Head Space

[smokey92]

Merry Christmas All.

How would I go about measuring head space in my CVA Kodiak Pro?

[MountainDevil54]

i dont think you can adjust it but cva recommends snugging the plug up tight and back back off a 1/4 turn on the breech plug.

[sabotloader]

Originally Posted by MountainDevil54

i dont think you can adjust it but cva recommends snugging the plug up tight and back back off a 1/4 turn on the breech plug.

That's crazy you are going to loose the gas seal at the face of the plug....

[MountainDevil54]

with that style of plug, there really isnt a seal in the first place. A lot of blow back into the threads.

[sabotloader]

Originally Posted by MountainDevil54

with that style of plug, there really isnt a seal in the first place. A lot of blow back into the threads.

Is it not the regular CVA Hex Head plug? If so there is a seal at the fron of the BP against the flange in the barrel... The turn it up snug that you talked about...

Shoot! even my fire bolt had a face gas seal. and that was years ago.

[MountainDevil54]

yeah its the hex head BP but it doesnt seal up blow by from getting into the theads. Its not like a QRBP which is basically 100% free of blow by into the threads.

[sabotloader]

Originally Posted by MountainDevil54

yeah its the hex head BP but it doesnt seal up blow by from getting into the theads. Its not like a QRBP which is basically 100% free of blow by into the threads.

Granted it is not the QR plug but the Hex head plug will seal if installed correctly with grease but for sure with tape.

Backing a plug off also offers a possibility of a plug moving back and fourth a slitght amount in the threads each time you shoot. All plugs should be ran up snug in the bore. Just like you adjusting head space by turning out the firing pin bushing this is going to lead to mechanical stress on the threads at some point could cause metall fatigue... Nut and bolts with threads are ment to be snug or tight to prevent problems.

Most ML's are designed to stop gas cutting and gas seal at the nose of the breech plug. Backing the plug out will accelerate gas cuting on the BP and the face of the flange of the barrel.

[smokey92]

Nowhere in my manual does it suggest backing off the BP. Only not to "over tighten". Sabotloader is correct in grease or tape on the face reducing blow back. That's been my experience so far. I've used bore butter on the threads, from time to time, when just hunting (1 or 2 shots) and have had no issues removing the plug. Extended range firing I use anit-sieze on the threads.

"i dont think you can adjust it"

So if modifying or having a "custom" plug made, it should be the same length as OEM?

[ronlaughlin]

Originally Posted by smokey92

Merry Christmas All.

How would I go about measuring head space in my CVA Kodiak Pro?

If you have a caliper, it seems you could measure the length of the primers; install them in the plug closing the action, and remeasure. Shim the primer bit by bit until it measures shorter. This will tell you when a slight compression of the primer occurs. This then should be your working 'head space'. Measure the OAL of the shimmed primer in the breech plug and the breech plug.

Have your custom made breech plug with primer of choice in place be made to this OAL or a couple thousandths longer.

[Chasam60]

Do you have a headspace problem?I bought a .25 ACP breechplug from Cecil that was not bored deep enough.I used a counter bore to carefully cut the bore deeper until my breech closed properly with just a couple thousands squeeze.

Charlie