Hi Ron,
Thank's for the results so far on your Mod's. The difference in impact was one of my concerns earlier in this post, ans Im sure I was quoted as there would be no difference. The other was if it really would make all that much of a difference in blowback. As you mentioned you were unsure if the difference was all that noticeable.
The minimal blowback I now have with my ACCURA was'nt that much to worry about to begin with, and now I tried a rubber O-Ring behind the primer it seemed to make some what of a difference and lessened the blowback. The little extra cleaning, mabey 2 minutes to remove the small amount of blowback from the firing pin area does'nt make or break me as I always take out the firing pin and spring everytime and clean it anyway as I want the ML CLEAN and I am a clean freak.
So for now Im gonna just stay with things the way they are as there not that bad, and I have My ACCURA shooting 1"groups at 100 and 2"groups at 200 so Im not gonna mess with the BP. I have extra new BP's for it so when they get a little wore I'll just replace them. Let us know how things work out with your other BP's and the ACCURA's.
I was considering buying the (New ACCURA V2) when they came out but Im not sure I will now as the ACCURA (Older Version) are pleanty good for me and preform well. A new BP with the ACCURA V2 was all I was looking for and Im still undecided if just that alone will be enough for me to purchase one.
Heck the older ACCURA Camo/SS can be purchased at Cabela's now for $329 and with the new Cabela's offer's I can get another $40 off that price so for $289 you get a great ML at a Great Price. Not that I need another as I already have 3 of them.
Chances are I will buy the new V2, just to see if the difference between the 2 are really that big. It does'nt bother me to take 15seconds to remove the BP now so a quick release one, so what, and the recoil burner's just dont appeal to me either.
So for now Im usdecided but still very happy with the older ACCURA's. Thank's again for your report Ron and fill us in on the rest of your results.
(BP)

BP i have a V2 coming my way as soon as they are available, i'll be the guinn..... Er.. Tester on how the New plug works out.

MD, I e-mailed Mark %$#*&^@ and just about begged him for a CVA Pro Team Hat and said I'd pay for it and he never even returned my e-mail, Im dissapointed! CVA has them and give em away all the time but I guess Im not worthy even though I have been a CVA shooter for 20years+. Anyway I'll let you have all the glory with the new V2, when do you expect them to be available?
As long as I get mine by mid Spring It'll be enough time for me to see weather or not Im impressed.
(BP)

Went up into the hills to try out the Savage vent liner in the Accura this morning. I fired the rifle 15 times. Results for the Savage vent liner were similar to the results with the Lehigh vent liner. The blow back may be less than the factory breech plug, but i can't really tell.

Both vent liners seem to make the rifle shoot higher. Both vent liners have been reliable in these limited test.

I loaded the rifle with 105g BH209, 300g 44 caliber xtp, smooth Harvester sabot, and W209 primer. The range was about 98yd. The last 4 shots i fired this morning are shown on this picture of the target:

Thank's for the update Ron, have you tried less powder in your ACCURA? from the groups it seems like they could be pulled closer. Or were you just testing the results from the BP's? I also tried the 300gr .44cal XTP's and wer'nt happy with them, this was a long time ago. Since then I changed to the .45cal 240gr XTP Mags, and also the 45.cal 300gr. XTP Mags, they shoot perfect out of My ACCURA and other CVA's. Keep us updated on any further results, again Thank's!
(BP)

Ron, also I can only assume that the higher groups are caused by the more instant or directed ignition with the vent liners, other than that Im stumped.
(BP)

I took Sabotloaders advice and tightened up the BP on the ACCURA a little more than I usually do, kinda tight with Teflon Tape on it. I also put a rubber O-Ring under the Primer. This made a Big difference. Blow Back was minimal and only on the firing pin face area, one little wipe and it was clean. So for now Im going with this was and I wont have to adjust for elevation if I modify the BP with a vent liner.
(BP)

Hunting season ended for me yesterday; this morning i modified 3 more Accura breech plugs.







It didn't take me very long even though i am not a machinist. Here is how an old carpenter works these breech plugs.

First thing is to measure the diameter of the Accura breech plug.



Then clamp a block of wood to the drill press, and drill a 5/8" hole in the block with a forstner drill, which leaves a flat bottom hole.







Then one needs a way to keep the breech plug from spinning in the hole whilst being drilled and/or tapped. This can be done by using a 'set' screw on a 'flat' of the hex end of the breech plug.








Then a 3/8" drill is installed, and the belts of the press are set for the slowest possible speed, and then used to drill the 'powder pocket' in the breech plug. Oil is used to keep the drill cool, and help it cut.









Next a 25/64" drill is installed and used to slightly enlarge the pocket and to form more of a 'seat' for the vent liner. It is possible and reasonable to eliminate the 3/8" drill and just use the 25/64" drill.





Now it is time to use a counter sink to accurately form the 'seat' for the vent liner. Oil is used so the counter sink can be used again.





