What's your opinion of factory PORTING?

[Mister_Mossberg]

I've been considering buying a second Mossberg, a 500. I currently own a basic 590A1, and I am thinking of a basic 500 with the thinner lighter barrel. Sometimes I see "factory ported" models for sale, and I'm not really looking for porting but it seems that every time I like something it is ported.

Are there any drawbacks to Mossberg factory porting? I did a Google search for Mossberg factory porting but the only thing I found was that most agreed it doesn't help much, if at all.

I don't care one way or another about porting, I just want to make sure that if I do buy a ported Mossberg I will not regret it. This will be for a house gun... Thanks all!

 

[oli700]

I haven't shot one with Mossberg factory porting but have some porting exp and have Vang Comp porting on my 500. I think if porting is done with a lot of small holes vs just a couple big holes the flash at night isn't an issue and there is a picture/video of Vang Comp port work that proves it actually cuts muzzle flash over a stock barrel with no porting at all, its located in the Vang Comp thread

The other thing about porting is noise. Without a doubt it is louder to the shooter, especially under a shelter or in doors. Recreational shooting , or any shooting with ear protection its a non issue but if you ever shoot it without ear protection you will notice quite a bit of difference.

other than that it definitely doesn't hurt performance in a shotgun, how much it helps muzzle rise is debatable considering a shotguns lower pressure at the muzzle

 

[John A.]

It is an interesting subject and I like the question. Something I spent a little time researching before I built my first suppressor.

Porting has been around for a long time. It started out probably during the early part of WW2 when the U.S. and Britain were doing a lot of testing with suppressor design. And several of the best designs in the world revolve around a ported barrel. The Delisle suppressed carbine, the MP5SD, the integral suppressors of various kinds, etc.

I know that your question wasn't even about that, but I like to inject a little history into the topic, and to just put it out there that placement of porting on a barrel can actually slow the bullet velocity down affecting it negatively if placed near the chamber because it vents a lot of the gas that would otherwise propel the load down the barrel, or as in the case of shotgun porting, place it near the muzzle so it does not affect velocity as much because of the short amount of dwell time after the bullet passes the ports and probably already full powder burn, but even then, there are several different types of ports, and that's where I would like to add to what Oli was saying.

There are large ports, small ports, and even ports that are drilled through the barrel at angles depending on design. Some people drill them at an angle rearward to act as a compensator, and those type are louder because some of the muzzle blast is directed back toward the shooter, but may make follow up shots just a little bit faster and may also not foul as quickly.

As for Mossberg factory porting, I believe that they're drilled straight into the barrel. Probably wouldn't do much in a HD situation either way.

Or you can port your own barrel with a good sharp bit, some oil, and a drill press. X/Y table optional.

Just wanted to throw that out there.