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SBE2 Porting


tucker301

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tucker301-- I had mine ported and like the result. You have to be careful on how many vents are put in your barrel as it could effect the functioning of your Benelli. I had a gunsmith who has extensive knowledge about porting of all guns do mine. All barrels don't take the same number of vents, different length barrels take a different amount. Tucker301 e-mail me direct if you like and we'll discuss it.--GB

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1oz. 12ga. loads are available at most sporting goods stores that sell guns. Cabela's, Gander Mt., Dick's, and many others. Many sportsman use them to shoot sporting clays, skeet, trap,and lots of other shotgun games. Remington, Federal, Estate, Fiocci, Winchester andmost ammo companies make them. Hope this info sheds some light on the subject. -- GB

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1oz loads are all I use for Sporting Clays(SC). With a typical course being 100 rounds and a Tourmanment being 250 rounds , plus all the rounds burnt up in practice. Its nothing to go thru 400 rounds a week just in practice. Thus.. I want all the recoil reduction I can get. In some of my guns, I will even go as low as 7/8oz.

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That's a good quesiton turkey......I read somewhere that the only way to prevent cycling is to put the butt pad against a brick wall to stop all movement of the gun during firing. If that's the case....it only seems reasonable that the more you reduce recoil....then the more you increase the chance of a mis-cycle. If we do away with ALL recoil, then we also do away with the guns ability to cycle due to a lack of action movement. If the spring cannot depress, then the head cannot unlock.

 

Anything to add???? What do you all think???? Is it working for others???? Have you noticed an increase in jams, etc. with porting????

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My M1 90 is ported and I love it, I have never had a cycling problem either in the field on of the sporting clay range. But my question is if I port my SBE II wil that screw up the cryo barrel due to the heat from porting? But then again the barrell will get hot from heavy use too. How much heat would porting cause? How many vents should I get in mine if I have the 28" barrell?

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For the inertia system to work, the bolt has to try and stay in the same place while the rest of the gun moves rearward under recoil. Anything that reduces recoil, such as a lighter load, could reduce it to a point where the gun will not cycle.

 

There are some people that are of the opinion that porting does not significantly reduce recoil, and if that is the case, it would not affect cycling, but it also wouldn't reduce recoil. I would think that the effect of porting could be easily determined experimentally, but that is a different subject. It will increase noise.

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The inertia system works on the principle of the duration of the pressure for the first 22" of the barrel length. The porting doesn't cause more noise , it changes the directionof the noise and helps eliminate barrel jump.

 

Rancid, I e-mailed you via Private Message. But in case you wondered how many ports to put in your 28" barrel, I have * in my 28" and ^ ports in my 26".

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Benelli ports the Super Sport and Sport II, so I can assume that some Benellis can be ported in some manner.

 

I hunt with a guy who shoots a Sport II. I can assure you that that porting causes a great deal of noise for the person standing next to the gun!

 

I have heard about porting Benelli issues, but have never heard or read a verified complaint about cycling problems due to porting.

 

From the above replies, it sounds like it can be done without problem.

 

mudhen - CA

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I own a SBE II,due to a shoulder surgery leaveing me with 2 steel pins in my shoulder the recoil was making it difficult to enjoy my gun. i tried recoil reducers and limb saver recoil pad they helped,but not enough. I sent my barrel to

"Ballistic Specialties" in Batesville, Ar.

www.angleport.com is their website

These guys are great to deal with and they know what they are doing.

I had my forcing cone lengthened and had my barrel angle ported. Now my gun is a pleasure to shoot, its not any louder with the angle ports and it cycles light loads & magnum loads with no problem and kicks less than my 20 gauge.

Last weekend duck hunting at Stuttgart shot 3 boxes 3" nitro mags & 1 box of 3 1/2 mags without a sore shoulder!!!

Their Website will answer most of your questions

and it has prices too.

 

Hope this helps someone

T.

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Actually, the inertia system has nothing to do with pressure; gas operated guns like the 11-87 operate on pressure (But that is not strictly true because it is the expanding gas pushing the shot charge out of the barrel that moves the gun in the opposite direction that is required by the inertia system.) If it operated on pressure like a Remington 11-87, putting the butt of the gun up against a wall would not stop cycling, as Benelli says it does (and now I am getting ready to venture way out on a limb where I have no business). At some point, reducing recoil enough will cause cycling problems regardless of how you do it (the brick wall is the ultimate in recoil reduction).

 

It all has to do with Newton's First and Third laws. The First is the law of inertia. An object at rest tends to stay at rest and an object in motion tends to stay in motion, thus, the inertia system. The bolt is at rest; you fire the gun; the gun moves reward; the bolt tries to stay at rest and locks tighter into the barrel as it moves forward relative to the barrel because it is staying in place; at some point the spring overcomes it and throws the bolt open, ejecting the shell and cocking the hammer.

 

Newton's Third Law is that for every action (firing a shotgun shell), there is an equal and opposite reaction (recoil). Notice that it says equal. You can't make the recoil less. You can redirect it or stretch it out over more time so that there is less perceived recoil.

 

I am NOT an expert in porting or recoil reduction. However, increased noise is a known problem with porting. Some is worse than others because the sound is directed more towards the shooter to a lesser or greater extent depending on how it is done (it is a real problem for those beside you in the duck blind).