Here are pictures of the process to drill out the flame channel so it can be tapped to receive the threads of the vent liner. First a 9/64" drill is used, then a #21 drill, along with plenty of oil.








Now the plug is ready to tap. The drill press can be used to hold and align the tap if the belts are disconnected. Then the tap is turned by hand. Oil is used to assist the cutting, and the tap is turned about 8 times.
















The finished plug

Very nice Ron, great photo's.

ronlaughlin

With your modifications it is probably possible that you are getting a better burn and you have increased your velocity.

sabotloader

Wouldn't that be nice if the modified BP is more efficient. One could use a chronograph to check speeds and maybe answer your question. Perhaps i should do this in the spring.

I can tell you i shot a modified BP in a Knight DISC yesterday and the velocities did bump up right around 75/100 fps with a 110 grains of T7.

Thank's for the Pics and up-date Ron, I've been waiting for your results......as seen the modified BP looks to be more efficient. If you chrono it Ron let us know if you get more fps. I talked to Mark today at CVA and he seems exicited about the new ACCURA V2 and it's new BP design. After our talk I think he purswaded me into the new V2, I'll be getting one soon. I was a little hesitant but I think CVA may be onto something........
(BP)

Did you get yer hat? :D

I'll have to see....I submitted a few pics of me and My ACCURA and My Deer to CVA. If they are chosen I get a Cap......MD, have you tried a Rubber O-Ring behind the Primer in your ACCURA? It made a Big Difference to mine, Blow-Back is all but eliminated!
(BP)

i havent found an o ring in my local hardware stores that will fit, they are all way to thick. i'll have to see if my dad carries o rings on his service truck.

Been going up into the hills every morning to shoot my rifles. It has been around 10* to 15* in the morning when we wake. Have been shooting 105g BH209, lit by W209 primer, pushing a 44 caliber 300g xtp, in a smooth Harvester sabot.

In the Accura, i have been using the middle plug in this picture; it has around 50 rounds on it now.



Usually i shoot each rifle 5 to 10 times each morning. So far the first shot in the morning has lit instantaneously, after the rifles sit in the cab on the truck loaded, over night. Below is a picture of some fired primers from the Accura.



One can see there is little or no blow back. After about 10-15 shots i get after the flame channel with a 5/32" drill.

Next i plan to leave the rifles sit in the cabin of the truck loaded for a few days and nights, and then see what happens when the trigger is pulled. Have to quit shooting every day, and look after some chores around here.

WOW Ron! that middle plug looks pretty clean, looks like the conversion has really helped a-lot. Now for leaving your ACCURA in your Truck for a few days. I DONT have the conversion and I Hunted in the Rain fr days at a time bringing in the ACCURA each night then back to the Truck and into the Rain again, I never had a problem with it firing. I also Hunted in Below Zero Weather and have taken the ACCURA in the House every night then back to the Warm Truck, into the COLD back to the Warm Truck and Home to the Warm House again and reapeted this process untll I have pilled the trigger, and each time it fired. I do cover the end of the Muzzle with Masking Tape and I believe this is the most Important Part of keeping Moisture out. And even thought the break open action IS'NT protected except for the MLer's design, it also has'nt let any Moisture into the BP. So with your conversion and IF you keep the Muzzle Covered you should have no problem.
I really like your results and I should have My BP converted as you did. Keep (US) up tp date on your results and Thank You for your time doing this, I really appreciate it and so do other ACCURA Shooters.
(BP)

Ron Laughlin
I have been sitting here contimplating the idea of why I need the NEW ACCURA V2 after your findings.......I Love My ACCURA's (3) and if your findings with the BP conversion work as you say they do them Im really thinking of just upgrading My BP's as you did. Im not sure Im sold on the new ACCURA V2's design with the rubber on the forearm and stock, I think it's ugly.....the new BP is what I was in it for. If I can get your results I'll just do that and save myself some cash in getting 2 new V2's (for me and my Wife) as I have to get her on too as she'd say I was trying to have an atvantage over her and she's still trying for the (BIgger Buck on the wall), but if I can help it, it will never happen, but God Bless her if it does, (Rotten ME!)
Im just sold on the (Old) design of the ACCURA and if I can make it all that it can be I will. But we all know how that goes, we just cant Stop Buying the Newest Better MLer. It's not that I cant afford to buy 2 more, it's I like what I have and why change what works, Plus Im sure the one ACCURA I have now is a real Shooter as the groups it shoots are unreal, even thought there's a little blowback, but the rubber O-Ring solved most of the problem, and if your conversion works as you say then Im really in for what Im looking for.
Let's see some more results...................
(BP)

I am new to ml hunting. I just purchased an Accura about 2 months ago. Now, can someone please tell me if my Accura has the new bp or the old style, and how can I tell the difference?

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!:fighting0007:
(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.

