Calguns.net  

Home My iTrader Join the NRA Donate to CGSSA Sponsors CGN Google Search
CA Semiauto Ban(AW)ID Flowchart CA Handgun Ban ID Flowchart CA Shotgun Ban ID Flowchart
Go Back   Calguns.net > FIREARMS DISCUSSIONS > California handguns
Register FAQ Members List Calendar Mark Forums Read

California handguns Discuss your favorite California handgun technical and related questions here.

Reply
 
Thread Tools Display Modes
  #1  
Old 11-17-2019, 1:11 PM
ClickCL ClickCL is offline
Junior Member
 
Join Date: Nov 2015
Posts: 58
iTrader: 1 / 100%
Default Ported Revolvers, Higher Velocity?

So, logically, it's hard to explain; but I keep seeing instances where ported revolvers are showing higher velocities compared to their non-ported counterparts.

Has anyone else noticed this?

I understand due to barrel and cylinder fitment, there will be some variation between revolver velocities, but it does seem like there is a consistent trend.

Perhaps porting reduces the pressure needed to push the air out in front of the bullet? It's a stretch, but all I can think of.

Here are some examples:

Bullet by the inch - Notice the velocities of the 4" non-ported mt gun and the 3" ported Mt gun. Even with one inch less, the ported version produces similar and sometimes better velocites compared to the 4" non-ported. (bottom of page) http://www.ballisticsbytheinch.com/44mag.html

Gun-Test.com review - The taurus tracker which has a slightly shorter barrel and porting, matched and occasionally bested the M69 with a non-ported .25" longer barrel. (image either on the right or bottom of page shows velocities) https://www.gun-tests.com/issues/26_...l#.XdGzNkZKhO9

Forum post - Post comparing a 2" ported vs non-ported revolver. The ported had slightly higher velocities on average. https://www.thehighroad.org/index.ph...barrel.352178/

Jerry Miculek comparing 329pd's - Comparing his ported 329 to a stock 329. His ported 329 had higher velocites. (1:50-2:50) https://www.youtube.com/watch?v=v5alzzxnUKs

The argument that all of the ported examples above had tighter fitment between the cylinder and barrel either due to being shot more or luck of the draw from the factory, becomes less likely with more examples. However, this sample size is small, so it doesn't prove anything. I didn't seek the above examples out, just something I noticed today while reading. There may be many examples showing the opposite, I just haven't seen them yet.

What do you guys think?

Last edited by ClickCL; 11-17-2019 at 2:38 PM..
Reply With Quote
  #2  
Old 11-17-2019, 4:47 PM
Old4eyes's Avatar
Old4eyes Old4eyes is offline
Senior Member
 
Join Date: Feb 2010
Location: Nevada
Posts: 1,475
iTrader: 0 / 0%
Default

I have to say that logic compels one to think you are going to lose pressure by the porting and the velocity will be less.

I have one ported revolver (a Taurus, yes we all get to make mistakes) and with the night flash and the gunk kicking up from the port, using this in a self defense situation is not ideal. You might get the muzzle back onto target but the flash in a low light situation may make it difficult to see the target and if you don't have eye protection on, the gunk flying out of the ports may be a problem. But it's one man's opinion - a man who bought a Taurus.
__________________
Send Lawyers, Guns and Money - On second thought, hold the Lawyers.
Reply With Quote
  #3  
Old 11-17-2019, 5:28 PM
ar15barrels's Avatar
ar15barrels ar15barrels is online now
I need a LIFE!!
 
Join Date: Jan 2006
Location: Van Nuys
Posts: 46,923
iTrader: 102 / 100%
Default

Quote:
Originally Posted by ClickCL View Post
So, logically, it's hard to explain; but I keep seeing instances where ported revolvers are showing higher velocities compared to their non-ported counterparts.

Has anyone else noticed this?

I understand due to barrel and cylinder fitment, there will be some variation between revolver velocities, but it does seem like there is a consistent trend.

Perhaps porting reduces the pressure needed to push the air out in front of the bullet? It's a stretch, but all I can think of.

Here are some examples:

Bullet by the inch - Notice the velocities of the 4" non-ported mt gun and the 3" ported Mt gun. Even with one inch less, the ported version produces similar and sometimes better velocites compared to the 4" non-ported. (bottom of page) http://www.ballisticsbytheinch.com/44mag.html

Gun-Test.com review - The taurus tracker which has a slightly shorter barrel and porting, matched and occasionally bested the M69 with a non-ported .25" longer barrel. (image either on the right or bottom of page shows velocities) https://www.gun-tests.com/issues/26_...l#.XdGzNkZKhO9

Forum post - Post comparing a 2" ported vs non-ported revolver. The ported had slightly higher velocities on average. https://www.thehighroad.org/index.ph...barrel.352178/

Jerry Miculek comparing 329pd's - Comparing his ported 329 to a stock 329. His ported 329 had higher velocites. (1:50-2:50) https://www.youtube.com/watch?v=v5alzzxnUKs

The argument that all of the ported examples above had tighter fitment between the cylinder and barrel either due to being shot more or luck of the draw from the factory, becomes less likely with more examples. However, this sample size is small, so it doesn't prove anything. I didn't seek the above examples out, just something I noticed today while reading. There may be many examples showing the opposite, I just haven't seen them yet.

