a used mrod cost about 300 and no more if nothing was done to it. Another 100 if it you did the works to this gun like added reg, valve, gauge block work, etc. On the other hand if you bought a cricket for 800 and you wanted to resell it, you could easily sell it with minimum lost. If you want your .25 mrod to have a higher shot count or have very high power, buy a different gun
 
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Ok. Lets do the math here. Hill offers three types of kits. One a reg kit for about $387, one is a high performance kit for about $312, and another is a max power kit for about $325. With the cost of how much you bought your mrod, you could've bought a used fx wildcat, bobcat, or a streamline, or used cricket which will be regulated and have more power. I would understand if you are totally in love with this mrod and will never sell it but if you decide to sell your mrod, you will lose a lot of money. I personally see a used mrod cost about 300 and no more if nothing was done to it. Another 100 if it you did the works to this gun like added reg, valve, gauge block work, etc. On the other hand if you bought a cricket for 800 and you wanted to resell it, you could easily sell it with minimum lost. If you want your .25 mrod to have a higher shot count or have very high power, buy a different gun
Click to expand...


I don't want "very high power".. I would like the advertised power. If I decide that a new gun is the answer, I already have a couple picked out.. LOL

But, this one should do everything I need, and at it's advertised FPE, kill what I need killed. My question was more along the lines of.. what am I missing on getting the rifle to do what it is supposed to do.. 1st string over the chrony was 640fps.. for literally 1/2 the advertised out of the box energy. Messing with all of the available adjustments, only gained me 120fps, not the missing 310...

Oh, and that style of "math" works on cars, motorcycles, bicycles, pretty much everything. I know how that works. Thanks.

 
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Throw away the crony and then life can go back to normal as It always did.

Taping up regulator Manometers helps relieve undue stress as well.

Main thing the gun is accurate screw the velocity.
Click to expand...


20 years combat arms soldier.. 40 years reloading for smokeless powder and nearly 50 years shooting black powder.. I can't throw the chrony away.. LOL..

But I do get the spirit of what you mean.

EDIT.. Plus, we have some spinners set up at 40 yards, and I can't let her .22 Avenger hit them harder then my .25.. my mind won't have that.. LOL
 
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Do you have a bad transfer port seal or barrel o-ring? That can kill your velocity. I like to put a paper towel draped over the breech and then I test fire it. If the napkin moves then more than likely your TP isn't sealed a 100%. That can kill your velocity. Also you can open the barrel and get a larger TP as well. I personally have several of these rifles modded out so I disagree with the previous post. If you feel the need to soup it up check out Hill airgun. He offers a lot of aftermarket upgrades and he offers the 10 and 12# springs as well. Good luck and hopefully you get it tuned to the way want.
Click to expand...


I have not noticed any puff or feel of air, and certainly no noise or hiss when firing, but I will in the morning, put a tissue over the breech area and shoot a couple shots to see.. Thanks.
 
Upvote 0
Do you have a bad transfer port seal or barrel o-ring? That can kill your velocity. I like to put a paper towel draped over the breech and then I test fire it. If the napkin moves then more than likely your TP isn't sealed a 100%. That can kill your velocity.
Click to expand...


The single ply of tissue.. disintegrated... Rifle was loaded, and cocked, scope and magazine removed, paper laid over the breach area.. I wish I had taken video..

EDIT: after having a better idea of where the problem seems to be, It would appear I need a probe seal. It would seem the Benjamin part number is 105-006. Does anyone happen to know what size that actually is? or if it can be purchased at say, ACE hardware? Not having the o-ring in hand makes it hard to compare.. and again, thanks to all who responded.
 
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The Benjamin/Crosman part number is 130-036 for the breech o rings (transfer port), you need two (2) and they are NOT readily available at a hardware store. They have a square shoulder. You can get them from Crosman, EBay or Hill Airguns. The barrel o ring that seals the probe in the breech is the one you posted the part number for, 130-036. That is normally the one that goes first. 
 
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Yes, the o-ring that the bolt/probe goes through. It's easy to see and get to, and is missing. Found a video that showed exactly where to look, and exactly what I was looking for.. Had to remove the scope to get a good look, and to get access to the breech opening.

And thank you to all who suggested Tim Hill, In today's world, getting a quick and concise answer form someone online at a company can be frustrating. Nothing but good vibes and timely contact with him. I seriously doubt I will find the need to pump up the volume with this rifle, but if I do, it will be with a Hill kit. (I have to admit, her Avenger with the adjustable regulator.. it is a pretty nice feature.)

But like I said above.. I just want it to attain it's stock potential. 
 
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