polygonal barrell vrs reg lothar barrel

Forums Field Target Field Target Talk polygonal barrell vrs reg lothar barrel

  • Views : 3306
  • Link

    aa_limited
    Participant
    Member

    hey guys what barrel is better  for shooting jsb 8.4 and jsb 10.34 pellets.
    ​a polygonal barrel or a regular lother barrel.

    ​I hear people saying latly that polygonal barrels only shoot jsb 13.4 accurately?
    ​any truth in this

    Link

    chasdicapua
    Participant
    Member

    My .177 polygonal barrel does shoot the 13.4’s the most accurately, but I wouldn’t say it doesn’t shoot the 8.4 and 10.34 pellets inaccurately. Just not quite as accurate as the 13.4.
    The 10.34s are pretty close. The 8.4’s are not as accurate mostly because they’re going too fast (980fps in my TM 1000). The 10.34’s are round 900fps. Much better speed for accuracy. 

    Link

    Percula
    Participant
    Member

    “aa_limited”​I hear people saying latly that polygonal barrels only shoot jsb 13.4 accurately?
    ​any truth in this

    
Yes and no. Yes there are a lot people shooting very accurately with JSB 13gr, while not having as much luck with heavier/lighter weights, but there are also people shooting lighter and heavier very accurately.

    Every rifle is different. They key is tuning your rifle to the pellet. By tuning I mean being able to adjust the FPS you are shooting each weight at. Get a chrono crank your velocity down to about 700fps and shot some groups or a series of 25m/50y bulls in calm or indoors at your desired shooting distance (or as close as you can get 25y vs 25m). If you’re not happy with the accuracy bump the velocity up by 25fps, repeat. Do this in small steps till you find the right speed. If you are well into the 900s you are likely not going to get better with faster as supersonic buffering is starting playing a part.

    I shot BR accuracy with my Thomas with polygon barrel with JSB 16gr at 880fps. I have yet to test 13gr or lighter, but I will sooner or later.

    I know you are/were looking at a RAW BM500, so call Martin or Mark and ask them what you need to do to shoot those weights accurately. 

    Link

    aa_limited
    Participant
    Member

    I really trying to decide what barrel to get. jsb 104 and 8.4 are what I want to get shooting acturate.
    ​ do the polygonal barrels cost more I wonder.

    Link

    chasdicapua
    Participant
    Member

    The polygonal barrel does not cost more.  It’s just a barrel option you have on the RAW’s .177 rifles. Not sure about if it costs more for the .22 and .25 rifles. 
    Mine is shooting the 10.4 JSB’s very well. I haven’t changed the velocity, so chances are it could shoot them better. Shooting them at around 900fps right now and the 8.4’s around 970. 

    Link

    sharroff
    Participant
    Member

    I have a 24″ poly on my new Steyr build.  At 19 ft/ls, the 13s are outshooting the 10s.  I haven’t even tried 7s or 8s yet.   I do plan on dropping the fpe on the rifle this weekend and seeing if the 10s tighten up.  If they do, I’ll fine tune for accuracy then do the same with 8s and 7s.

    Here is how they do in my gun (copied from anoher of my posts)

    For each group, of 3 targets I filled the rifle to 3k psi.  The target was 1/4″ red dots at 20 yards.  I started with the full length moderator.  Pellets are unsorted from tin and lubed.  You are looking at 10 JSB 10s on  target 22, 10 AA 10s on target 23 and 10 JSB 13s on target 25.    Scope is set up for 10.3s with the full length moderator for indoor shooting at this point, so they are dead center on bullseye.  No real surprises here, 10.3 are dead center and 13s are a bit low.So here was where I was curious.  If all these Thomas BRs have no moderator and the RAW BM 500s have no moderator, wonder what happens if I just take the full length moderator off and shoot?  Here are 30 unsorted pellets in the same order: JSB 10s on 8, AA 10s on 9, and JSB 13s on 10.Well!  Lookey there!  We have a definite POI shift about 3/8″ up and 3/8″ right on all groups.  Look how those groups all tightened up a little bit though…especially the 13s.  Looks like the pellet has less variation leaving the barrel crown ‘directly’ vs ‘whatever’ is happening inside the moderator.Now with the air stripper.  Rifle is refilled to 3k psi, and I shot  30 more pellets into the target with the pellets in the same order.JSB 10s on 3, AA 10s on 4 (I pulled one high on this target or it would have looked more like #3) and JSB 13s on 5.  Once again we have a very different POI.  This time, hitting about 3/8″ to 1/2″ low and maybe and 1/8″ right.  Look at how the things tightened up again, especially the 13s!!  I’m not kidding, that is 10 pellets though the same exact hole this time.
     

    Link

    aa_limited
    Participant
    Member

    are you saying your gun is more accurate with the moderator or with out it?

    Link

    sharroff
    Participant
    Member

    My gun is most accurate with the air stripper / flip compensator.  It is least accurate with the moderator.  The naked barrel is in the middle.

    Link

    aa_limited
    Participant
    Member

    what airstripper do you use?

    Link

    chasdicapua
    Participant
    Member

    I had the thought of trying that with my TM 1000 which has a moderator on it. I’ll definitely check it out now seeing your results. Thanks for posting those. I’d also be curious what air stripper you use and how it is attached as there are no threads on the end of the barrel. 

    Link

    sharroff
    Participant
    Member

    aa_limited,

    My poly barrel is a full 24″ so I had Allen Zasadny make me a custom unit to fit my gun.

