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Author Topic: Barrel bands...  (Read 4067 times)

Offline ribbonstone

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Barrel bands...
« on: July 06, 2007, 02:36:54 PM »
..have come to the conclusion that (at least with these two rifles) it doesn't make any difference...also suspect that there are rifles out there where it will make a differnce.  So long as the breech is tightly screwed down, the barrel o-rings in good condition, and the barrels screwed down tight, these two QB's shoot as well one way as the other...if yours is wandering. might look at the screws that hold the breech/barrel on.

Using two QB78's (a .177 and a .22), testing each for a week or so, and slightly abusing the rifle looking for POI shifts have tried:
(1) no band..barrel just hanging from a well tightened breech.
(2) issue plastic band.
(3) issue plastic band with a full diameter screw (required slotting/notching the barrel).
(4) epoxying the band to the gas tube, barrel free to slide.
(5) after market metal band.
(6) TWO plastic bands (only on one QB)
(7) epoxying the TWO barrel bands to the gas tube, barrel free to slide.

IF it's made one bit of difference in accuracy, can't detect it.  Free floating did show a POI shift with barrel stressing; none of the others did (at least at this level of stressing).

I'm going to leave it with the two epoxyed bands.


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Robert

Offline shadow

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RE: Barrel bands...
« Reply #1 on: July 06, 2007, 02:42:13 PM »
Well that is nice to know and thank's for putting your shooter's through some testing for us. :) Ed
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I airgun hunt therefore I am... };)  {SHADOWS Tunes & Camo}  airguncamo@yahoo.com

Offline DanoInTx

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Re: Barrel bands...
« Reply #2 on: July 06, 2007, 04:00:31 PM »
The bands that RJMachine makes actually clamp to the gas tube and allow the barrel to slide as the gas tube expands and contracts.  IMHO that is the way it should work....not that it always does, but the method is sound at least.  Plus his bands are prettier than the issued bands:)
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Dan

Current shooters: Beeman HW97K .177 with Hawke Eclipse 4x16x50SFAO and Steve C. stock, Beeman R9 .177 with Hawke Airmax 4-12x40AO and Gene\'s Midas touch, Air Arms S200 with Bushnell Banner 6x24x40AO Rowan brass bling and Steve C. custom stock, BAM B25, BAM B40 .177 with BSA 3x12x44AO, Benjamin Marauder .22, Benjamin 397 pumper.

\"repeat this mantra:
Air gunzzzzzz, air gunzzzzzz, air gunzzzzzzz!!!  ...You will feel better\" T.E.C.2008

Offline JMG

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Re: Barrel bands...
« Reply #3 on: July 06, 2007, 04:15:06 PM »


And per a recent email from Robert himself he has an abundance of the bands for sale right now.........Check them out here.



John

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Ok I shoot....maybe not well but I do shoot hehe, B26-2.177, X3-B3-2 .177, RWS 34 .177, QB78 Deluxe .177, CR 1322 Medalist
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Offline ribbonstone

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Re: Barrel bands...
« Reply #4 on: July 06, 2007, 04:30:43 PM »
That's what is listed as #5 trial....it's going on the .177 version tomorrow.

Is a nicely made unit, certainly prettier than the double band, but I'm not done with that test rifle yet.   Keep thinking about a steel version, with the bottom soldiered to the gas tube. Not a problem to dissasseble...barrel goes through the upper section just fine, band stays attached to the gas tube (same way with the epoxied bands).
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Robert

Offline JMG

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Re: Barrel bands...
« Reply #5 on: July 06, 2007, 04:45:52 PM »


I was curious if there was an issue that got you started in testing the bands? Or is this just a fun project for peace of mind? I know that my QB78D has a metal band and I havent had any issues personally with poi shift. I have read a lot of posts about people having probs with it so I am just curious if you have had probs or?



