Old Pyrodex...

[Jcalder]

I'm not at all familiar with what a vent liner is even, but if it can be made I can surely make it. Would be nice to find a blueprint for them.

if I had one I would take care of you, but it may be worth having someone send you one


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[451LRML]

10-32 flat head socket head cap screw slightly under 1/2" long. 0.030" Hole drilled thru.
Lehigh are domed heads and Savage are flat heads.

 

[MUP]

So the threaded section just slips into the 5/32 hole that has been countersunk ? Looks like the BP should be tapped to accept the 10-32 flathead screw.

 

[451LRML]

So the threaded section just slips into the 5/32 hole that has been countersunk ? Looks like the BP should be tapped to accept the 10-32 flathead screw.

Machine (drill/tap) the muzzle end of your BP to accept the 10-32 Flat head screw, yes you'll need a to match the angle (I can't recall if I used a 100 or 82 degree countersink?) the OD of the Flat head is 3/8".

 

[GMB54]

The link i posted has a complete walk through with pics

Then the 5/32" drill was replaced by a # 4 1/2 eighty two degree center drill; the drill was lowered until it contacted the plug, and the depth gauge on the drill press set to 3/8".

Several pics of the Lehigh vents here and they sell them too http://www.badgerridgeind.com/store/p11/LehighVentLiner

 

[MUP]

So the vent liners are just flat head, or button head screws, with a .030" hole drilled thru them. Ok , got that. I'm trying to understand why they are just seated in the 5/32" hole, that has been c'sunk, instead of having the 5/32" hole be a 10-32 tapped hole so they can be screwed into place. I guess my concern is that the liners will be able to just fall out? Thanks for your patience, as I find this very interesting and plan to modify my own BP once I fully understand the process.

 

[GMB54]

They are screwed in place. The new 5/32 flash channel is tapped to 10-32

The center drill then was used to drill a 3/8" diameter hole 3/8" deep in the end of the breech plug.

Next

the center drill removed, and a 10-32 tap was chucked
The vent to be installed has about 6 thread.
The chuck was marked with the blue line so rotations could be counted whilst threading the plug. Eight rotations were made to insure the vent would fully seat.

 

[MUP]

Ahhhhhh, ok, I understand now. Thanks again for the help GMB! Much appreciated! The entire process should be much easier in the lathe.

 

[GMB54]

MUCH easier on a lathe!!!!!

If your Kodiak gets excess blowby you can use either an o-ring that needs replacing after around 20 shots OR you can buy "shims" from Mcmasters for the primer pocket. Use smaller OD one first to measure for proper amount of primer crush. Around .003 crush is good and safe. Then use shims that are tight in the primer pocket once you know how many you need.

This is the oring you need for primer pockets if the Kodiak primers come out dirty. https://www.mcmaster.com/#9262k611/=19ev9kx

 

[GMB54]

Forgot one thing....

Try Nobel primers in the CVA plugs. They are larger OD and fit CVA plugs quite well. They work with BH209 also and are often cheaper than USA brands.

 

[Smo]

I've heard it makes pretty good fertilizer.

LOL. It has also made a few sewer pipes.

 

[MUP]

Heck, now that I have an understanding of what's needed, from end to end, I may just make a custom BP that fits my Kodiak, boring the primer pocket to the proper depth and diameter to prevent blow-by to start with.

 

[GMB54]

Heck, now that I have an understanding of what's needed, from end to end, I may just make a custom BP that fits my Kodiak, boring the primer pocket to the proper depth and diameter to prevent blow-by to start with.

Bingo, that is the correct solution. The others are a band-aide. I actually had Ron make me a old style CVA plug from a grade 8 bolt. I have a 17-4 SS plug made for my Knight 45 that is custom fit and uses a tungsten carbide bushing instead of a vent liner. Works KILLER!!!

Smokelessmz and Hankins custom rifles both sell the bushing and lock ring if you want to go that route. The bushing is pricey though. Roughly $30 a pop but they last 1000s of shots with Blackhorn or other subs.

 

[MUP]

Fortunately I work where there is no shortage of drop SS slugs. 17-4, 303,304,416 among others. What grade would be best suitable for this application?

 

[GMB54]

17-4 SS

That is what Lehigh used for his custom plugs and what Bestill uses. Cheaper ones use 416 and then heat treat since its a easier to machine IIRC.

 

[MUP]

Ok, thanks again for all the help GMB!

 

[GMB54]

Here is my Lehigh vent plug and Bestill bushing plug side by side. Both 17-4 SS. The Bestill plug has some primer fouling from testing.

 

[MUP]

So, as I've not even looked at my BP yet after seeing these measurements, I'm thinking the 10-32 tapped hole is thru to the primer pocket hole, thus opening up the centerline of the BP to the 10-32 tap size from primer pocket to flash channel, correct? This would make cleaning MUCH easier for the BP, being able to remove the liner during the cleaning process.

 

[GMB54]

Correct

The flash channel ends up being 5/32. When the vent is removed for cleaning, you just use a 5/32 bit to clean the plug. Use a pin vice to hold the bit or use a hex head bit in a nut driver handle.

 

[MUP]

Several positives to having a BP altered like this for sure.