Vent liner question

[silentstalker]

I shoot a CVA Accura MR and use BH 209. I also use a CVA BH 209 breech plug.

Will I need a vent liner at some point? How or where is the best place to get set up with the ability to use a vent liner?

 

[MrTom]

Factory and factory replacement plugs will all eventually "shoot out", the flame hole [the tiny hole in the powder end of the plug] will enlarge enough that accuracy fails and blowback becomes a real issue. Many of these factory plugs can be drilled out and tapped to allow a vent liner to be installed. CVA plugs are fairly simple to do. Vent liners are made of much harder steel and will give quite a bit more longevity and cost about $5.00 apiece as opposed to the retail cost of a replacement plug.

 

[HC]

sskfirearms.lehighdefense.com , has the replaceable ventliners breech plug for the cva (2010 and newer) $26.

 

[rangerod]

Send a pm to ronlaughlin who is a member of this forum. He can do the work that you need.

 

[silentstalker]

Thanks all! I will check with Ron!

 

[GM54-120]

The BH209 plugs are not ideal for the conversion. You want to convert a standard CVA QRBP not the BH209 version. Using the BH209 plug you will end up with an even shorter flash channel. The standard plug can be modified to give a similar channel volume.

 

[silentstalker]

That is good info. I have the original breech plug too so it sounds like I could modify that one.

 

[GM54-120]

That is good info. I have the original breech plug too so it sounds like I could modify that one.

The original plug modded the way Ron does them IMO is the best plug for the CVA other than maybe a full LRMP plug conversion with a tungsten bushing and that is WAY more expensive. The bushing alone is about $30 but will last a super long time too.

 

[ronlaughlin]

I shoot a CVA Accura MR and use BH 209. I also use a CVA BH 209 breech plug.

Will I need a vent liner at some point? How or where is the best place to get set up with the ability to use a vent liner?

No, one does not need a vent liner.

You already have all you need.

A factory plug could be converted to a Blackhorn plug by utilizing a vent liner. If you have me do the work, it will cost you about $35. This conversion won't shoot any better than the Blackhorn plug you already have.

When the flash hole in your Blackhorn plug wears out, which is around 0.037", you will need to replace the plug. If the plug had a vent liner, one just replaces the vent liner.



An interesting conversion would be to install a tungsten carbide bushing into the factory plug. This flash hole would never wear out. Seems like this would be worth around $85, perhaps $100..

 

[silentstalker]

Thank you Ron!

So last question for this topic (I think) how do I measure the flash hole? Is there a cleaning tip or rod I can find locally that is .037"

I will have to think about that tungsten carbide bushing as a lifetime fix...

 

[ronlaughlin]

Use a #63 drill as your gage.

 

[RoJo]

Factory and factory replacement plugs will all eventually "shoot out", the flame hole [the tiny hole in the powder end of the plug] will enlarge enough that accuracy fails and blowback becomes a real issue. Many of these factory plugs can be drilled out and tapped to allow a vent liner to be installed. CVA plugs are fairly simple to do. Vent liners are made of much harder steel and will give quite a bit more longevity and cost about $5.00 apiece as opposed to the retail cost of a replacement plug.

If I recall correctly, you shoot the Accura V2. I also shoot the Accura V2. I am assuming you had your QRBP drilled for using vent liners. I’m curious, is there an estimate for about how many shots you get from a vent liner if one consistently shoots 100 gr BH by volume? Where does one buy them and are the vent liners from Lehigh considered sufficient for the converted BP? Thank you in advance for your reply.

 

[BadgerRidge]

There are a few sources of vent liners... I believe I sell the best ones: 17-4 stainless, heat treated, and made in the USA by Lehigh (aka Millennium Manufacturing). How many shots depends on a lot of factors... first what do you deem too big of a flash hole (typically they start around .030 and when they grow to .036 you are either just starting to see your groups open up, or about to). But there are other opinions on flash hole sizes (Where to start and when to replace). And how big of a group change is acceptable.

You should get 100-150 shots on one of our stainless vent liners... the other options aren't always heat treated or aren't made out of steel that will take as many shots. I have one customer that claims to have over 300 shots on one of the newer stainless vent liners and still can't get our .036 pin gage through it. But it really depends on so much one cannot tell you how many shots... how are you cleaning them? What brand of primer are you using? what powder? How much powder? How high of pressure are you subjecting them too? Are you letting them cool between shots? etc.

To me, the fact that many manufacturers would rather sell you a new breech plug than to use vent liners (or another replicable flash hole system) is a big tell.

Any yes, the Lehigh vent liners work great in converted breech plugs (assuming the work is done correctly and their is enough steel in the breech plug for it to be converted). They are essentially interchangeable with the standard Savage ventliner and are the most common readily available type.


Hope to help.

Tom

 

[MrTom]

I have one customer that claims to have over 300 shots on one of the newer stainless vent liners and still can't get our .036 pin gage through it.

That may well be me. My Accura V2 and Optima V2 pistol and my .45 cal Kodiak all use converted plugs and the Badger Ridge vent liners. The liners and plugs are cleaned after each shooting session with the exceptions being during the 9 day deer season when the plugs and liners are cleaned at the end of it. I just ran down and looked in my shooting log and to date the Accura has 288 shots thru the liner with a 77 weighed grain 209 charge behind a 250 grain Barnes XPB, the Optima has 311 shots thru it's liner with a 63 weighed grain 209 charge behind a 225 grain Barnes XPB and the Kodiak's plug has an even 235 shots at 63 weighed grains of 209 powder behind a 195 grain Barnes Expander. If I leaned on the Accura's liner I might be able to force the pin gauge thru, but as of now I still have superb accuracy with it. The Optima and the Kodiak are still superbly accurate with their liners and the shot counts.

In my first Optima pistol I shot out plugs like crazy using T7 50 grain pellet loads. I tried granular T7 and still had a tough time seeing 150 shots thru the plugs without thrashing the accuracy. After converting my plugs to the Savage style of liners I contacted Tom at Badger Ridge, got the stainless liners to which he refers and have been a happy camper since. I ordered 4 liners, then re-ordered so I knew I'd have plenty, but of those eight three are still in my guns and one went to another party in a plug I converted for them. I use the Winchester shotshell reloading primers exclusively.

I have no problem at all suggesting using the vent liners sold at Badger Ridge.

 

[BadgerRidge]

Thanks for the post Mr. Tom... but I wouldn't recommend forcing precision ground gage pins against anything... they will float through the hole if its too big.