the brand new accura has a finger removable breech plug. yours most likely used the tool to remove the breech plug.

just an opinion but none of this (entire topic) needs to be done to the breech plug on the cva rifles. Certain primers are just filthy and they leave a lot of "carbon"? build up in the flash channel. I used cci inline mzl primers today and the flash channel is super clean. with remington sts primers they build up crud fast and then i'll get one primer that goes plop and leaves a mess inside my rifle.

shoot your accura as it is and dont even worry about this vent liner stuff.

It has the (Old) style BP, I talked to Mark at CVA a couple of weeks ago and the new ACCURA V2 wont be available from the Dealears untill mabey March, you can get one from CVA now but you'll probably pay $150 more for it.
As MD mentioned just shoot your ACCURA the way it is and dont worry about blow-back as it is minimal at most. And if you want to try what I did get some rubber O-Rongs and put one behind the Primer and you'll get very little blow-back, or go with a vent liner if your really (picky) about it (blow-back) but for now the way the old ACCURA's are Im Happy, but I will get a New V2 just because........I guess when you get OLDER you like to BUY things you like,,,,,,,Mid Life Crises, mabey........your times almost up......I hope NOT! ADDITION to MLers, YES, because we need another one, NO..........Just SHOOT your MLer, ENJOY LIFE and BE HAPPY, That's what matters MOST!
Dont let the little things that you think matter spoil you FUN!
(BP)

Thanks for the info MD54 and BP. As soon as the weather breaks, I am going to start shooting. Yep BP, I don't need another gun of any kind, but as I get older (75) I still want to BUY, because I want it.
Good Luck and good shooting to both.

God Bless You Cozumel, Im glad your still able to do what you love! If you need any advice on loads let me know and I can help, I have 3 different ACCURA's all set up with different loads.
Also on Sabotloaders advice I've been using Teflon Tape on my BP, and snug it up pretty good, plus I've been putting a Rubber O-Ring behind the Primer and Blow Back is almost nonexistant.
Best of Luck to You!
(BP)

One of the Omega breech plugs i modified seemed to be allowing more blow back than i thought it should. I replaced it with another, and when i examined the replaced plug, i saw this:







I don't know if that worn looking area in the primer seat was there when it was new, or if it was made by some kinda flame erosion. Either way, a primer seat that isn't real smooth, uniform, and nice does allow 'blow back'.

The unaltered new breech plug now installed in the Omega has much less 'blowback' than the one pictured. In the future, i guess i should examine all breech plugs before i modify, or use them, and if they don't have a nice clean uniform primer seat, they will be returned. If this area on the pictured breech plug is from usage, not milling, i guess, perhaps, one should be using o-rings to increase the longevity of ones's breech plugs.

I believe, what you found in the seat is flame cutting from the primer. I found that the CVA/BPI breech plugs would start to develop the grooves some ware less than 200 primers. At one time I believe CVA/BPI recommended that the plugs be replaced every 400 primers. In working with CVA, Remington, Knight, Lyman/Pedersolie, and my own from Grade 8 bolts. the CVA were the softest most easily machinable material. This might be why the erosion starts so soon.

The o-ring might be a good plan for the plugs to help stop or slow down the starting of the erosion. The plug you have now that shows the erosion could have it's primer pocket deepened and that would clean up the erosion and allow space for the o-ring. this would definitely lengthen the service life of the plug. If the plug then developed more erosion, you could replace the primer seat by drilling and taping the plug for a short length of 3/8x24 grad 8 bolt, then make a new primer seat in the bolt with a C size drill. I would recommend purchasing several C size drills from different makes, this will allow you to fine tune the actual diameter of the hole for your primers. I have 3 different C size drills and they all differ slightly in size, something about with in normal limits +/- . When doing this I run the bolt clean threw the plug so the vent liner is fitted in it also.

Screwbolts

Thank you for your reply and suggestions. I agree that the 'groove' in the primer seat is from flame cutting. After i made my post i examined the breech plug more closely, and saw evidence that there was a hole being bored sideways through the breech plug by the 'flame'. The flame cutting in that area may have occurred because of a milling defect, but now it is definitely being cut deeper and broader by 'flame'.

My brief experience modifying breech plugs, has shown me that the material of the CVA breech plug is definitely 'softer' than the material of the TC breech plug.

Another question that entered my brain is if drilling the flame channel all the way through the primer pocket is a mistake. I am wondering if when one drills through the flash hole with the #21 drill in preparation of tapping for the vent liner, if one shouldn't stop short of going all the way through the end of the breech plug. This would leave a broader 'ledge' for the end of the primer to sit on, and perhaps help reduce blow back and thus the 'flame cutting' of the seat.

