Mrod shroud touching barrel band

[Oldfatguy]

Now I’m on the third Mrod, first two returned. First leaked badly.Problem with the 2nd one was the shroud firmly in contact with the bottom of the barrel band. Not very accurate. 3rd one was close but not touching - at first. After about 100 shots last groups not as good as first ones. Shroud was/is touching bottom of barrel band . Took scope off & loosened both set screws clamping the barrel in the breach block. Tightened rear one, not touching. Tightened front ss and could see the shroud moving down & touching barrel band. Anyone have any success correcting this problem?

OFG

 

[Bigragu]

Go get yourself a hill airguns barrel band that replaces the factory band. It even has a pic rail on the bottom to attach accessories if you wish. My first Pcp was the Gen2 marauder stuffed full of hill parts along with that band, and I always told myself if I ever invested in another marauder and limited that gun to just one aftermarket mod, it would be that hill band. Fits snugly onto the shroud, helps with accuracy, and best of all, I can lean my barrel against a corner wall and know my point of impact won’t change

 

[rcarlisle]

Tighten the barrel set screws until you can just feel them make contact in the grooves on the barrel, then try rotating the barrel left and right a little as you snug it up the rest of the way. I've had the set screws tightened down when that flat was not quite level and ended up with a loose barrel after a few shots. Just a possibility...

 

[AlanMcD]

While I really like the platform, I have always found the interface between the shroud system and the thin flimsy barrels to be maddening in the Marauder. The idea of a “free floated” barrel is great, but the Marauder barrels are so thin for their length – especially the .22 cal, which has a metal thickness of just a bit over 0.1” – that any “lack of repeatability” in the shroud system is going to impact the repeatability of the location of the free floated barrel.

The Hill mount (and other ideas like o-rings in the front shroud mount) can help, but they do eliminate the “free floated" nature of things. I found I could not do that as I both shoot regulated over a large pressure range (which leads to more pressure tube deflection) and use aluminum tubes that I bought from JSAR years ago (which move even more than the steel tubes do).

For me I found the best result was to move the rear shroud mount forward a bit, so that the shroud does not come into contact with the breach (I leave a gap of 1-2 millimeters). Then I fully tighten the shroud to the mount, but then back it off by about half a turn leaving it loose. I also put a small index mark (aka a scratch) on top the shroud so that I can always position it in the same place, and can easily verify that it is where I want it to be. This has worked very well for me.

The advice on how to tighten down the barrel is excellent too. Just make sure you check you mag fit when you do this, as fore-aft adjustment can impact how easily they go in and out. And also be sure not to over tighten the grub screws, as the barrel is insanely thin where the flats are cut (having removed about half of the already thin material) – it is easy to permanently dimple the barrel, and even before you go that far you can distort the inside. It is best to just lightly snug them up while using removable thread locker on the grub screws to keep them where you set them.

 

[elh0102]

I had an issue with the barrel band on a Daystate Revere. The barrel shroud was free floated within the band, but the clearance was so small that even normal handling of the rifle caused it to rattle against the band. Since the band was not in contact, the obvious question was, why have it? So, I removed it and it worked great. That said, I have no experience with your rifle, and removing the band might not be advisable. The Daystate barrel, and its mounting system are both sturdy, and I saw no need in keeping the band, as it was mostly an aesthetic feature. Lastly, have you ruled out a dirty barrel as the problem? I'm a little surprised that the contact you describe is adversely affecting accuracy.

 

[pnwairgunner]

I agree with recommending the Hill barrel band. It’s one of the best things you can do for your Marauder. You’ll lose no accuracy at all, in fact by eliminating the variations in the movement of the shroud and barrel from shot to shot and from day to day, you’ll end up having a MORE accurate rifle. The free floating barrel is only a good thing if the barrel is stiff and solidly mounted- as in the Evol. Otherwise you have flimsy flexible material that is always being bumped or nudged this way or that way.
No more POI shifts with your marauder is a good thing.

 

[Oldfatguy]

Thank all of you for your suggestions. No wind this AM so shot 2 groups at 25 yards w/o the shroud (top) and 2 groups WITH the shroud & backed out 1/4 turn CCW (bottom). Tightened the rear barrel set screw to about 18 FP. Ran the front ss in till it just made contact with the barrel. Shroud not touching barrel band. I think I can live with that.

OFG

 

[Deltaman]

I had an mrod for several weeks and it just didn't work out for me so I sold it. I kept the hill barrel band and have it available to anyone who needs it. A must have for your mrod. Message me if you're interested!