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Does porting effect shot speed or pattern?

Discussion in 'Shooting Related Threads' started by bodybuilder, Jul 25, 2010.

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  1. bodybuilder

    bodybuilder TS Member

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    I was wondering if porting effects and slows down your shot speed alittle thus effecting your pattern?
     
  2. Neil Winston

    Neil Winston Well-Known Member

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    No, but if it works, it must make the gun shoot lower, which can be a good, bad, or neutral thing.

    Neil
     
  3. hmb

    hmb Well-Known Member

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    Yes, but Neil hasn't figured out a way to measure it yet. HMB
     
  4. Big Heap

    Big Heap TS Member

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    Open the website.

    More facts, theory and conjecture than you ever wanted to know about porting.

    Somewhere in all this text you will find a reason to port your trapgun barrels.
     
  5. phirel

    phirel TS Member

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    I agree with Neil, porting must make the gun shoot lower; however, I am not convinced that it will shoot very much lower. Porting should not reduce velocity. There is not a velocity difference between a 30 and a 32 inch barrel. So if reducing the barrel length by 2 inches does not reduce velocity, a few holes in inch or so from the end of the barrel will not measurable reduce velocity.

    Pat Ireland
     
  6. chipdaddy

    chipdaddy Member

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    Do ported choke tubes have the same effect as porting the barrel??? Jerry
     
  7. Pull & Mark

    Pull & Mark Well-Known Member

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    No Porting will not slow down your load. Powder is burned long before the shot leaves the end of the barrel. Porting does nothing but make a mess in a choke tube. My 2 cents, Heres why porting is done to reduce barrel jump after the shot for a better follow up shot on 2nd target. It might help so that the shooter can see his target break better on a one shot game without lifting his head. It will not reduce recoil so that you can even tell it was done, and it will make your barrels dirty around the holes and make harder to clean. I believe it reduces barrel jump by around l/4 to l/3 percent or so depending on your loads. Its not worth having your gun done if its not done already, but if you want to do just the bottom of your O/U, its up to you. It will devalue many barrels. Nuff Said. Break-em all. Jeff
     
  8. hmb

    hmb Well-Known Member

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    If the powder is burned long before the shot leaves the end of the barrel, please explain why there is a lot of unburned powder in the barrel when you use some slow burn rate powders. HMB
     
  9. timb99

    timb99 Well-Known Member

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    <i>"I was wondering if porting effects and slows down your shot speed a little thus effecting your pattern? "</i>

    Probably, but its not measurable or noticeable.

    <i>"Do ported choke tubes have the same effect as porting the barrel???"</i>

    No. Ported barrels have the ports on top, which has the effect of reducing muzzle rise. Ported chokes are ported all around the circumference of the choke tube, so they cannot reduce muzzle rise.

    Neither is particularly effective at reducing recoil.

    As Neil has calculated in the past, using well documented formulae, it "can" reduce recoil, but only by about 2% or so of the overall recoil.
     
  10. Pull & Mark

    Pull & Mark Well-Known Member

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    The slowest burning powder for a shotgun is the 410 gauage and that does not even use a shotgun type powder. If you look at the little skeeter type subgauge tubes they run about 18 inches long or less (410 only). Most of the powder is burned by then even in the 410. The 20's and 28's are only chamber size. Powder residue is mostly what you see. So it only seems natural to assume that a 12 ga. load even with slow burning powder would be burned before 18 inches the lenth of many field grade barrels. Break-em all. Jeff
     
  11. tumbleweed

    tumbleweed Member

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    If the pitch of the stock is correct and the recoil drives the gun straight back there should not be any "muzzle rise" in the first place.

    Am I thinking this through correctly??
     
  12. phirel

    phirel TS Member

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    tumbleweed- You left out some important things. First, your eye is much higher than your shoulder so the recoil force is never straight back. Also, ribs are usually taller at the back of the barrel than the front so when sighting down the rib, the barrel is at an upward angle to the rest of your body.

    Pat Ireland
     
  13. semperfi909

    semperfi909 Well-Known Member

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    There is no documented scientific evidence that porting does anything for a shotgun besides blow gas sideways. Everything you can read or hear about porting is nothing more than opinion. The fad of ports is past its peak. Save your money and get your stock fitted properly.

    Charlie
     
  14. Neil Winston

    Neil Winston Well-Known Member

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    Charlie, Newton's Laws, well covered in the "holes drilled" thread, explain why porting "works." You have to remember, things don't have to be documented to be true.

    Neil
     
  15. bodybuilder

    bodybuilder TS Member

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    The reason I ask is I have 2 870 TC's made 6 months apart 1 is ported the other is not, They should be almost the same gun but I can't shoot the ported one as well as the other one so I was just wondering if the porting had an effect on the patteren or shot speed?
     
  16. semperfi909

    semperfi909 Well-Known Member

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    I am well aware of the physics. That does not mean that the ports actually DO anything perceptible. Shotguns at the muzzle are not pushing anything like enough pressure like a rifle does. Anyone can play the numbers game for fun and profit. I want to see some empirical test evidence that the effect is measurable in the real world. And include that dumbass bigbore crap too while you're at it.

    Actually I don't really care. I cannot feel the effect of ports and they look really stupid besides. And, yes I have a couple ported/bored guns and thankfully I did not do that to them.

    Charlie
     
  17. bodybuilder

    bodybuilder TS Member

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    Yes Neil please explain this as only you can!
     
  18. phirel

    phirel TS Member

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    Hot air blowing out of a hole pushes jet airplanes forward. Hot air blowing out of holes in the top of the barrel pushes the barrel down.

    Pat Ireland
     
  19. trapshooterjoe7

    trapshooterjoe7 Member

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    There is a lot of hot air here!!!!
     
  20. hmb

    hmb Well-Known Member

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    Yes there is. Depending on the load you are using 8,000 to 10,000 PSI. HMB
     
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