Marauder .22 shoots great without shroud, but....

[shibumei]

Well I've read about all kinds of issues and fixes with the .22 Marauder but I am stumped and hope someone has resolved this one before.  With no shroud, I'm getting consistent ragged groups.  With the shroud, groups widen big time.  What I have tried is:

No Barrel band ( better but no cigar)
Shroud on with no baffles or end cap
Shroud on with just end cap.
Swapped shroud from .25 Marauder and band.

Since gun is shooting great without the shroud,can I assume this has nothing to do with the barrel?   Any suggestions GREATLY appreciated.   

[Sfttailrdr46]

I have the shroud free floating. You may also want to inspect the end cap and baffles for signs of the pellets clipping the baffles or end cap since this is often a source of scatter gun groups

[shibumei]

Well I got so frustrated.  I bent the barrel until I could see the same symmetrical amount of daylight between the shroud and band.  It's looking really, really promising so far but I can't understand bending the barrel made such a difference over removing the barrel band all together which I tried.

Oh, and by the way Don, I think I now have your old Regal in .25 via Matt..  Should be here tomorrow

 

[Sfttailrdr46]

Well I got so frustrated.  I bent the barrel until I could see the same symmetrical amount of daylight between the shroud and band.  It's looking really, really promising so far but I can't understand bending the barrel made such a difference over removing the barrel band all together which I tried.

Oh, and by the way Don, I think I now have your old Regal in .25 via Matt..  Should be here tomorrow

You won't be disappointed that rifle is a tack driver and makes decent power

[triggertreat]

It could have been a TP alignment issue, a bent or offset breech issue , or breech screw tension issue, too.  You can watch the barrel alignment compared to the  barrel band as you tighten down the breech screws.  I always loosen the barrel band and tighten it down last after letting the shroud settle in place.  I do use an O-ring to de-float the barrel, and don't want any uneven stress on any spot of that O-ring.  I also use a 1/2" diameter WAR HF barrel which helps stability and is awesome.

[Ribbonstone]

Keeping it simple, are only three things that come to mind.

Shoots well without the shroud...shoots much worse with the shroud.

1. Could be the shroud is not aligned with the bore.  Doesn't take a full-on smack into a baffle or end cap, just a slight pellet touch would be more likely.

2. Could be that the shroud is aligned when you check it before shooting, but gets out of alignment during the shot...basically the barrel and shroud are acting like independent elements, vibrating in different patterns.

3. (kind of goes with #2): shroud is a bit loose to the barrel.  Randomly vibrating stuff (shroud/LDC/Brake/whatever) hanging on a barrel is just deadly to accuracy even when it doesn't actually clip the pellet.

Don't have any fast sure-cures....don't even have a Marauder,but the same rules apply to any shrouded PCP.

I would go to the effort of taking the baffles and end cap off the shroud, cleaning them, and coloring them with pencil(nice layer of graphite). Assemble...shoot...take apart again and look for "snail tracks" in the graphite.


Would also try a bare-barrel (no shroud) and put a weight on the barrel (a 1 foot length of electrical solder wrapped like a snake around the barrel will do) and see if just weight causes poor grouping (although I'll give you the group will likely land in an unexpected place).

[bear air]

I read somewhere that you want to make sure the o-ring around the air stripper has a fair amount of silicone lube on it. I'm not really sure if this will make a difference but hopefully you figure out the problem. I bought a 22 caliber marauder over Christmas and the factory barrel seems ok but I've got one coming from Jim at WAR. His barrels are accurate. I have one in my 25 armada and I cant wait until it warms up and I can see how it does at 50 yards and maybe a 100 as well. You'll have to keep us posted on your findings.

[avator]

You didn't mention the location of the de-pinger inside of the shroud.... ??
I'm talking about this guy...

[avator]

A trick to installing it is to loop a length of fishing line around it and center it in the tube. Once centered you can just pull the line out. It dosen't hurt to tie it off and tuck it inside the tube so the depinger can be just pulled out in the future.

[AlanMcD]

First, the deginger goes in the air tube, not the shroud, so that can't be a factor (sorry, Bill) . . .

I always found that the the tightness of the shroud, as screwed onto the rear shroud mount, had a big impact on accuracy (as well as POI).  You can try playing around with backing off the tension different amounts and see what happens (i found about half a turn loose worked very well).  I even put a dot on my shroud near the breech so that I can align it in the best spot when I take it apart.

[avator]

Yep, you are right Alan, my bad.... been a while since a had my SynRod.

[Rat Sniper (AKA: PaulT58)]

Yep, you are right Alan, my bad.... been a while since a had my SynRod.

Someone needs another cup of Joe this morning!  LOL!   

[avator]

Yep, you are right Alan, my bad.... been a while since a had my SynRod.

Someone needs another cup of Joe this morning!  LOL!   

True that.... working on my second now.

[tracker1955]

Agree on shroud being to tight against breach, back off about half a turn from bottomed out. Also, keep oring on stripper greased good so shroud can move easily during the shot cycle. Some Marauders do best when shroud has hobby foam between it and barrel band, mine however doesn't like it and shoots best when just centered in the band with equal daylight showing around it.

[superchikn]

I have been chasing accuracy issues with my 22 Liberty.  checked everything I knew to check.  Some pellets shot great some times but lately nothing would group.
After reading this thread I went out and shot a few mags and was shooting the same as last weekend.
Although the shroud slides snuggly onto the barrel blocks/ o rings and snugs up in the barrel band I had been leaving out the shroud screw at the rear barrel block.  I did not see the shroud moving but there must have been some negative effect.
I replaced the screw and at least 6 pellets are now stacking.
Hard to imagine but that little screw seems to have made a world of difference on my gun.
Thanks all.

[ShakySarge]

Agree on shroud being to tight against breach, back off about half a turn from bottomed out. Also, keep oring on stripper greased good so shroud can move easily during the shot cycle. Some Marauders do best when shroud has hobby foam between it and barrel band, mine however doesn't like it and shoots best when just centered in the band with equal daylight showing around it.

I agree with this. An over-tight shroud can really throw groups off from my experience.

Breech screws torque is another good point. An un-centered breech is no bueno and can also interfere with cocking as well. I would also check the oring that sits between the shroud spacer and the breech. If it was mounted to tightly, it can certainly affect accuracy. Certainly check all the baffles and the end cap for clipping. Also check the oring at the muzzle shroud spacer. O-rings do more than seal on the marauder, in the shroud they center the barrel.