Choke Tube Porting

[mnbeardbuster]

If a choke tube maker changes the locations of only the porting on a choke tube model, would that have any affect on the pattern?

[SR1]

NO porting has no effect on a pattern. The holes just vent gasses.

[Skeeterbait]

The porting on a choke tube occurs too late before the wad exits the bore to have much if any effect on gas release and recoil.  The porting on choke tubes act as wad brakes.  The edges of the port bite and grab the wad to slow it down helping the shot exit the wad earlier and not be disturbed in flight by the wad tumbling.  Ports in barrels occur further back and only on top to help offset muzzle rise.  Ports in choke tubes occur all the way around evenly to grab the wad evenly.  So yes, change in port location or design can change pattern.

[SR1]

I have tried lots of ported and non-ported chokes and have never seen a difference in the patterns. Must be it only affects hunting loads and not trap or skeet loads. Some chokes are designed to strip the wad but not all of them. Just because it has ports doesn't mean its there to strip the wad. If that was the case porting on the barrel would start that process way before the wad got to the choke.

[mnbeardbuster]

Let's say for discussion sake we took a PG and widen the space between the ports.  Say some close to the barrel and the last set where they are currently.  Or if there were more ports.  Do you think that could change how the wad is stripped and thus change the pattern?

The reason I ask, is I have a Truglo choke that was made by Mark Bansner for Truglo.  I found another one made by him but it has more ports.  I like the pattern I am currently getting and I want to try and duplicate that on another gun.

[turkey_slayer]

The porting on a choke tube occurs too late before the wad exits the bore to have much if any effect on gas release and recoil.  The porting on choke tubes act as wad brakes.  The edges of the port bite and grab the wad to slow it down helping the shot exit the wad earlier and not be disturbed in flight by the wad tumbling.  Ports in barrels occur further back and only on top to help offset muzzle rise.  Ports in choke tubes occur all the way around evenly to grab the wad evenly.  So yes, change in port location or design can change pattern.

I argued with guys on another forum about this.  They said the ports were to reduce recoil.  You have done got the full recoil from the gases by the time it gets to the choke.  But I agree, port locations can change the pattern.

[turkey_slayer]

Let's say for discussion sake we took a PG and widen the space between the ports.  Say some close to the barrel and the last set where they are currently.  Or if there were more ports.  Do you think that could change how the wad is stripped and thus change the pattern?

The reason I ask, is I have a Truglo choke that was made by Mark Bansner for Truglo.  I found another one made by him but it has more ports.  I like the pattern I am currently getting and I want to try and duplicate that on another gun.

The way I see it, the more ports the more to grab the wad.  But is there a point where after so many you are just destroying the integrity of the choke without gaining anything?

[ILIKEHEVI-13]

Choke tube geometry along with porting styles all can change the effects of patterns from a particular load.  I agree that porting doesn't do much to tame recoil from what I have seen shooting turkey loads out of a shotgun barrel.  I use to believe that porting had little effect on patterns from a particular load, and that was true on a lot of the certain styles of the ports I tested vs other ported chokes and non-ported chokes, but I have now come to the conclusion that a lot of it depends on the particular design of the ports from the chokes you test.  But the actual choke tube geometry on how the inside is made from conical to parallel is probably the most important aspects to effecting patterns along with the actual smoothness of the machining finish on the inside of the choke.