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+P chambers

FrankG

So I'm throwing this out here and I'm going to be very blunt about it.

Here is my stance on +P chamber throats. You're cutting away the height of the lands as well as making the throat longer as I understand it and from what I've seen in several barrels (one barrel the throat was another .750" longer) customers have sent back to us. So guys think they can run a heavier powder charge etc... to get more velocity and keep pressures down. Ok fine but by doing that you can expect it to have a negative impact on barrel life/accuracy.

This is another variable beyond our control. You want to put a bigger camshaft in your cars engine and a bigger carburetor I get it but then you add nitro methane in your gas tank our put nitrous on it as well to go even faster.... there is a trade off for going faster. You don't get to eat your cake and keep it to.

So I've told all my guys in the office here... I will not warranty any barrel that a customer thinks the barrel died early etc... and they are running a +P chamber set up.

Later, Frank
Bartlein Barrels
 
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Frank, I am surprised you would warranty the barrel life on any chamber.

Granted, every shooting Disciplin has expectations as to what constitutes acceptable barrel life. A PRS shooter shooting a 110 grain 6 mm bullet in front of 50 grains of what ever powder should have lower expectations as to when the barrel is gone than a shooter shooting a 6 BR with the same bullet in front of 30 grains of powder.

You manufacture barrels out of the finest steel available, machined to the highest standards. That should be where your liability ends.
 
Jackie, No we really don't warranty a barrel from a barrel life perspective. There are too many things beyond our control as you and I know.

Every once in a while a guy has a problem in regards to barrel life etc.. and sends it in. Sometimes we can put our finger on what caused the problem and sometimes not. So at times I do and will support the customer.

This +P chamber throat thing though... no way.

Thanks for the kind remarks!

Later, Frank
 
Here is some info from Starline Brass about 9MM+P.

Our 9MM+P has no difference from the standard 9mm Luger other than headstamp designation for load segregation. Due to standard case design, it will handle +P pressures with no problems. **NOT RECOMMENDED FOR USE IN S&W SHIELD PISTOLS WITH NEAR-MAX OR +P LOADS, DUE TO LACK OF CHAMBER SUPPORT IN SOME PISTOLS** WE ALSO DON'T RECOMMEND USING THIS BRASS IN S&W 929 OR 986 REVOLVERS (OR ANY OTHER REVOLVER WITH A TITANIUM CYLINDER) DUE TO POSSIBLE HARD EJECTION ISSUES.

Yup what he said.
 
BigBolt said:
Here is some info from Starline Brass about 9MM+P.

Our 9MM+P has no difference from the standard 9mm Luger other than headstamp designation for load segregation. Due to standard case design, it will handle +P pressures with no problems. **NOT RECOMMENDED FOR USE IN S&W SHIELD PISTOLS WITH NEAR-MAX OR +P LOADS, DUE TO LACK OF CHAMBER SUPPORT IN SOME PISTOLS** WE ALSO DON'T RECOMMEND USING THIS BRASS IN S&W 929 OR 986 REVOLVERS (OR ANY OTHER REVOLVER WITH A TITANIUM CYLINDER) DUE TO POSSIBLE HARD EJECTION ISSUES.

Yup what he said.
Click to expand...
Not sure if you’re tracking? +P pistol ammo is different from what some people are doing with what they are calling +P chamber reamers for the rifles. Does that make sense?
 
That is also touted by Randy Selbly to get maximum case capacity from any given cartridge. Throat the chamber to where what ever bullet you choose does not protrude into the body of the case.
Of course, he deals mostly with rifles used in hunting.
 
jackieschmidt said:
That is also touted by Randy Selbly to get maximum case capacity from any given cartridge. Throat the chamber to where what ever bullet you choose does not protrude into the body of the case.
Of course, he deals mostly with rifles used in hunting.
Click to expand...
I did that on my 6.5X47L in order to shoot the Hornady 147 ELD-M and keep the bullet out of the shoulder. Had to take it out .170". The barrel had over 1200 through it. It worked fine. With a little more powder and no pressure signs I was able to get 2864 with the 140s and 2815 with the 147. It was just a fun project. Had no idea there was a name for it.
 
Old Navy said:
I did that on my 6.5X47L in order to shoot the Hornady 147 ELD-M and keep the bullet out of the shoulder. Had to take it out .170". The barrel had over 1200 through it. It worked fine. With a little more powder and no pressure signs I was able to get 2864 with the 140s and 2815 with the 147. It was just a fun project. Had no idea there was a name for it.
Click to expand...
That sounds like a normal "long" throat.
 
From what I remember reading there was/is a .300 Ultra Mag +P chamber where half of the height of the lands is cut away in an effort to reduce pressure and increase velocity. I think this is what Frank is referring to; taking an already high intensity round and cutting out half the throat from the get go.
 
rwj said:
I had not heard of a +P rifle chamber until this post! Is it a relatively new notion?
Click to expand...
No, it isn’t new. It’s been around quite some time now and a few in this thread are obviously confused as to what it actually is.

+P in a rifle throat is not just a long throat like a traditional Weatherby throat. It’s a term and a throat type patented by Shawn Carlock of Defensive Edge. It’s also known as a bore rider throat. It’s a normal throat followed by a cylindrical section of the lands removed at about half height.
defensiveedge.net

+P Throating Applications

+P Throating Applications After fielding like a hundred questions about +P throating I decided to sit down and collect up all of our research and prior +P modified rounds. In short the +P modification is a benefit if there is sufficient capacity left in the case at the current load. For example...
defensiveedge.net defensiveedge.net

Bore Rider throat discussed here with an example reamer print:

Alpha 6ppc Brass......Maybe..

Tom Danielson 6PPC Brass1 message Rick, Thank you reaching out and it's great to hear the Dasher is working well. Is there a standard for the PPC of are the a bunch of different reamer prints? I reached out to Tom at Alpha letting them know I liked their Dasher brass and thought there would be...
forum.accurateshooter.com

Another example:

IMG_1580.jpeg
 
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Adam in WI said:
From what I remember reading there was/is a .300 Ultra Mag +P chamber where half of the height of the lands is cut away in an effort to reduce pressure and increase velocity. I think this is what Frank is referring to; taking an already high intensity round and cutting out half the throat from the get go.
Click to expand...


Basically this, it is also referred to as a stepped chamber or Bore Rider as pointed out by Wsnyder in his post
 
D Coots said:
Will do Frank.

Wasn't Murdica messing with the bore rider in a PPC?

Later
Dave
Click to expand...
I know Lou did shoot some bore rider chambers but not sure if he is using them anymore. I'd have to ask him if he is or not.

Give you a shout a little later.
 
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