 

I have been to Ballistic Specialties' web site, and they look like a good outfit (and they are close to home). I was doing some research on recoil reduction to see what I can have done to a 12 gauge semiauto for my daughter (she only weighs 105 lb). In general what I found is that lengthening of the forcing cone reduces felt recoil (no one seems to dispute that), but opinions differed on how much porting helps.

 

As far as the Super Sport goes, remember that Benelli can adjust the springs in a production gun that they port if the porting reduces recoil enough that it is necessary to get good cycling.

 

[ 12-30-2004, 07:35 PM: Message edited by: doublebarrel ]

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Well I have had guns ported for many years and have numerous conversations with a fellow who used to run Magna- Port and it does have to do with pressure, not gas. But you can believe what ever you want. I currently have 2 Benelli's , both ported, with recoil reducers, and they both shoot 1oz. loads fine. The key is to get the cycle timing right and have the gun tuned to the ammo you are going to shoot. Porting does not reduce recoil , it helps keep the barrel down and directs the noise in a differant direction other than out in front. The most important thing is gun fit. Pitch , LOP, Drop at the heel and Drop at the comp.--GB

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Well, it really doesn't have to do with what I want to believe, it is just a complicated subject, and it is just physics and I can't change the physics (and boy are we way off subject-by the way, I can't have an opinion on the original question because I don't have a ported gun to tell you whether I like it or not-I have considered it on some of my big rifles).

 

I have seriously considered porting a 12 gauge for my daughter (if I did/do, I would let Ballistic Specialties or Magnaport do it-I trust both of them). Before I let someone cut on an expensive gun barrel, I really wanted to find out more about it. Unfortunately, I have been able to find almost no subjective information on what the effects are. Here is what I have found so far:

 

- It appears to reduce muzzle flip in big rifles and handguns by redirecting part of the gas, but in a lower pressure shotgun, it may not be noticeable (and yes, I said pressure-more about that at the bottom).

-In most cases (maybe not all), it appears to increase noise. The only real number I have seen quoted is by 8 decibels (about 60%), but that would vary greatly with different guns. I was at a local gunsmith recently, and there was a guy in there with his 300 win mag complaining about how loud it was with his muzzle brake installed (almost unshootable). Noise is a big part of felt recoil.

-In all cases, folks that sell porting services say it really works-a lot of others seem unsure or say that it doesn't.

-Gun fit is very important in felt recoil (unfortunately most people ignore it).

 

I wish I knew, because if it would reduce recoil and not increase noise, I would have it done for my daughter. All of this is easily measurable, and I would really like to run some experiments where I could measure true recoil, but then I would need to be able to afford both a ported and an unported barrel for the same gun and some other equipment (I can't believe a gun magazine has not done this-maybe I just haven't found it).

 

Pressure. I think this is how it works. You have primary and secondary recoil. Primary recoil pushes back on the gun while the bullet (shot charge) is pushed out of the barrel. Higher pressure in the barrel will accelerate the bullet faster and push the gun back faster, increasing felt recoil. Secondary recoil would be when the bullet leaves the barrel, and you are suddenly holding on to a rocket as the gas leaves the end of the barrel. As the rocket (the gun you are holding) pushes the gas out (action), the reaction is that the rocket (the gun) moves forward (into your shoulder). The actual thrust (recoil force) you get depends on the mass of the gas being expelled (bigger powder charge=more gas mass) and how fast the gas escapes. The force that expels the gas is the pressure in the barrel. The higher the pressure, the faster the gas escapes and the higher the recoil, but it also depends on the mass of the gas pushed out.

 

You would think that redirecting part of the thrust up would keep the barrel down and reduce reward thrust.

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  • 2 weeks later...
Originally posted by Golden Bear:

Well I have had guns ported for many years and have numerous conversations with a fellow who used to run Magna- Port and it does have to do with pressure, not gas. But you can believe what ever you want. I currently have 2 Benelli's , both ported, with recoil reducers, and they both shoot 1oz. loads fine. The key is to get the cycle timing right and have the gun tuned to the ammo you are going to shoot. Porting does not reduce recoil , it helps keep the barrel down and directs the noise in a differant direction other than out in front. The most important thing is gun fit. Pitch , LOP, Drop at the heel and Drop at the comp.--GB

This is a little off the subject but were you able to shoot 1oz. loads prior to making any modifications? The reason I ask is that I purchased an SBE1 (not 2) last year and it has never reliably shot even 1 1/8oz loads, I have to shoot 1 1/4oz in order for it to reliably cycle every time. The person at the gun shop I purchased it from told me that it would take about 100 rounds before the gun shot "optimally" (whatever that means). I have far exceeded 100 rounds and still it requires 1 1/4oz to cycle properly. Does this seem correct to you? Thanks, Dan.
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DD--Before I had my 2 SBE ll's worked on they wouldn't cycle with 1-1/8oz. or any other loads. But since they function every time, even with 1oz. It doesn't surprise me. Many guns, not just your Benelli need fine tuning, new or used. If you like the gun spend a couple extra $$ and have it modified or tuned for you. Hope this helps.---GB

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