Screwbolts

Thank you for your reply. I will give the 'C' drill a try, if it is necessary, to be able to close the breech with an O-ring in the primer pocket. Installing a 3/8 bolt in the breech plug and milling a new smooth primer pocket interests me, but i don't think it would work in either the Accura or the Omega. To me, it doesn't seem possible to get a socket on the bolt and into the barrel of either rifle. The socket, if my brain is working correctly, won't fit into the opening in the barrel which receives the breech plug. These breech plugs aren't so very expensive, so using the O-ring to slow the flame erosion, then after the erosion is too much, replacing the breech plug may be the way to go. Thanks again.

Ive been following this thread and have modified my Accuras BP like Ron did ,I havent shot it yet. I tried putting the oring into the primer seat and the primer was pushed up pretty high, I tried to close the breech and it didnt want to close completely and I didnt want to force it .Im curious to see how you make out with this,if you have to drill the pocket any to utilize the o ring in the Accura.

RonL, When I use a bolt I remove the bolts hex head after It is screwed threw the breech plug, this leaves me with a 3/8, .375 stub to shorten or cut to length on both ends of the plug. The plug still retains the same system for removal as it had originally.

Here is a photo of my Rolling blocks plug, you can see some threads exposed on the primer end. This was one of the first plugs I did and at the time I was not treading all the way threw with the tap and would jam the bolt against the end of the threads cut my the tap locking it in place. I now thread the plugs straight threw and use the end of the threads on the bolt to jam/lock the bolt in place, this leaves no threads showing. I am going to cut/fit the nose end of the plug anyway so why not cut the excess threads off, this leaves a much neater job.

[IMG]http://huntingnet.com/forum/

Some photos showing my mods to a rem 700Ml breech plug.

Plug with bolt fitted, bolt is always a little long to allow fine tuning:biggrin:

[IMG]http://huntingnet.com/forum/
This shows same plug with both ends of bolt trimmed, still way to long but a start.

[IMG]http://huntingnet.com/forum/



This the vent end with liner now installed



[IMG]http://huntingnet.com/forum/

Screwbolts

Aha, it appears i will not be tossing any worn, flame cut breech plugs. Thank you for the explanation, and the explanatory pictures.

Haven't really felt the need to use an O ring in my Accura too much, but here is what i did to the worn Omega breech plug pictured.







This breech plug has seen many rounds, and also has been modified and fitted with a savage vent liner. It hasn't seemed to be as accurate as a new unmodified breech plug, so i figured i would toss it.


Screwbolts suggested i drill the primer pocket deeper using a letter C drill which would allow the use of an O ring. I tried using an O ring in the damaged breach plug without drilling it, but couldn't get the action to close. So, i followed Screwbolts advice; purchased a letter C drill, and drilled the primer pocket some deeper.





Here is what the breech plug looked like with the O ring installed. It fits nicely, and doesn't want to fall out. The O ring is 1/4" outside diameter; 1/8" inside diameter, and 1/16" thick.






This morning i headed up in the hills, and fired 7 shots with the Omega, and the modified breech plug, with an O ring installed. The load was 105g BH209, a 300g 44 caliber xtp, a Harvester crush rib sabot, and a Federal 209A primer. Following is a picture of the 7 spent primers, and the used O ring as well, along with a new O ring.





One can see there is zero blow back when using the O ring.

The accuracy wasn't very good today though. The pictured target was shot yesterday using an unmodified Omega breech plug (yellow holes), and today using the modified breech plug with the O ring, and the savage vent liner installed (green holes). The range was about 102 yard, and the air was about 30*, with no breeze.





To me, it doesn't seem worthwhile to install a vent liner in the Omega breech plug. In my brief experience, the standard Omega breech plug seems just about perfect as is. However, once the breech plug has been used a lot, and suffers from flame damage in the primer pocket, it would seem that using the 'C' drill, and then using an O ring will extend the useful life of the breech plug. Perhaps there are those that will want to use an O ring in a 'new' breech plug, so there is zero blow back. My guess is the addition of an O ring shouldn't affect accuracy, unless it makes it better.

Hi RonL, for some reason your photos didn't show for me :-(

Ken

Sometimes i have to hit the refresh or repeat button to make the pictures show.

Thanks for the tip!! It worked!!:cool2::cool2::cool2:

I started with the old cap lock, moved to the Knight disc and moved up to a Encore and than to a Traditions Prusuit and on up to the first style Pro Hunter. The latter being my pick out of every ML I've had the pleasure to own. The Knight had few different style BP's meaning the fire path was larger or the back of the BP was more open or the back was split supposedly to help lignite the powder. The Traditions if the BP got worn you have to pry the primer out. All these ideas in my opinion came to a head w/ the Encore/Pro Hunter that will all but flip your primer out. The Idea of being able to remove the BP w/ my hand does influence me to not ever buy a ML that has that feature. If I can't carry a BP wrench then I shouldn't be hunting. It also allows for more blow by. Manufactors need to forget the speed breech and move on to other improvements. The thing to remember is what ever BP you have is keep it clean and the threads greased or taped. If the ML was designed w/ that plug then you might improve it but in the end is it worth the expense. The main thing in my book is the speed I can remove & replace a primerbecause w/ a 209 misfires are rare.