CVA Accura MR QR breech plug project

[bestill]

Without question the asg plug is better. And as stated its what i use in every custom build.
If it will withstand hundreds of shots in a extreme smokeless build im all in.

Only reason for Bestill plug is to be a improved replacement for knight bolt guns. Which cant be converted to rear sealing.

 

[Smyrnagc]

I wanted to chime in and say this thread has provided some of the more interesting gun forum reading this year. I really appreciate the members who share their technical insight and experiences.

X2!

 

[bestill]

Jpstanley,

If you can retrofit to a rear sealing plug with degrading rifle integrity all good.

A rear sealing plug function in same way our flash hole and flame channel works.
Rear seal never sees chamber pressure. As ignition happens pressure flows back breech threads clearance which restricts flow as bullet exits muzzle the pressure flow on breech has only traveled a few threads so rear seal sees very little pressure.
A front seal plug sees peak pressure immediately.

For example a Remington700 has a bolt raceway of .710 so asg rear sealing breech is .690 to allow freely to slide thru bolt raceway and uses a .562 thread leaving a .064 sealing surface.

A knight has a .710 bolt raceway but uses a .687 breech thread leaving hardly any sealing surface.

 

[JStanley]

Thanks bestill for the feedback. I'm strongly considering this project. If it is successful, it will breath much needed new life into this guy's rifle. Here's another quick question: I've never seen or handled a rear sealing plug except here at MML. How much clearance (if any) is there between the nose of the plug and the shelf area of the barrel? A few thou or as little as possible? Thanks again!

 

[a1smokepole]

clarification :
The plug on left is arrowhead sporting goods breech plug.
I use in all custom builds.

Bestill plug is a custom fit knight bolt gun breech plug not pictured.

So which is better? The plug i pictured i thought was what you put in my Knight rebuild? I just bought an extra for back up for whatever reason.

I no when Luke tested his plug he used a test barrel and a rem 700 ml action and the barrel blow up with 300,000 psi + and then he unscrewed the plug out of the blown up barrel no damage.

 

[bestill]

Thanks bestill for the feedback. I'm strongly considering this project. If it is successful, it will breath much needed new life into this guy's rifle. Here's another quick question: I've never seen or handled a rear sealing plug except here at MML. How much clearance (if any) is there between the nose of the plug and the shelf area of the barrel? A few thou or as little as possible? Thanks again!

I drill .187 deeper than needed thread depth then tap with bottom tap.
Just don't want to go much more so cleaning jag and patch wont get stuck.