John

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Ok I shoot....maybe not well but I do shoot hehe, B26-2.177, X3-B3-2 .177, RWS 34 .177, QB78 Deluxe .177, CR 1322 Medalist
[img=../photos/get-photo.asp?photoid=610]



Offline ribbonstone

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Re: Barrel bands...
« Reply #6 on: July 06, 2007, 05:46:18 PM »
No real stablity issues...have knocked it pretty hard when hunting and lost zero, but that only takes a few shots to get back,  Just  wanted to try more area rather than just a stiffer (metal) band.  Seems to work well enough.

Have slapped a dial indicator onto the barrel, with the base attached to the gas tube, and was kind of disheartened by how much fingers could push the barrel out of line and NOT have it quite return to zero when free floated....which got me to thinking about ways to stabilize the system.

A steel band soldered onto the gas tube would come closer to "bullet proof".
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Robert

Offline JMG

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Re: Barrel bands...
« Reply #7 on: July 06, 2007, 05:55:39 PM »


Ahh very intersting indeed... I will watch your progress and see what you come up with. Good luck and I will be waiting on the other side hehe.



John

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Ok I shoot....maybe not well but I do shoot hehe, B26-2.177, X3-B3-2 .177, RWS 34 .177, QB78 Deluxe .177, CR 1322 Medalist
[img=../photos/get-photo.asp?photoid=610]



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Re: Barrel bands...
« Reply #8 on: July 07, 2007, 01:46:51 AM »
The RJ bands where 15mm so your good to go if you have a deluxe, AR or 79.  Standard QB's have a 14mm dia, could run a shim since its ment to float and only act as a guide/stop.

Cheers
Mark
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Offline DanoInTx

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Re: Barrel bands...
« Reply #9 on: July 07, 2007, 02:36:08 AM »
Quote
blondelazer - 7/7/2007  8:46 AM

The RJ bands where 15mm so your good to go if you have a deluxe, AR or 79.  Standard QB's have a 14mm dia, could run a shim since its ment to float and only act as a guide/stop.

Cheers
Mark


Really?  The one I had wouldn't fit on my AR2078, only my standard QB78.  I emailed Robert about getting a 15mm one at the time and he said that he was only making the 14.1mm standard QB78 version.  Never know though, that all may have changed.  This was almost a year ago.

Dan
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Dan

Current shooters: Beeman HW97K .177 with Hawke Eclipse 4x16x50SFAO and Steve C. stock, Beeman R9 .177 with Hawke Airmax 4-12x40AO and Gene\'s Midas touch, Air Arms S200 with Bushnell Banner 6x24x40AO Rowan brass bling and Steve C. custom stock, BAM B25, BAM B40 .177 with BSA 3x12x44AO, Benjamin Marauder .22, Benjamin 397 pumper.

\"repeat this mantra:
Air gunzzzzzz, air gunzzzzzz, air gunzzzzzzz!!!  ...You will feel better\" T.E.C.2008

Offline ribbonstone

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Re: Barrel bands...
« Reply #10 on: July 07, 2007, 02:36:37 AM »
If you need to shim one, I a lot of time getting a plastic shim (had started with brass...decided plastic would work better)...want that barrel to be able to slide a bit (well... if anything moves, it would be the gas tube contracting).  After all that work, found that teflon plumber's tape would work just as well and is a devil of alot easier to do.  Don't think it was a 1mm difference, but there was some slack.  

(edit: spell like a hillbilly on a 3-day drunk)
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Robert

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Re: Barrel bands...
« Reply #11 on: July 08, 2007, 12:10:44 PM »
Weird when I asked if they where 14mm for my two Archer carbines this was his reply...

Hi Mark......actually they are 15mm......Yes I have
them........thanks....Robert

Robert Jones
http://www.RJMachineshop.com
- Show quoted text -

That was on 25 April 2007, perhaps he has both now?  Archer carried the metal ones in 15mm but not 14mm.

Cheers
Mark
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