1. Attention: We have put together a thread with tips and a tutorial video to help with using the new software. Please take a moment to check out the thread here: Trapshooters.com Tutorial & Help Video.
    Dismiss Notice

Does porting reduce the velocity of the shot?

Discussion in 'Shooting Related Threads' started by Crickets, Jul 5, 2011.

Thread Status:
Not open for further replies.
  1. Crickets

    Crickets Member

    Joined:
    Jan 17, 2011
    Messages:
    189
    I know there are as many opinions on porting as there are guns out there. I really have no opinion either way, however I am considering on purchasing a single barrel trap gun for my wife, and this gun seems to have "more" holes than I normally see - 38 on either side of the barrel. Do you loose velocity of your shot with a ported barrel? If we are shooting light loads 1150 fps to begin with and you have porting 4-5" from the muzzle, are you not loosing a bunch of pressure pushing that wad and shot through a full choke?
     
  2. Unknown1

    Unknown1 Well-Known Member

    Joined:
    Nov 5, 2009
    Messages:
    3,396
    No!

    MK
     
  3. Lou Tenant

    Lou Tenant Active Member

    Joined:
    Oct 18, 2010
    Messages:
    430
    Several manufacturers sell barrels with ports mine included, and I do not notice any difference. 76 ports seem extreme. I would investigate further on who performed the service, and why.

    I would hate to clean that many ports. Personally, I wish mine weren't ported because of the mess during the cleaning process.
     
  4. timb99

    timb99 Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    7,328
    Location:
    Shawnee, Kansas, USA
    <i>Does porting reduce the velocity of the shot?</i>

    Yes, absolutely.

    <i>Will you notice?</i>

    Most probably not.
     
  5. Barrelbulge(Fl)

    Barrelbulge(Fl) Banned User Banned TS Supporters

    Joined:
    Aug 27, 2007
    Messages:
    11,666
    Location:
    West Central Florida
    Lou, how do you clean your ports? Bulge.
     
  6. stokinpls

    stokinpls Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    6,482
    These work pretty well.

    Just add a little elbow grease.
     
  7. slayer

    slayer Well-Known Member

    Joined:
    Nov 16, 2006
    Messages:
    2,928
    Location:
    beautiful northern michigan
    I Dont know why anyone would want to port a single barrel. It does not reduce felt recoil and barrel jump is not a factor because there is no second shot. i guess it's just to "pretty up" a gun? Bill in MI
     
  8. mx2k33

    mx2k33 Well-Known Member

    Joined:
    Nov 21, 2007
    Messages:
    1,435
    Porting does decrease velocity, by up to 160 fps depending on barrel length.

    Porting does not reduce recoil.

    Porting can accelerate rust if not cared for properly. Many barrels are chrome lined to reduce corrosion. Porting exposes the raw metal on a previously easy to maintain surface. Be sure to check the ports carefully on a used gun for rust or pitting. It will likely decrease the value of a gun just like any rusted or pitted bore.

    So porting generally accomplishes little. It costs extra to remove material from your otherwise perfect barrel, decreases velocity of your loads, accelerates rust, and devalues your gun. On the plus side, it makes more noise and might make you feel better regarding muzzle rise.
     
  9. Hoosier Daddy

    Hoosier Daddy TS Member

    Joined:
    Jul 16, 2007
    Messages:
    967
    It seems there is a difference of opinion on the matter. I personally don't think there would be enough difference in fps to worry about. My ported guns seem to break targets just as far away and just as hard as my unported guns. Some of my guns are factory ported and some have been Angle Ported and Pro-ported. I haven't noticed any tendencies toward rusting from having this done but then I keep my guns reasonably clean and oiled. Just my opinion and that doesn't mean that someone else hasn't had a different experience.
     
  10. Pull & Mark

    Pull & Mark Well-Known Member

    Joined:
    Mar 9, 2006
    Messages:
    5,404
    No Porting does not decrease the speed of a shotshell at all. The powder is completely burned long before the wad gets to the last 4 inches of the barrel. Your porting holes seem to be on the extreme side but as long as you have 18 inches of barrel no problem.
    If you don't believe me, try shooting some of the chamber type subgauge inserts. The 20 ga. and the 28 ga. are all 1200 fps loads. Now I've shot these out of a 12 ga. gun. I could not tell the decrease of speed by shooting them. No I did not crono them. The gas in these little babies can bypass the wad as soon as the wad leaves the hull, because of the extra large diameter barrels right after the forcing cone area and the whole way down the barrel as well. So don't worryaboutit. Just shoot. Break-em all. Jeff
     
  11. 1oldtimer

    1oldtimer TS Member

    Joined:
    May 16, 2010
    Messages:
    2,003
    The shot is practically out of the barrel by the time the gas reaches the ports. I don't beleive that mili second has time to change the velocity. Has it been proven to slow it down? Clyde
     
  12. mx2k33

    mx2k33 Well-Known Member

    Joined:
    Nov 21, 2007
    Messages:
    1,435
    4 boxes of factory shells and a day at the range with a chrono, pattern board, and a laptop, shooting 2 sets of 32" o/u barrels, ported and non-ported, from the same gun showed that on that day, in that gun, with those shells, porting undoubtedly slowed the charge significantly or in other words, turned a 3 dram shell into just below a 2 3/4 dram shell. More importantly though, the ported barrels shot exactly where they're supposed to and will definitely break more targets than I can.
     
  13. Brian in Oregon

    Brian in Oregon Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    25,238
    Location:
    Deplorable Bitter Clinger in Liberal La La Land
    Porting will decrease the velocity, but, there are other factors that come into play.

    Porting decreases the velocity the most on a short barrel. This is because the gas pressure is higher and it bleeds off.

    The longer the barrel, the more the gas pressure drops. So on longer barrels the difference in velocity will be less.

    If the barrel is long enough the difference in velocity may drop to the point where it is masked by the typical difference in shell velocity (standard deviation). The drop in velocity is still there, but it simply is not measurable.

    If a barrel is so long that the wad and shot column were to decelerate in the bore from friction*, there'd be no difference in velocity. I don't know how long a 12ga barrel would have to be for this to happen, but at such a length the ports would be useless. And that's the point. As long as there is enough gas pressure for the ports to be useful, there's enough gas pressure to push on the wad base.

    * This is a known factor for .22 rimfire barrels with very slow target or subsonic loads. It's provable that a .22 CB Short or Long will decelerate over 100 fps in a 28" barrel due to friction overcoming decreasing gas pressure.
     
  14. Steve W

    Steve W Well-Known Member

    Joined:
    Jan 29, 1998
    Messages:
    5,101
    Location:
    Los Angeles
    Brian made a valid statement.

    I personally don't like extra holes on my barrels, not to mention pay to have it done. But I wouldn't reject a barrel solely because it's ported. I have barrels that are ported by the previous owners, I shot them just fine, never had issues in cleaning and rust. But if I have a choice, I'd take non-ported ones.

    Many factory barrels came ported, Perazzi included. As long as there are trapshooters, we'll see ported barrels. :)
     
Thread Status:
Not open for further replies.
Search tags for this page

does a ported barrel reduce velocity

,

ported barrel decrease velocity