Gunsmithing What info is needed to match muzzle brake with barrel?

[goodgorilla]

I have a krieger barrel ordered and I will be changing the contour so that it will support a muzzle break. Currently I have a contour #11 ordered, and will be going down. I know I would like to have a Holland radial break put on, if you want some figures I'll give you the links. Also, the caliber bullet I will be firing will be a 7mm rem mag. I also know I want a 9 twist. Can somebody help me match the contour with the muzzle break?

Krieger contours:
Contours

Krieger 7mm barrel info:
Calibers & Prices

Holland muzzle breaks with dimensions:
Holland's Gunsmithing & Shooters Supply

This is my current guess:
I should get a contour of 10, which has 9.30 diameter at the end of the barrel. So, I would like to get a muzzle brake that is tapered down to 9.30. The bullet hole size in the barrel is .277 and the exit hole of the break needs to be .02 larger than that which would be .279.

I called krieger, and they said they will fit the muzzle brake on the rifle, all I need to do is call the muzzle brake manufacturer, give them the correct end diameter + caliber, then they should have the info they need accept for extra features which I can ask about.

 

[Kebo57]

You may get lucky and find a brake that fits your barrel dimensions at the muzzle exactly....if you do you shoulda bought a lottery ticket instead! Typically you order a brake that is slightly larger than the end of the barrel and then turn the brake to match the barrel. Also re-check your math....adding 0.020" to 0.277" = 0.297" . Only 2 thou clearance on a brake is a bit close. Any competent smith than can thread and install a barrel or brake correctly can match the taper of the brake to the barrel after its installed.

 

[goodgorilla]

I have the muzzle break ordered, and is being shipped to krieger. He's how it went down for anyone who may have the same situation. I researched the muzzle break that I wanted, which ended up being a Holland partly because the diameter of my barrel at the end is going to be .93 (which Holland makes a brake that can fit that size). So I called up Holland and told them I wanted a muzzle break, but needed help selecting one. They asked me what was the diameter at the end of the barrel, I told them .93, they asked what caliber, I told them 7mm. Then they told me what model I should pick and asked if they could ship it off to krieger which I agreed. I called up Kriger to see if there was anything more required to have a muzzle break sent to them, and they told me it would be very helpful if Holland would put my krieger order number on the package, so I called up Holland and they will be doing that. I still don't understand what some of the figures mean on the Muzzle breaks, but the Holland seemed to know. Many of the issues I was worried about, krieger takes care of in their threading + muzzle install service.

 

[Straight Shooter]

None of the Holland brakes have bottom ports. Radial in this case refers to reverse angled ports.