    Chasdicapua,

    It is a 15″ piece  that slides (very snugly) over the barrel and is held in place by allen screws.  You can see one clearly on the right hand side of the lower picture and about 1″ from the end of the unit close to the black bracket on the top picture.


     

    Link

    chasdicapua
    Participant
    Member

    I did an experiment with shooting groups with and without the moderator on with the .177 polygonal barrel on my TM 1000. I shot 4, 5 shot groups at 20 yards with it on and off. The average group size with the moderator off was .063 and with it on was .077. So, I got the same results as sharroff. I imagine with 10 shot groups, the difference would have been a bit greater. So, it seems this could be a trend. Just so you guys with moderators on your .177 polygonal barrels will know. 

    Sharroff,
    How did you get the piece that’s attached to the end of the barrel that aligns and hold on the moderator off? I took off the grub screw and it wouldn’t budge. Didn’t want to crank on it too hard. Does it have lock tight on it and need to be heated?  Any info. would be helpful, thanks.

    Link

    sharroff
    Participant
    Member

    Chasdicapua,

    My .177 poly (a RAW barrel) is installed in my Steyr LG 100.  There is nothing on the barrel at all.  Both my moderator and air stripper/flip compensator slide over the barrel then lock in with allen screws.

    On my RAW .30, I can remove the endcap (green arrow).  On the base piece (red arrow), I can remove the allen screw but can not remove the piece that sits over the barrel.  I have a hunch that Martin used some sort of adhesive so that the whole moderator doesn’t slide down the barrel if that gets loose.  I’d suggest giving Martin a call and letting us know what you find.

     

    Link

    chasdicapua
    Participant
    Member

    It’s the end cap I was speaking of. Took off the grub screw, but still very tight so as not to be able to remove it.  I’ll call Martin and see what he says. Thanks for the pictures. 

    Link

    Sam63
    Participant
    Member

    “aa_limited”hey guys what barrel is better  for shooting jsb 8.4 and jsb 10.34 pellets.
    ​a polygonal barrel or a regular lother barrel.

    ​I hear people saying latly that polygonal barrels only shoot jsb 13.4 accurately?
    ​any truth in this

    BSA hammer forged barrels are notorious for shooting 10.3 and 8.4 very accurately. If your looking for a barrel the BSA is my recommendation. Both BSA barrels I had in 177 shot the 10.3 and 8.4 JSB’s extremely accurate. I have 2 polygons now and neither love the JSB 10.3 or 8.4. 

    Below are links to websites in England that sell airgun spares. Both carry barrels.

    http://www.airgunspares.com/store/product/11150/Air-Arms-S200-Barrel-.177/

    https://www.gunspares.co.uk/categories/24908/Airgun-Barrel-Blanks/

     

    Link

    aa_limited
    Participant
    Member

    I’m buying a raw so I dnt think raw will be putting one of those on.
    ​right now on my air wolf. its loves jsb 8.4s on low power 875 fps. loves them and it don’t like 10.3s

    ​where did you get your polygons barrels and what gun do you have them on.

    Link

    TonyT
    Participant
    Member

    You can purchase polygonal Lothar Walther barrels directly from the manufacturer. If I remember correctly they were $125 each and are 24 inch long and 16 mm diameter. An easy fit for the Steyr LG110.

    Link

    Sam63
    Participant
    Member

    Didnt know your were buying a RAW. Martin knows a lot more about barrels than most especially when it comes to his masterpieces. If it were me I would explain to him exactly what I was looking for then listen to his advice.

    That said when I was looking for a barrel replacement for a 177 Air Wolf I asked AZ which barrel he recommended for accuracy and power. He said buying a barrel is a lottery, “you can buy two barrels made the same time. The 1st barrel machined and the 2nd right after. One can be a laser the next a dud.” AZ then said if your looking for high fpe the polygons like heavier 13 and 16 grain 177’s pellets.

    Yesterday I was testing dozens of pellets and at 12 fpe found the Air Wolf loved the H&N 7.5 lights. Consistent dime size groups at 50 yards. Then tried medium weight pellets at 16 – 17 fpe. The H&N 9.57 hollow points shot better than the JSB 10.3 or 8.4, quarter size groups at 50 and sub dime at 45 yards. Never thought a HP could be this accurate past 25 – 30 yards. AT 33 fpe the gun loves 16.2 and at 20 – 23 fpe it likes 13.4’s.

    The 2nd polygon barrel went on a 177 Cricket rifle. The barrel was bought the same time as the barrel for the Air Wolf. The barrel has less than 150 pellets through it but I can tell accuracy is not as good. This coming Friday is suppose to be good shooting weather and will continue testing. One thing I am 95% sure the polygon is less pellet picky compared to the standard LW barrel.

    One last thing to consider the polygon is noticeably heavier than the standard LW barrel. RAW’s are heavy guns. I would ask Martin the weight difference between the two barrels before making your decision. 

    Photo of the Cricket with polygon:


    Video of Air Wolf with polygon above.

     

    Link

    aa_limited
    Participant
    Member

    why would a poly barrel be more heavy considering length and barrel profile are exactly the same?

    Link

    Sam63
    Participant
    Member

    The metal is thicker or denser? I do not know why but the polygon is noticeably heavier. The extra weight is mostly towards the front, I felt the difference in both guns. Ask martin to weigh both. My guess is the polygon will be 15 percent heavier.  

Viewing 20 posts - 1 through 20 (of 20 total)

You must be logged in to reply to this topic.