308 Win chambers. Is a match chamber really necessary?

[FloatPilot]

It has been decades since I had an action rebarreled. When ordering a barrel to be installed, there used to be match chambers and standard SAMMI chambers for the 308. Now I am seeing Alfa neck reamer size as a sort of in between.
With a good 5R barrel, is there really any reason to go with the tighter Match chamber these days?

 

[Edds]

Match chambers and 3/4 race cams are nothing without numbers.

 

[FredHammer]

I’d only punch the throat to handle the CBTO measurement that would allow the bullet to seat bearing surface at boat tail at the shoulder/neck junction.

 

[lash]

It really depends on what your intended use for the rifle is to be. Unless it’s for actual sit down match use, I’d avoid a match chambering. Turning necks and other shenanigans in order to get good feeding doesn’t do anything for me when I’m loading for hunting or action type competition.

 

[CerebralDistortion]

Match chambers and 3/4 race cams are nothing without numbers.

This.

What defines a match chamber to you (OP)?
Longer free bore? Will it exceed max mag length? Will you single load?
Tight neck? Will you forego the ability to use factory loads?


The short and long of it since you need to ask: No.

 

[Commutair]

Interesting thread. I wish we had more replies!

 

[RTH1800]

I’d only punch the throat to handle the CBTO measurement that would allow the bullet to seat bearing surface at boat tail at the shoulder/neck junction.
View attachment 8262890

With a detailed chamber drawing like this what could go wrong?

No offense intended.

 

[FredHammer]

With a detailed chamber drawing like this what could go wrong?

No offense intended.

I certainly made heavy use of comedic liberty when I presented that illustration! Although the idea is still sound.

On another note, it sure has made me wonder if a longer throated 708, increasing the case capacity in that manner, would be as beneficial as the 708AI route...

 

[B y r o n]

I certainly made heavy use of comedic liberty when I presented that illustration! Although the idea is still sound.

On another note, it sure has made me wonder if a longer throated 708, increasing the case capacity in that manner, would be as beneficial as the 708AI route...

Have you checked to see if the magazine would hold this longer round?

 

[FredHammer]

Have you checked to see if the magazine would hold this longer round?

That's a good consideration, but this would be for a no mag, single feed. The 708AI magazine fed gun COAL is already as long as I can make fit in the mag so I am stuck to 708AI route.