Modification of the TC Speed Breech

[sabotloader]

The process started out to simple make a modification in the Triumph breech plug, by opening the flash channel to 0.159? from 0.125? and to exchange the 0.028 flash hole with a Lehigh Vent Liner. Sounds simple, then I decided I should find out more about the gun.

I took all the measurements off the Speed Breech that I thought might be of importance. I also decided I would try to see what the Head Space might be and how all of this came together when the gun was closed.

The Speed Breech may be the longest breech plug on the market, measuring 2.073? inches long + or ? a couple of thousands. This length aids in reducing the blow back pressures felt on the nose of the primer after firing. It also might create a problem in getting heat and pressure to the powder in very cold temperature.

When the Speed Breech is inserted and turned into place and the gun is closed, I thought for sure there would be a gap between the top of the breech and the receiver block. I could close the action with a 0.0015 feeler in between the block and BP but I could not pull it out after the receiver and barrel were closed. It really surprised me how close that tolerance was.

As I looked at the block I also noted the firing pin bushing does stands out approximately 0.014? longer than the block. I measured the primer pocket depth at 0.230?. I inserted some Teflon tape in the bottom of the primer pocket pushed a w209 down onto top of the tape and closed the action. The primer rubbed the pin bushing upon being closed and it did press fit the primer onto the Teflon tape. Opened the gun and pulled the primer and re-measured the primer pocket at 0.224?. That works to be a 0.006? difference. TC got this one very close to being perfect. Because of this measurement there was no sense in worrying about head space.

I also found out that over time the slotted head in the pin bushing on the hammer side can and will work loose allowing the bushing on the breech side to push its way back out and increase the head space. It this has been going on for some time you may now have a hard deposit built up in that area that will not allow the bushing on the block side to protrude as far as it should. Make sure you are cleaning and doing the maintenance on the firing pin.

Finally this morning I did get to the shop to work on the modification of the breech plug. One thing I would like to say is that I am not a machinist ? not even close? There is no doubt in my mind that there is probably a better way to accomplish what it did and the manner that I did it. One thing keeping everything ?plum? in a simple drill press like I have is a challenge (for me at least). There is also no doubt that a machinist with a lathe could and would do a better job.

Here is a pictorial of what I accomplished. The job is complete and the breech plug is installed and ready to go shoot. Should get that done Thursday or Friday.

One last point? the TC Speed Breech is the hardest breech plug I have ever drilled out. I believe it is a quality metal and it probably been through a hardening process. So if other are going to attempt this make sure you have sharp bits, cutting oil to help keep the temperature down and work at it slowly? Keep the temp to a minimum.

 

[Confederate rifleman]

What is this world coming to?Headspacing a muzzleloader...( lol )

 

[GM54-120]

What is this world coming to?Headspacing a muzzleloader...( lol )

Yep things have come a long way. All of mine are head spaced for a slight crush with a few primers. It sure makes the Knight breach clean.

Bellm has been offering firing pin bushing shims for head spacing some T/Cs for a while now.

 

[sabotloader]

What is this world coming to?Headspacing a muzzleloader...( lol )

The old saying takes precedent here...

"Cleanliness is next to __________" and head spacing leads to cleanliness...

 

[k]

looks like you've done a nice job on a fun project,but i think i'll wait till i have some kind of problem with my triumph's BP before fixing it....karl

 

[tpcollins]

I'm trying to understand what the advantage is by adding a vent liner? The stock plug would have a concave end with the flash hole being closer to the flash channel whereas it looks like the vent liner would make the end convex and push the flash hole opening further away from the flash channel. I must be missing something here.

 

[sabotloader]

I'm trying to understand what the advantage is by adding a vent liner? The stock plug would have a concave end with the flash hole being closer to the flash channel whereas it looks like the vent liner would make the end convex and push the flash hole opening further away from the flash channel. I must be missing something here.

There are two real advantages...

1, the size of the flash channel is inceased to help with a more efficient burning of the primer. More heat and pressre gets to the powder quicker. It also increases the volume of the chamber - reducing the amount of blow back pressure on the nose of the primer. The increase in size of the channel allowing the primer to burn more efficiently also significantly reduces the caebon build up in the channel.
2. the addition of the vent liner increases the size of the flash hole allowing a better ignition of BH-209. By placing the Ventliner out as far as possible on the eng of the plug, it adds ro the volume that the pf blow back the flash channel can hold again decreasing the amount of pressure on the nose of the primer and reducing blow back mess in the breech.

BH or any powder does not need to be right on the end of the primer if the breech plug works effeciently. Another reason i was shooting in the 8* degree weather - to test that theory...

