Cothran Valve durability

[Matt50971]

Hi everyone,

I want to put a 15.7 pound hammer spring in my marauder that has a cothran valve in it. would the 15.7 pound hammer spring damage the valve in any way? I can't find a solid answer.

Thanks,

Matt

 

[BigTinBoat]

Hi everyone,

I want to put a 15.7 pound hammer spring in my marauder that has a cothran valve in it. would the 15.7 pound hammer spring damage the valve in any way? I can't find a solid answer.

Thanks,

Matt

Here where you will likely get the best answer

[email protected]

edit - here is another email on his site

[email protected]

 

[Matt50971]

Hi everyone,

I want to put a 15.7 pound hammer spring in my marauder that has a cothran valve in it. would the 15.7 pound hammer spring damage the valve in any way? I can't find a solid answer.

Thanks,

Matt

Here where you will likely get the best answer

[email protected]

edit - here is another email on his site

[email protected]

Thank you very much!

 

[oneshot61]

I have a Cothran .308, and a Cothran valve for my armada . They both open with minimal spring. Any reason your contemplating a 15 lb spring??

 

[YamahaR1]

I have a cothran valve in my flex .30 cal and it makes 100fpe. While tuneing the rifle I've noticed after increasing my hammer preload past 1/3rd of max yielded no more power. Seems to me it needs very minimal pressure to open valve to be effective. Do you plan to run a higher pressure in your gun?

 

[ackuric]

I am also curious why you want to run 15 lb spring on a Cothran? In its intended form it requires very little spring to operate, what do you intend to do with it? 



-Matt

 

[Bullfrog]

Out of my long .300 Flex (24” barrel) I make 120fpe at a 2400psi pressure with a light hammer and mininal preload. I haven’t pushed the upper limit of the power potential. It doesn’t take much effort to make big power on a Cothran valve. 

 

[Matt50971]

I am also curious why you want to run 15 lb spring on a Cothran? In its intended form it requires very little spring to operate, what do you intend to do with it? 



-Matt

I have a 15 pound hammer spring from when i had a hill valve and it yielded more power. so i was wondering if it would do the same for the cothran valve.

 

[ackuric]

Likely not. If you want more power either get a pro to port the rifle from valve to barrel as much as possible, or you can up the pressure within the manufacturers / designs specs, increase barrel length / larger caliber or try a heavier projectile.

 

[Matt50971]

Likely not. If you want more power either get a pro to port the rifle from valve to barrel as much as possible, or you can up the pressure within the manufacturers / designs specs, increase barrel length / larger caliber or try a heavier projectile.

I have a custom .357 upper from Jefferson State Air Rilfes coming in.

 

[ackuric]

.357 upper will suffocate without proper valve work.....the cothran valve is ported 1/4" which is .25/.357 = 70 % bore porting...you should send your valve + bolt probe to JSAR and request 85%-90% bore porting equal to the .357, and plan on running a regulator around 2200 psi or so...but thats just my opinion.

 

[Matt50971]

.357 upper will suffocate without proper valve work.....the cothran valve is ported 1/4" which is .25/.357 = 70 % bore porting...you should send your valve + bolt probe to JSAR and request 85%-90% bore porting equal to the .357, and plan on running a regulator around 2200 psi or so...but thats just my opinion.

When I first talked to the lead machinist he pointed that out and it all taken care of. I've been talking to them since November about this project. I should have it soon.

 

[ackuric]

Okay you should be fine then