I just spent a little time searching for the 'C' drill, and found there are two types commonly available. There are 118* and 135* drills. If i correctly understand the nomenclature, what i should purchase is the 135* C drill, which i believe would be the 'flattest'. However, this doesn't seem flat enough to mill a primer pocket. After purchasing these drill, will i then need to grind the tips flatter to make a more better primer pocket?

I believe your choice of 135* would be fine. I normally just leave the seat as the drill cuts it. Being all the primers I have seen have a non square corner, a rounded corner to seal against the seat, gas cutting is going to happen as long as there is leakage. If a rifle has a bolt to close against the primer it can be set to slightly crush the primer for a better seal, but in the case of the break open guns, there isn't anything to cam the primer in tight. Being primers of the same make very in length, the o-ring might be the bestest possible solution. The o-ring doesn't seam to cause a problem by not allowing the action to fully close, it is very forgiving. And that should help stop the cutting and help with the fit of varying length primers.

I have always drilled straight threw and then tapped the hole to 10x32 for the vent liners. This is how the Savage plugs are made from the factory and they hold up great. they are made of I believe 4140 chrome moly steel the same as CF rifle barrels. I have not found any flame cutting in the savage plugs, but the primers are crush fit in these guns. My Remington Rolling Block that I built for smokeless use has breech plug made from 5/8 Grade 8 bolt. This rifle has fired over 800 primers and there is still no sign of gas gutting in the primer pocket. Because this rifle has a rolling block it closes very much like a break action gun, it only holds the primer in place no crush fit.

I recently complete a conversion on a Remington 700ml to sealed 209 ignition. I fit the bolt with a 25 ACP shell holder to hold the primer. I bushed the firing pin hole in the shell holder to .120. The I turned the last .450 of the firing pin down to .110. this is similar size to a shotgun firing pin. I modifed the Rem breech plug by fitting it with grade 8, 3/8 x 24 bolt. this alowed me to make the primer seat and fit the plug with a Savage style vent liner. ( I drill my own Halo Chrome 10x32 x 3/8 screws to make vent liners) I fit the plug to my batch/lot of Winchester primers so that the shortest primer is crushed .002 and the longest would be close to a .010 crush. Before I returned the rifle I shot it over 80 times and had no blow back and allot of fun shooting. The owner of the rifle stopped by to pick it up and we shot it 25 more times that day, he was thrilled with it's performance and I showed him how to drill out the breech plug to clean it. The rifle arrived to me with a #11 nipple in the breech plug. it left with a blow back free 209 ignition system that will fire BH209 every time. This rifle had been neglected and even thou it was SS the barrel was badly pitted, the BP was even badly pitted. I couldn't believe how good this neglected rifle could still shot using 90 gr V BH209 and Harvester Sabots with my cast 333 gr LBTs or even with TC Cheap shots and the same load.

nice report Ken, Im learning a-lot.......you too Ron. Keep up the good work both of you's. Have either of you's figured out why or how the modified BP shoots groups differently then the unmodified BP's? Is Accuracy as good or better with the modified BP's?
(BP)

I modified my Omega breech plug, because i was interested in seeing if the modification would reduce blow back, not because the factory supplied breech plug didn't work. Thus far, i have fired around 75 shots through the modified plug. Right or wrong, i began to think the reliability was worse, the accuracy was worse, and the blow back was no better. I have had to abandon the modified breech plug in my Omega, because i had no faith in it. I am now shooting the unmodified factory Omega breech plug, and feel comfortable with it. I may try o-rings under the primer, and if they work, see how that goes. If they won't fit, i will use a C drill and increase the depth of the primer pocket some, so an o-ring will fit.

The muzzle end of the factory breech plug of the Accura is much different than the Omega breech plug. The Accura has worked quite well with BH209, but once in a great while it had hangfire, and once it had a fail to fire. The Accura breech plug with the vent liner installed, has been 100% reliable so far, and has been accurate, but the blow back hasn't been any better than the factory breech plug. The blow back in the Accura has always been less than the blow back in the Omega. I may give the o-ring a try in the Accura, or i may not; blow back in this rifle isn't much of an issue.

My early conclusions about installing vent liners in these breech plugs aren't really worth much, because i probably haven't shot more than a total of 250-400 shots total through these rifles. It does seem like i have gone through boxes and boxes of primers, and bullets, and several bottles of powder. I have come to have an opinion, even though there isn't really enough data to make strong, valid conclusions. To me it seems the modification of the Omega breech plug is unnecessary, but adding the vent liner to the Accura breech plug allows for a deeper powder chamber. This seems to be be more reliable than the factory breech plug design is, when using BH209.

I am also inclined to think using W209 primers may be more of the cause for the hang fire, and fail-to-fire in the Accura, than the breech plug. I am inclined to believe that Federal 209A primer used in the Accura might give 100% reliability, but this is just a thought. I am now using the 209A primer, because it makes me feel better.