What do you guys think?
ALL of your examples rely on comparing two DIFFERENT barrels.
The way to actually test your theory is to test an unported barrel and then port it and test it again in the same conditions.
Simply changing the temperature will make one barrel faster than another and we don't know how well controlled ANY of the tests you are citing were done.
__________________
Randall Rausch

AR work: www.ar15barrels.com
Bolt actions: www.700barrels.com
Foreign Semi Autos: www.akbarrels.com
Barrel, sight and trigger work on most pistols and shotguns.
Most work performed while-you-wait, evening and saturday appointments available.
Reply With Quote
  #4  
Old 11-17-2019, 6:00 PM
hermosabeach's Avatar
hermosabeach hermosabeach is offline
I need a LIFE!!
 
Join Date: Feb 2009
Posts: 13,208
iTrader: 7 / 100%
Default

I need to ask... is the ported segment counted to barrel length?

Some guns have a port that is a brake- it’s not threaded so it does not count as barrel length


If they machines holes in the barrel, the results would surprise me.


If it’s like a S&W, where it adds length to the gun but not the barrel, so it still holds pressure behind the round- it makes more sense.



If they are chopping a barrel down, my guess is they would not machine new ports after each 1” chop
__________________




“Science is like an inoculation against charlatans who would have you believe whatever it is they tell you.”
— Neil deGrasse Tyson
Reply With Quote
  #5  
Old 11-17-2019, 6:04 PM
hermosabeach's Avatar
hermosabeach hermosabeach is offline
I need a LIFE!!
 
Join Date: Feb 2009
Posts: 13,208
iTrader: 7 / 100%
Default



__________________




“Science is like an inoculation against charlatans who would have you believe whatever it is they tell you.”
— Neil deGrasse Tyson
Reply With Quote
  #6  
Old 11-17-2019, 6:05 PM
hermosabeach's Avatar
hermosabeach hermosabeach is offline
I need a LIFE!!
 
Join Date: Feb 2009
Posts: 13,208
iTrader: 7 / 100%
Default



Different brakes and how they are measured or not as barrel length should make a difference on velocity.


__________________




“Science is like an inoculation against charlatans who would have you believe whatever it is they tell you.”
— Neil deGrasse Tyson
Reply With Quote
  #7  
Old 11-17-2019, 6:22 PM
ClickCL ClickCL is offline
Junior Member
 
Join Date: Nov 2015
Posts: 58
iTrader: 1 / 100%
Default

Quote:
Originally Posted by ar15barrels View Post
ALL of your examples rely on comparing two DIFFERENT barrels.
The way to actually test your theory is to test an unported barrel and then port it and test it again in the same conditions.
Simply changing the temperature will make one barrel faster than another and we don't know how well controlled ANY of the tests you are citing were done.
Absolutely true. Like I said, this proves nothing. Just something I noticed. And none of the examples above are scientific.
Reply With Quote
  #8  
Old 11-17-2019, 9:11 PM
k1dude's Avatar
k1dude k1dude is offline
Calguns Addict
 
Join Date: May 2009
Location: la Republika Popular de Kalifornistan
Posts: 8,867
iTrader: 7 / 100%
Default

Quote:
Originally Posted by ar15barrels View Post
ALL of your examples rely on comparing two DIFFERENT barrels.
The way to actually test your theory is to test an unported barrel and then port it and test it again in the same conditions.
Simply changing the temperature will make one barrel faster than another and we don't know how well controlled ANY of the tests you are citing were done.
As an interesting experiment, the next time someone asks you to port a barrel, ask them if it's OK to chrono the before and after with the same ammo, elevation, temp, and humidity. Ideally indoors.
__________________
“Show me a young conservative and I'll show you a man without a heart. Show me an old liberal and I'll show you a man without a brain.” - Sir Winston Churchill

“I would remind you that extremism in the defense of liberty is no vice! And let me remind you also that moderation in the pursuit of justice is no virtue!” - Senator Barry Goldwater
Reply With Quote
  #9  
Old 11-17-2019, 10:48 PM
BigFatGuy's Avatar
BigFatGuy BigFatGuy is offline
Veteran Member
 
Join Date: Oct 2010
Location: Compton, CA
Posts: 3,083
iTrader: 5 / 100%
Default

Quote:
Originally Posted by k1dude View Post
As an interesting experiment, the next time someone asks you to port a barrel, ask them if it's OK to chrono the before and after with the same ammo, elevation, temp, and humidity. Ideally indoors.
I'm sure you'd do better by asking if you could HIRE him to do these things. He does this for a living, after all.