Check this thread out also....

http://www.modernmuzzleloader.com/phpBB ... hp?t=19127

 

[ronlaughlin]

.....................................1, the size of the flash channel is inceased to help with a more efficient burning of the primer. More heat and pressre gets to the powder quicker. It also increases the volume of the chamber - reducing the amount of blow back pressure on the nose of the primer. The increase in size of the channel allowing the primer to burn more efficiently also significantly reduces the caebon build up in the channel.
2. the addition of the vent liner increases the size of the flash hole allowing a better ignition of BH-209. By placing the Ventliner out as far as possible on the eng of the plug, it adds ro the volume that the pf blow back the flash channel can hold again decreasing the amount of pressure on the nose of the primer and reducing blow back mess in the breech.................

Well, if these statements are correct, i have been doing too much work to these plug. You went to too much work on the speed breech also.

What one should do to the QRBP, and the Speed Breech to make them more reliable, is drill out the flame channel with a #21 drill, or a #22 drill, or maybe a 4mm drill, or maybe a 5/32" drill, but not run the drill through the flash hole. Then drill the flash hole with a #67 drill.

When those 2 steps are taken, will the plugs then be 100% reliable igniting BH? If so, what a simple solution is at hand for CVA and Triumph owners. When and if the flash hole gets too large because of erosion, a vent liner can be installed to prolong the life of the plug.

The flash hole of the QRBP is already at the end, so adding a vent liner is superfluous, since it won't increase the volume of the flame channel. Actually, because the flash hole of the vent liner is longer than the flash hole of the OEM plug, installing a vent liner reduces the volume of the flame channel. Adding a vent liner to a QRBP is not only more money, but could turn out to be detrimental.

Are you sure just enlarging the flame channel and the flash hole will make the QRBP 100% reliable using BH? Are you positive?

 

[jsteurrys]

What one should do to the QRBP, and the Speed Breech to make them more reliable, is drill out the flame channel with a #21 drill, or a #22 drill, or maybe a 4mm drill, or maybe a 5/32" drill, but not run the drill through the flash hole. Then drill the flash hole with a #67 drill.

Exactly, then when the orifice erodes install a vent liner or may be CVA will have it fixed by then. This is exactly what I am doing to a guys at work that was unreliable.

 

[ronlaughlin]

What one should do to the QRBP, and the Speed Breech to make them more reliable, is drill out the flame channel with a #21 drill, or a #22 drill, or maybe a 4mm drill, or maybe a 5/32" drill, but not run the drill through the flash hole. Then drill the flash hole with a #67 drill.

Exactly, then when the orifice erodes install a vent liner or may be CVA will have it fixed by then. This is exactly what I am doing to a guys at work that was unreliable.

Keep us posted. It would be cool, if this is all it takes to make the CVA plugs reliable.

 

[tpcollins]

If all of this work is just to be able to shoot all day without cleaning the flash channel, I'm not sure if it's worth the effort. I have a 1/8" drill bit with a nylon bushing glued to it for the depth of the flash hole and it's not that big of a deal to run it into the bp. I have to open the action anyway to get the spent primer out so it's right there in front of me.

I sent my speed breach to Ron at Modern Powders and the flash hole was drilled out to .035" and it works great. I bought a second plug as a back up and had the same thing done to that and they both work fine. With the rings at the end of the plug and the anti-sieze grease, I don't get any blowback when I open my action. I admit I don't understand what would cause the end of the plug to errode. Does it have to do with the powder burning next to it all the time or does it errode due to the lack of proper cleaning?

I have a 35mm film canister filled with a bp solvent and after a couple shots, I switch to my spare bp and soak the one that's dirty. After a couple shots I clean the one soaking and switch their places - never an issue. But I also swab between every shot as I like a clean barrel every time - even with BH209. But that's just me.

 

[Anonymous]

I have yet to have a misfire with the Triumph Speed Breech plug with BH209. It is unmodified. It also spits out clean primers when fired.

I like reading about the breech plug modifications on here though. Hopefully CVA has someone spying in on here and they can come up with a better plug design for 2011.

 

[coh-1]

Don't worry I'm sure CVA will copy the plug because they seem to copy everything else TC's does that is a success.

 

[ronlaughlin]

Don't worry I'm sure CVA will copy the plug because they seem to copy everything else TC's does that is a success.

Actually the QRBP is a CVA product, not a copy of anything TC. Actually the QRBP is better than the Speed Breech in some people opinion.

 

[k]

Don't worry I'm sure CVA will copy the plug because they seem to copy everything else TC's does that is a success.

