Urban owners-Do you have any barrel band POI shift issues?

[Tommyzgunz]

Hey guys , while I've been researching the Urban , both through the forum and on line, I came across a few people complaining about POI shift and the barrel bands. Is it a free floating barrel?

I have only seen a few people mention this on line and no one has really mentioned it in my previous posts on this forum while asking about the Urban and how you guys like it. For the most part a lot of people love it. But I'm curious about this. Have you guys had issues with the band and POI shift from shooting session to the next time you pull it out , and if you remove the band, wouldn't you now have even more possibility of POI if the barrel is nudged in and out of a case or during transport?.

Like I said I only heard a few people mention the poi problem and I'm hoping there has only been thaat few occurances. Nothing would be  more frustrating than the gun to be off zero often.

[Luis Leon]

All I did was loosen the screw on my barrel band, no issues with accuracy at all. Others have cut it off.

[Ribbonstone]

  Never hurts  to try things you can quickly put back to orginal....so I hve tried  the band tight and the band loose. In my case, couldn't tell any real difference in accuracy, but without the band tight, it did tend to wander it'sPOI at ther least excuse.

[Tommyzgunz]

All I did was loosen the screw on my barrel band, no issues with accuracy at all. Others have cut it off.

I would have to see. Preferably not cut it off if not necessary.

[Tommyzgunz]

  Never hurts  to try things you can quickly put back to orginal....so I hve tried  the band tight and the band loose. In my case, couldn't tell any real difference in accuracy, but without the band tight, it did tend to wander it'sPOI at ther least excuse.

Thanks. I guess it's one of those where checking out the accuracy tight might be easiest.

[SpeedyBB]

When I had one it definitely shifted poi with a bump of the barrel, and bad too. For me, loosening that screw did not help if memory serves. If I had kept it I would have cut it off and figured out how to make my own floating barrel band like the marauder has.

[MaineJim1821]

I have had mine for 2 years ,it's bone stock and i haven't had to readjust my scope one click since i put it on.
Gun has just over 3.5k pellets through it and it's a tack driver.

[Pb_Volare]

When I had one it definitely shifted poi with a bump of the barrel, and bad too. For me, loosening that screw did not help if memory serves. If I had kept it I would have cut it off and figured out how to make my own floating barrel band like the marauder has.

No worries.
Remove barrel band screw,
Remove fill port dust cover,
Slide barrel band towards pickle,
   This should roll o-ring out of engagement
   from between barrel and band
      May take more than one attempt.
Roll o-ring out of the way
Slide barrel band back into position
Replace fill port dust cover
Either replace barrel band screw or use for trigger mod, it's just about the right length.

[Tommyzgunz]

I have had mine for 2 years ,it's bone stock and i haven't had to readjust my scope one click since i put it on.
Gun has just over 3.5k pellets through it and it's a tack driver.

excellent thanks.

[moorepower]

The BSA guns don't use on, so I cut mine off. Its a 16mm barrel. It's not moving.

[moorepower]

The BSA guns don't use on, so I cut mine off. Its a 16mm barrel. It's not moving.

When I took it off, it bent the barrel down about .020 to slide it back on. Not a good thing. This was after removing the screw, so running it loose would not help.

[Ribbonstone]

Did try mine...4 times ..will soon be 5...from when I put it away sighted in. Pellets from the same tin I used when I put it away for awhile.  IF there was any shofting of shoter range groups (25 yards) I couldn't detect it.

1.Tired it right out the safe with the same pellets it had been using (from the same tin).
2.Tried it after ridfing back and forth to work on the floor boards of my Jeep.
3. Tried it with the barrel band loose and pushed over the brass front end cap (which is smaller and lets the bottom just kind of "rattle".(There is no just taking it off unless you debarrel the rifle and get it off to the breech end).
4. Tried with with the loose barrel band and the same ride to and from work.

GOOD NEWS: Grouping stayed the same.

BAD NEWS: it shifted POA/POI only with #4.  Even then, it only shifted 1/5" at 25 yards (to about 1 o'clock).But in MOA terms, that's close to 1MOA shift (actually,more like 8/10ths).  Not a lot of shift,but it only showed up without the band and lightly rought handling.

Things suspected:

5. If you loosen the barrel band (or remove it) and the gap between the barrel and air tube changes,then there is some kind of tension interaction. Might be the fit of the barrel to the breech,might be the fit of the breech to the air tube,might be a bent barrel.

6. There is an o-ring in that upper barrelband section. It's not easy to get that o-ring back into it's race if it pops out...but if you don't,expect some changes (as you are then inducing a new tension from the non-centered o-ring).

7.The bottom of ther band rests over the internal part of the front fill cap....that area sees no pressure.  The upper section is o-ringed,so the band irs realitively free to slide front to back on the barrel.  I don't see any tube pressure induced changes.


