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Benjamin Marauder (Mrod), strip, teardown, disassemble and operation

Well, while I’m waiting for the BSA Super 10 receiver to show up, and feeling a bit more ambition lately, I shifted attention to my Benjamin Marauder in .177 cal.  I got this air rifle from Mac1 airgun shop a few months after the marauder was introduced.   It was originally in .22 cal, but I switched it over to .177 with parts from Crosman when I decided to go pcp for field target competition.   Now that the FT season is about over, I thought I’d tear it down, clean it, replace o-rings, and get my adjustments in place for winter practice.  My bi-annual airgun check-up, so to speak.

In this video, you may notice that I took out the pressure gage and block, and put a regulator in its place in the airtube using the gage opening as the regulator atmospheric air hole.  I got the regulator from Airgun Exporter a few years ago, and it still seems to work without any problems, so I’m not going to make any adjustments to it.  It puts out 130 bar to the valve, or about 1875 psi, which is a bit on the hot side, but leaves lots of room for the other adjustments.  I was getting about 40 shots per 3000 psi fill, at about 15 ft. lbs.  I wasn’t too concerned about having enough air on match days, since there is usually air at the match site.  But, I think I can tune it to get a little more velocity and ft. lbs., and  yet maintain that same shot count.   In terms of accuracy, this gun likes the JSB Exact 8.4 gr or Crosman Premier heavy pellets best.

Tuning the marauder isn’t particularly hard, but it does require quite a bit of effort to get the rifle set up the way you want it.  And a chronograph is almost mandatory;  without it, you’ll have to shoot targets after each adjustment, consuming substantially more time and air.  A chronograph saves on both, and is a worthwhile investment for any marauder rifle of pistol owner.

As an alternative, there are a number of professional tuners out there who can set up a marauder to whatever specs you want, within the limitations of the airgun or even a bit beyond.  These guys have already put in time to figure out how to get more shots, more power, more accuracy, etc.  Unless you enjoy the tinkering part of being a marauder owner, can handle the sometimes frustrating and unexpected results, and have the time and inclination, you might be better off having your airgun professionally tuned, i.e., save your time and air for shooting instead of tuning.

This video is my method of stripping the marauder rifle, and also a bit of explanation of how the factory adjustments work.  I’m always open to better methods or tools or techniques, so feel free to offer any tips you might have.   I’ll follow this up with the tuning video as soon as I get time to put it together.

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