Barrel porting

Birdhunter1 · Post by **Birdhunter1** » Tue May 17, 2005 1:16 am

What exactly does porting a barrel do?

What about backboring?

Post by **Greg Jennings** » Tue May 17, 2005 5:45 am

Porting:

Barrel porting, in my experience, helps with muzzle jump and, thus, helps you get on a second target more quickly. It does not, in my experience, significantly help with recoil.

Backboring:

Backboring is simply increasing the bore diameter of a shotgun. In my experience, in helps with the "snap" of recoil...spreading it out over a longer time interval.

Some claim that it helps produce more uniform patterns.

I think it got its start in back boring some European shotguns that had significantly under-sized bores. They would really rattle your teeth.

Both are more applicable to competition shotguns where people are willing to pay for every possible edge...a couple of targets out of a thousand.
Best,

portsider44 · Post by **portsider44** » Tue May 17, 2005 1:55 pm

I think Greg is right on the money. I bought a 12 ga 26" HK Silver Lion O/U last year. Which came with Fabarms Tribore system which includes the extra long forcing cones, back bore & being ported.

YOu will seee all kind of comments on porting (reduces recoil, makes it louder, reduces muzzle jump, better patterns...) I have never patterned my guy so I can't talk about that. I can let you know I had a lot better hit to miss ratio then with my Rem 12 ga 1187. Of course I think being limited to 2 shoots & having more open chokes (Impr Cyl top, Cyl bottom) vs impr cyl may have been the reason.

The guys I hunt with & myself didn't think it was any louder then the pumps & autos they were shooting. Can't say recoil was any softer then my friends nonported O/U. So unless you could prove that the patterning would be better I can't really see what value they add.

Would I buy another gun that was ported yes, would I pay to have a unported gun ported no.

Birdhunter1 · Post by **Birdhunter1** » Tue May 17, 2005 11:35 pm

Thanks guys

Post by **Ayres** » Wed May 18, 2005 12:26 am

Heck, and all this time I thought one of the main appeals of porting was to cool the barrel down faster since it's mainly on the 'sporting' guns that one would expect gets a lot of shells run though in succession (skeet, clays, etc.)

Post by **Greg Jennings** » Wed May 18, 2005 5:25 am

Ayres wrote:Heck, and all this time I thought one of the main appeals of porting was to cool the barrel down faster since it's mainly on the 'sporting' guns that one would expect gets a lot of shells run though in succession (skeet, clays, etc.)

The vents in the rib(s) are for cooling. Ports are really for muzzle jump. Most of the time back boring and lengthened forcing cones are for enrichening the gunsmith or gun company.

Best,

Mtnspaniel · Post by **Mtnspaniel** » Mon Jul 25, 2005 1:10 am

I have hunted around and with a fair number of guys with ported guns, and I also have one myself. JMO but they do reduce muzzle jump, especially with heavy loads. Muzzle blast gets directed to the sides and is significantly louder. In a duck blind ports are down right obnoxious because of this, not to mention pieces and parts of wads being spit to the sides. Most of the negative stuff you will not notice from behind the gun, but for my dogs sake, I save the ported guns for the target range and use nonported guns hunting.

Emptypair · Post by **Emptypair** » Thu Nov 30, 2006 11:31 am

That is also right on the money...muzzle blast sucks! As Greg said they are great on target guns but being right next to another hunter in a blind isn't any fun. It is pretty cool to see the flame during an opening minute volley.

ohiogsp · Post by **ohiogsp** » Thu Nov 30, 2006 4:38 pm

Yes, they are annoying. Would never have anouther one.

Wagonmaster · Post by **Wagonmaster** » Thu Nov 30, 2006 5:14 pm

In the 90's I shot a sporting clay or two. My first sporting clay 12 ga. O/U I had ported. It generated quite a bit of muzzle blast. In fact, I have seen bushes as far as 30 feet to the side of the shooter being waved around by the gas discharge.

Eventually I decided to go to 32" barrels and put together a custom gun. I bought a used Bereatta 680, the predecessor to the 682. It was a flat rib, fixed choke, trap gun. I had screw in choke tubes put in by Briley. All this means for this discussion is that these particular barrels were lighter at the business end than most barrels you will find today, which have heavier factory tubes. Thus, I was a little concerned about muzzle jump.

I also had Briley remove the forcing cones and backbore and polish the barrels. Backboring opened them up to a barrel ID of .735 rather than the normal .729 of Berettas.

Because backboring and removal of the forcing cones tends to tame recoil and muzzle jump, and because I already disliked the ports, I decided to test for muzzle jump before having porting done.

I set up a test apparatus where the gun rested free on sandbags and a pencil was attached to the barrels, which would draw a line on a piece of paper, and if I measured that line I would know how much muzzle jump I had. I figured that I could then test the gun after porting to see if it did any good.

Imagine my surprise when I fired the gun and the barrels did not move. Not an inch not a millimeter. So I fired it several times with several different loads. Same result.

Now, this is not exactly what will happen with any other shotgun. These were long barrels, remember, and I was shooting target loads, mostly 1 oz. but I tried some 1 1/8 also.

I also took a number of lessons from two great English shooting coaches, Jack Mitchell and John Woolley, and shot with some of the English shooting greats. At the time, they were the best shooters in the world, as borne out by the fact that they would walk away with the World Sporting Championship, a very very difficult event with lots of doubles, every year. I noticed that none of them shot guns with ported barrels. Most were sponsored shooters who could shoot anything they wanted, but none used ports. I talked about this with them. Here is the conclusion I came to.

Muzzle jump is not a big deal unless you are shooting heavy loads, say greater than 1 1/4 out of a 12 ga., in a gun with a light muzzle and/or short barrel. What we often view as muzzle jump is not that at all. Rather, on firing, the butt of the shotgun tends to slip down a little on the shoulder because of the recoil. A "grippy" recoil pad can help with this. But in reality, what you need to do is to remount the gun just a little bit in between shots. With some practice it becomes habit.

But porting, actually, does pretty much squat for a shotgun except make it louder to those around you and to cost you money.

littleking · Post by **littleking** » Fri Dec 01, 2006 6:55 am

ported barrels on shotguns do nothing but make them louder... not enought pressure to make any significant change in recoil

gundogguru · Post by **gundogguru** » Tue Dec 12, 2006 6:44 am

littleking wrote:ported barrels on shotguns do nothing but make them louder... not enought pressure to make any significant change in recoil

This statement is dead wrong I shoot a SBE with 3 1/2 ammo all duck season. Last year I sent my barrel off and had it ported and the forcing cones lengthened and it made a world of difference less recoil and half the muzzle jump.

Post by **pear** » Tue Dec 12, 2006 7:42 am

I'm not going to argue the porting issue, with anybody but, I'd say most all of the positive result was from the extending of the forcing cone, and very little if any from the porting. ..."pear"

Chaingang · Post by **Chaingang** » Tue Dec 12, 2006 9:13 am

I'm going to have to side with Pear on this one. I have shot competetive sporting for probably longer than I care to admit, and have over the years done all the barrel mods that are available. Lengthening the cones on a shotgun which have short cones from the factory (inch or less) will do more for reducing felt recoil than any of the others combined, especially a break open gun. From what I was told by a barrel smith lengthening cones over 3 inches is redundant, and no further gains will be produced.

gonehuntin' · Post by **gonehuntin'** » Tue Dec 12, 2006 7:10 pm

If you want to lose your hunting buddies, port your barrels. Last I talked to Briley, they felt backboring did nothing significant for a gun and talked me out of it. They were in favor of lengthened forcing cones however.