Thread size question

[no worries]

What's the correct threading size for a Tikka T3 7mm magnum with a muzzle diameter of .628 ?

Stock barrel, non stainless if that matters. Just want to have it threaded for a brake.

Thanks Jim

[Tropicalmulch]

Find the appropriate brake then cut the same the ads on the barrel as the brake has

[no worries]

Thanks tropical.

What I was trying to ask is if that barrel can be threaded 5/8 inch or needs to go 9/16. Will there be enough remaining wall thickness with a 9/16 thread on a .284 bore?

 

A 9/16 thread would equal this if I'm doing the right math. .5625-.284 = .2785 divided by 2 = .13925 remaining barrel wall This seems pretty thin, but I don't know what is acceptable.

 

If I could go with 5/8 thread .625 - .284 = .341 divided by 2 = .1705

[metau]

All suppressors I've seen for 7mm have been threaded 5/8x24, so I would say that is what any brakes you find would be threaded for as well.

[Tropicalmulch]

So yes your barrel can be threaded to a 5/8-24 . And kind of what I'm getting at is if a brake manufacturer makes a brake for a .284 bullet diameter,the internal thread That is machined into that brake should be safe to put on any rife shooting a .284 diameter bullet.

So if you find a brake that's designed for a .284 diameter bullet and the internal thread is 5/8-24 that will work but the outside diameter of the brake will be larger then your barrel and will need to be blended in order to look correct. If a manufacturer makes the same brake with a 9/16-20 thread (for example) then the outside diameter of that brake may be closer or the same diameter of your barrel. (Providing a different look) I don't know if a brake designed for a .284 that has a 9/16 thread exists or not. But I would think you be ok to even go down to a 1/2-32 thread in a .750 diameter brake

[300RUM]

The Brake needs a shoulder at the end of the thread seat against. With a 0.628 muzzle if you use a 5/8 or 0.625 thread there will not be much of a shoulder at the end of the thread.

[Tropicalmulch]

300rum good point!

[Freakycamo]

I think that my tikka 300WM was threaded 1/2-28. it is one of the standard threads for muzzle breaks.

[no worries]

Thanks guys.

Seems like there needs to be a compromise that allows for a shoulder and still maintains as much barrel wall as possible.

A 300WM with a 1/2-28 thread doesn't leave very much metal. Makes me feel better about turning down this one.

[300RUM]

I've done a 30 cal Barrel with a 9/16 thread. The catch is there's just not a lot of break choices in a 9/16 thread.

[lancetkenyon]

My 7RM with APA Micro Bastard brake in 1/2-24 is turned to blend with the #3B Bartlein.

 

 

Eric @ AxisWorks has his own line that is similar. Again, turned down to blend with a #3B Bartlein.

 

[no worries]

Thanks for the input everyone. Looks like 1/2 x 28 is the best choice.

Lance, those are sweet looking rifles.

[jeffro]

GAP uses 1/2x32 a lot. VIAS MICRO

 

I have a one 1/2x32.

[lancetkenyon]

I am not a fan of radial brakes. They work GREAT. But they blow dirt, sand, rocks up into your face and all over your rifle when shooting prone or sitting. I hate that.