also, AR15 is very good, but he doesn't control the weather.
Reply With Quote
  #10  
Old 11-18-2019, 3:44 AM
FalconLair's Avatar
FalconLair FalconLair is offline
Veteran Member
 
Join Date: Apr 2012
Location: Summerlin, NV.
Posts: 3,099
iTrader: 0 / 0%
Default Ported Revolvers, Higher Velocity?

good question

i purchased a Performance Center S&W Model 19 a couple of weeks ago and it has a ported barrel

unfortunately i haven't been able to try it out yet, during some dry firing i noticed the double action pull was stressing so i disassembled it and found the double action sear spring had popped out of place compromising the whole DA pull - i don't think it was put in correctly because it shouldn't pop out in that manner

S&W is sending me a new one since it got all bent up

funny how ONE little spring can shut the whole revolver down from me getting to play with it
__________________
Quote:
Originally Posted by Barang View Post

I! hate! you! FalconLair.
Quote:
Originally Posted by Greta View Post

HOW DARE YOU!!
Reply With Quote
  #11  
Old 11-18-2019, 10:44 AM
Carcassonne's Avatar
Carcassonne Carcassonne is offline
Veteran Member
 
Join Date: Jul 2012
Location: Northern California SF Bay Area East Bay
Posts: 4,643
iTrader: 34 / 100%
Default

The velocity from a ported barrel should be a little less than from a non-ported barrel of the same length.



.
__________________
Be sure to ask your doctor if depression, rectal bleeding, and suicide are right for you.

In the United States a person's expertise on a subject is inversely proportional to their knowledge of the subject: The less they know about something, the more they become an expert on it.

I am being held hostage in a giant insane asylum called Earth.
Reply With Quote
  #12  
Old 11-18-2019, 10:53 AM
JTROKS's Avatar
JTROKS JTROKS is offline
I need a LIFE!!
 
Join Date: Nov 2007
Location: NorCal - Bay Area
Posts: 11,566
iTrader: 130 / 100%
Default

Some barrels are faster. I’ve shot same handloads over a chrono from a 6” Ruger 6” Colt, and 6” S&W. Results sometimes almost 100 FPS difference.
__________________
The wise man said just find your place
In the eye of the storm
Seek the roses along the way
Just beware of the thorns...
K. Meine
Reply With Quote
  #13  
Old 11-18-2019, 12:16 PM
ClickCL ClickCL is offline
Junior Member
 
Join Date: Nov 2015
Posts: 58
iTrader: 1 / 100%
Default

Quote:
Originally Posted by JTROKS View Post
Some barrels are faster. I’ve shot same handloads over a chrono from a 6” Ruger 6” Colt, and 6” S&W. Results sometimes almost 100 FPS difference.
While I am aware of this and completely agree that is normal, of the four instances where I have found comparisons that were done by the same person/ammo, all four ported barrels are shooting faster for their barrel length.

Statistically if porting had zero/no effect I would expect a 50/50 split (sample size, once again, is too small to really draw any conclusions). But common logic dictates that porting would be worse than zero/no effect, it should have a negative effect on velocity and sway the results in favor of non-ported barrels. But it didn't... Just interesting =)

I'm with all of you, I would love some more controlled comparisons but I just wanted to see if anyone else has noticed this from their own revolvers or tests.
Reply With Quote
  #14  
Old 11-19-2019, 10:27 PM
ar15barrels's Avatar
ar15barrels ar15barrels is online now
I need a LIFE!!
 
Join Date: Jan 2006
Location: Van Nuys
Posts: 46,923
iTrader: 102 / 100%
Default

Quote:
Originally Posted by k1dude View Post
As an interesting experiment, the next time someone asks you to port a barrel, ask them if it's OK to chrono the before and after with the same ammo, elevation, temp, and humidity. Ideally indoors.
I can't shoot out of my shop yet so it's not really possible.
Maybe once I move to Carson City, I could do such testing as there is BLM land around 500yds away from my property.
This would allow me to go setup a chrono and test fire, run back to my shop and do the porting and then run back to test fire again before the weather changes enough to matter.
__________________
Randall Rausch

AR work: www.ar15barrels.com
Bolt actions: www.700barrels.com
Foreign Semi Autos: www.akbarrels.com
Barrel, sight and trigger work on most pistols and shotguns.
Most work performed while-you-wait, evening and saturday appointments available.
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



All times are GMT -8. The time now is 1:00 AM.




Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Proudly hosted by GeoVario the Premier 2A host.
Calguns.net, the 'Calguns' name and all associated variants and logos are ® Trademark and © Copyright 2002-2018, Calguns.net an Incorporated Company All Rights Reserved.
Calguns.net and The Calguns Foundation have no affiliation and are in no way related to each other.
All opinions, statements and remarks made by Calguns.net on this web site and elsewhere are solely attributable to Calguns.net.