Cobra valve question

[YEMX]

Mods, please move if this isn't the right gate.

Got a question for those of you who have, and preferably have tinkered with a Cobra valve from WAR:

My exhaust port dia. measures .20"...  Is that normal across the board for Cobra valves?  Or is the exhaust port drilled for specific applications? 

Would it be possible, modifying nothing else, to open up the exhaust port to say...  .243" or .250"?

Basically, what I'm getting at is:  is a .20" exhaust port large enough, if a full bore TP is used, to get say... 120 fpe from a 40+ grain projectile?

Yes, this is for my 6mm...   

EDIT

Additional Question:  Would it be advisable to regulate a WAR Cobra valve, or can these valves be run w/o a reg? I think I read somewhere (or perhaps a PM?  I can't remember) that Cobra valves preferred to be regulated? 

[Motorhead]

Lets clarify ...

COBRA as in a WAR valve ? .... Or a Valve that is using a COBRA chamber ?

[YEMX]

Lets clarify ...

COBRA as in a WAR valve ? .... Or a Valve that is using a COBRA chamber ?

Yessir, Cobra (or COBRA?) as in a WAR valve.  Sorry- I'll clarify the OP... 

[Jacob_M]

My understanding was that the war cobra valve does very well when regulated.

I think that the War cobra at 3000psi might require too much hammer because of how fast the valve will be shutting at that high of pressure .

Dwell would be very short.

I think.

Lol

[Motorhead]

WAR valves I have worked with ( Pre cobra ) had replaceable inner seats having different size throats.  In those guns generally 22 and under we liked to use the .250" throat seat with a max of .200" transfer path.
Above 22 cal and when after BIG power the next seat set had a .280" throat and was good for up to .250" transfer path.

So being your doing a 6MM ( .243" ) given the choice would use FULL BORE porting and ideally the .280" throat seat.  If you have the .250" seat at .200" transfer it will work, but likely be a bit more difficult to extract the power your wanting.  Which is likely going to be above 2500 psi any ways.

Generally or actually  the "Cobra" works best at a consistent pressure ( regulated )

JMO tho ...

[YEMX]

Thanks to y'all...

Scott, I'll send you a pic of the valve sometime today, let me know if one you've worked with/on before...  and you're thoughts...