So on a guess...if a loose band vs. tight band (or no band) makes a big difference in where or how it groups, there is something wrong with #5 or #6.

---------------
Now I'm moving onto the harder 5th test session...getting that o-ring in the barrel band back in it's race, the band back in place and tightened (considering the material,do not go for "gorrilla tight"),and yet another shooting session before the light fades.

Hoping it goes back to test #1....but with so much pharting around, likely I'll have to start over.

[Insanity]

When I put a bipod on mine I was clumsy with it and it flopped over a few times. Poi changed from poa but grouping didnt I was about 2 inches right after the flops.

[Ribbonstone]

Got to thinking...how bad could a barrel band be?

Turns out, the barrel band on a nicely accuirate .177Beeman Chief is the worst-winner.


Shoots well with the band tight and the barrel centered.

DSCN1832 by Robert Dean, on Flickr


Lossening the band and an appication of one hand-thumb pressure. Really light pressure had it fex back to near the starting point.  Stronger pressure(whifh isn't all that strong) made it stickin gthe "off"alignment.,

DSCN1830 by Robert Dean, on Flickr

Didn't really see the need to see how far off it was shooting...the visual evidence was that it would be a "ship loaD. 


Point being, in this case, that it's the fault of the barrel to breech fit than the barrel band.

[Tommyzgunz]

Got to thinking...how bad could a barrel band be?

Turns out, the barrel band on a nicely accuirate .177Beeman Chief is the worst-winner.


Shoots well with the band tight and the barrel centered.

DSCN1832 by Robert Dean, on Flickr


Lossening the band and an appication of one hand-thumb pressure. Really light pressure had it fex back to near the starting point.  Stronger pressure(whifh isn't all that strong) made it stickin gthe "off"alignment.,

DSCN1830 by Robert Dean, on Flickr

Didn't really see the need to see how far off it was shooting...the visual evidence was that it would be a "ship loaD. 


Point being, in this case, that it's the fault of the barrel to breech fit than the barrel band.

Interesting thank you.

[moorepower]

Did try mine...4 times ..will soon be 5...from when I put it away sighted in. Pellets from the same tin I used when I put it away for awhile.  IF there was any shofting of shoter range groups (25 yards) I couldn't detect it.

1.Tired it right out the safe with the same pellets it had been using (from the same tin).
2.Tried it after ridfing back and forth to work on the floor boards of my Jeep.
3. Tried it with the barrel band loose and pushed over the brass front end cap (which is smaller and lets the bottom just kind of "rattle".(There is no just taking it off unless you debarrel the rifle and get it off to the breech end).
4. Tried with with the loose barrel band and the same ride to and from work.

GOOD NEWS: Grouping stayed the same.

BAD NEWS: it shifted POA/POI only with #4.  Even then, it only shifted 1/5" at 25 yards (to about 1 o'clock).But in MOA terms, that's close to 1MOA shift (actually,more like 8/10ths).  Not a lot of shift,but it only showed up without the band and lightly rought handling.

Things suspected:

5. If you loosen the barrel band (or remove it) and the gap between the barrel and air tube changes,then there is some kind of tension interaction. Might be the fit of the barrel to the breech,might be the fit of the breech to the air tube,might be a bent barrel.

6. There is an o-ring in that upper barrelband section. It's not easy to get that o-ring back into it's race if it pops out...but if you don't,expect some changes (as you are then inducing a new tension from the non-centered o-ring).

7.The bottom of ther band rests over the internal part of the front fill cap....that area sees no pressure.  The upper section is o-ringed,so the band irs realitively free to slide front to back on the barrel.  I don't see any tube pressure induced changes.


So on a guess...if a loose band vs. tight band (or no band) makes a big difference in where or how it groups, there is something wrong with #5 or #6.

---------------
Now I'm moving onto the harder 5th test session...getting that o-ring in the barrel band back in it's race, the band back in place and tightened (considering the material,do not go for "gorrilla tight"),and yet another shooting session before the light fades.

Hoping it goes back to test #1....but with so much pharting around, likely I'll have to start over.

My thinking goes back to #7. If the whole tube flexes at all with changes in pressure, the poi will change. Many Urbans have been reported in the past shifting poi as the pressure dropped. The Urban has a much better receiver to mount than the QB or Disco that begs for the barrel to be moving around with only 2 screws holding on the breach. I actually run 2 bands on my Discumus. With out the band my poi has never shifted. 1000-3300 psi it has never moved. I lean the barrel against the side of my safe, so it sets with extended periods leaning on the barrel. I am not anti barrel band, but as good as the BSA twins are without one, I decided after my findings of my band, i did not want one on the Urban. Somewhere on the interweb I watched someone fill a air tube with the breach secured to a bench and he put a dial indicator on the fill end and filled it up. It moved enough to move the poi a decent amount. Not every tube is going to have as many stresses in it but it is possible. I shot mine Wednesday and it still shot in the same hole, so it worked for me