Actually the QRBP is a CVA product, not a copy of anything TC. Actually the QRBP is better than the Speed Breech in some people opinion.

well i don't know anything about cva breech plugs but my triumphs plug has allways fired blackhorn 100% down to 9* and has always been 99.9% blowback free.i would have said 100% but after 20+ shots it will get a little dust past the primer, then i use a 1/8" bit to clean.i do not use teflon tape or grease on the plug,just a light coat of oil.it has never become stuck or been hard to remove shooting either BH209 or T7.if a cva plug has to be modded to shoot BH209 how could it be a"better"plug.....karl

 

[muzzlenut]

I?ve been very confused reading all the posts about the Breech Plug problems with BH209 and all the methods to remedy the problem. I shoot an Apex .45 cal and since switching to BH209 & CCI 209M primers I have not had a mis-fire or no-fire and I do not clean the flash channel until the end of the day. My range sessions usually last from 15 to 33 or more shots. Altering the BP to make a smaller powder pocket in front of the flash hole seems to be the latest solution.

ronlaughlin wrote:
"Your observation of the 'smaller chamber', which reduces the volume of powder catching the primer flame is quite astute. What ever the reason, this modification of the QRBP, makes for reliable ignition of BH first time every time, thus far."

?ronlaughlin?, the following may validate the theory of the smaller powder pocket.
Jan. 4th I went to the range, swabbed the barrel to remove oil, and fired 3 primers off to foul the barrel. I then fired 33 rounds through the Apex .45 cal. I did not clean the the flash channel at all during this session. I did not clean the gun that night deciding to clean it the next day.
Instead of cleaning it the next day, I decided to go back to the range. At the range I loaded the Apex .45 and started shooting 23 rounds without cleaning the flash channel at all during the session. I completely cleaned the gun that night.

 

[muzzlenut]

My copy/paste didn't get all of my post. Sorry!!!!


I had no mis-fires or no-fires at all during both of these sessions. Is fact that I?m having no ignition problems relating to BH209 because I?m shooting a .45 cal. instead of a .50 cal?

 

[sabotloader]

muzzlenut

I had no mis-fires or no-fires at all during both of these sessions. Is fact that I?m having no ignition problems relating to BH209 because I?m shooting a .45 cal. instead of a .50 cal?

I really do not think that the caliber, well at least 45 to 50, would play a major role in your success.

I have not had a mis-fire or no-fire and I do not clean the flash channel until the end of the day. My range sessions usually last from 15 to 33 or more shots.

I think there is more than one varible in the equation that makes some guns work very well with BH and others not. I would also suggest the biggest reason for some of the problems is the current breech plug designs. In your case if your Apex plug is working well shot after shot and over many shots - I might suggest it could be the type of primer you might be using, the weight of the projectile that you are shooting, even the fit of the sabot. One other thing I am finding is that climatic conditions can also effect the operation. Temp and humidity might even be a couple of the key items.

Altering the BP to make a smaller powder pocket in front of the flash hole seems to be the latest solution.

Not necessarily, the conventenal wisdom says to get the powder as close to the nose of the primer as you can, sorta like make it as close to mimicking a shell as you can. In my little world I some what disagree with this as it increases the blow back pressure on the nose of the primer. If your rifle can be head spaced for the different primer lengths this would not be as big a problem as the primer would be held in place to prevent leakage.

The biggest problem I have encountered continues to be the closing down of the 'flash channel' as you continue to shoot. One thing that I think is working for me is making the channel larger in diameter allows the primer to burn more efficiently and hopefully cleaner leaving less debris in the channel. I feel the combination of the hot blow back gases entering the flash channel and the cooling debris left in the channel left from the ignition of the primer combine to make a hard carbon deposit.

Just some thoughts from this side of the mountains...

 

[GM54-120]

Ive tried several designs and the one thing i found in common with the best is...proper primer fit. If there is almost no blowback or blowby then the channel stays cleaner longer. Mag primers are a bit dirtier but that goes with the territory. I avoid them if possible.

Another thing ive tried but i seldom see mentioned is...polishing the flash channel with JB or jewelers rouge (sp). If its mirror finished then carbon has a harder time sticking to it, just like paint sticks better to a slightly roughed up surface.

I tried this on the GenI Lehigh plug as a test. I polished the primer pocket and flash channel. The difference was noticeable but not dramatic since it was already very well machined for the first production attempt. I would have left the pocket alone but it was a bit sticky with some primers. The GenIIs i left alone since they worked so well but i might try it today since im bored.