Mingbogo,

Great stuff thanks for posting.

You have a PM!

Regards,
Dave

Mingbogo-

That is beautiful.

In the comparison shots of the different safety shrouds you have at the bottom the issue CZ shroud, the above that a military shroud, then above that, Mr. Burgess' shroud with firing pin and the other shroud. What is the origin of the one on the top; it is also on the far right in the other photo.

Thanks for posting the photo's.

Mark,

That shroud is from Jim Wisner. Although, Jim makes some nice parts, I like Tom's version better because it resembles the original 98 with a front gas shield. Thanks.

quote:

Originally posted by 30 Caliber Mag Fan:
Mingbogo-

That is beautiful.

In the comparison shots of the different safety shrouds you have at the bottom the issue CZ shroud, the above that a military shroud, then above that, Mr. Burgess' shroud with firing pin and the other shroud. What is the origin of the one on the top; it is also on the far right in the other photo.

Thanks for posting the photo's.

[QUOTE]Originally posted by Mingbogo:
Mark,

That shroud is from Jim Wisner. Although, Jim makes some nice parts, I like Tom's version better because it resembles the original 98 with a front gas shield. Thanks. "


I am just curious if that Shroud/Safety is strictly a custom item available only on a special order basis from Mr. Burgess, or whether he has those in stock and they can just be ordered. I am also curious as to what they cost, and whether they are also available for Masuer actions?

Just got some pictures from Tom in regards to some additional modifications that he can do on the CZ 550, including the bolt handle, etc. that he did not do on my action.

If any of you have a question regarding his safety and trigger, please fire it up right here, as I am sure Tom will jump in to answer it.

Cheers!

quote:

Originally posted by Mingbogo:
Just got some pictures from Tom in regards to some additional modifications that he can do on the CZ 550, including the bolt handle, etc. that he did not do on my action.

If any of you have a question regarding his safety and trigger, please fire it up right here, as I am sure Tom will jump in to answer it.

Cheers!

I want one!!!!

That sure makes the 550 look a bunch better. I hope Mr Burgess jumps in and shares the details such as cost and timeline. I have 3 550's that could use his treatment.

Great Pics.................I would love to have those mods done to all my cz's

I would be very interested in having Mr. Burgess install his safety and trigger on my CZ550...how does one go about contacting him?
Thanks in advance.

Trigger units for the CZ Mod 550. I made 4 of these, 1, for total sacrifice, the other 3 hoping I would get 1, I could live with. The original inclination was to make some sort of adapter for it to fit the older ZKK's. I had only Mingbogo's action to work with. He had asked me almost in passing to fit some sort of unit if one was available. When I looked at a Blackburn trigger made for the '98 Mauser and Canjars made for other rifles it belatedly occured to me that all these units carried a separate sear and that much like what was already present in the CZ. So why make a trigger unit containing one if there was a useful one in place? That led to a housing not unlike the Mod 550 unit minus almost enough parts to outfit a pistol. I took a chance and made 4 housings as noted. It soon became apparent that 2 different triggers would be needed for the M 550's The guard bow on the Magnum requires a trigger bar with longer reach .It is deeper in that area and you cannot balance the trigger bar on its pivot so that it is not like a single bladed aircraft propeller, and that in turn dictates a shorter housing to fit in the standard ('06 length) action. Establishing that was not the inventory nightmare it seemed to be. This is where the design took a radical turn. At this point I decided to use an ancient release principle. The fire-pin spring- extra strong in the CZ's- has some of its cocked energy applied to the sear, and that to the trigger bar. There is variation caused by fit of sear pin, the sear spring, point of contact- sear to cocking piece, etc. Lots of variables. These would have to be adjusted in the trigger bar spring. When I eliminated those variables by simply turning the applied pressure whatever that might be to friction and the let off part of the trigger bar where it contacts the sear a radius equal to its distance from the trigger bar pivot axis, the trigger unit proceeded to design itself.

How can you do that? The pressure required to release this trigger is all in the trigger spring. If you want less than 3 pounds pull use the trigger that came with the rifle. There is enough adjustment room to increase the pull to about 4 pounds. This has an overtravel stop, but that is probably useless. This because when the sear is released the spring to the trigger is still resisting movement by the same pounds pull. The next versions will have the engagement screw located on the same face as the trigger tension screw. The whole theme was to keep it simple, but truth be told I did not expect the results I obtained. All I could blurt out when I realised what I had going was, "Well, I knew that!". Knowing and believing, it seems, do not always go together. When you use a principle that the Romans used on their small throw weight ballistas ( to save chopping the rope each time), but it has not been used on the more common firearms in probably 100 years, their is always that nagging question, "Why not?" 3 units in use does not an annual production make. It could quite well be that this principle has not been used merely because no one else has and that, notwithstanding
parts locations preventing same, must have been tried and discarded by those that proceeded your design and therefor stick with what the competition is doing and avoid what you think that they found out. This trigger might well be an aftermarket install it yourself add on, by those not mechanically impaired, but the version for the ZKK's would require a milling machine to inlet it into the guard bows on them and to increase the diameter of the receiver hole for the adjusting screw to allow insertion of a permanent threaded stud which is a press fit.

I'll cover the bolt sleeve safety unit in another reply later.

Mingbogo-

On your action, is that standard CZ bottom metal or, is that a replacement unit?

If it is a replacement is it Mr. Burgess' or some other origin?

Thanks in advance.

30 Caliber Mag Fan,
Looks like standard CZ bottom metal to me.

Ming,
Thanks for taking the time to post all the great photos and good info.

Tom,
Good work.
I want a dozen of each, triggers and safeties. Please get back to work. BTW, being from Kalispell, MT, do you know what the difference between a BBK-02 (old Bauska Arms offering) and a BBK-01 (recent Ultramag action) is? Thanks.

Thomas Burgess never ceases to amaze me with his knowledge, and his engineering and machining skills. With all of his knowledge, I wish he would design and build a "Burgess" action so that once and for all we would have the perfect action.

In the meantime, I wouldn't mind having a couple of those Streamline Mauser 98 style safeties to fit a couple of 1909 Argentines I have sitting around waiting to be made into sometning.

30 cal,

The bottom metal assembly is a factory unit. It looks and works just fine for me so there is no need for a replacement. Thanks.

Hey Ron,

Long time no see bud! I posted those photos just for you since you have a few ZZKs that need a safety and trigger upgrade. Cheers!

Tom probably already have designed his own action and there are probably a few of those "one of a kind" rifles out there. With enough time and cash, I am sure Tom can come up with a prefect action or rifle just for for you.

quote:

Originally posted by 22WRF:
Thomas Burgess never ceases to amaze me with his knowledge, and his engineering and machining skills. With all of his knowledge, I wish he would design and build a "Burgess" action so that once and for all we would have the perfect action.

In the meantime, I wouldn't mind having a couple of those Streamline Mauser 98 style safeties to fit a couple of 1909 Argentines I have sitting around waiting to be made into sometning.

I'll second the request for a Burgess designed action!

Firearms manufacturers could learn ALOT from Mr. Burgess....

Regards,
Dave

Mingbogo my friend,
It is indeed good to see you around again, and bringing such good news to boot. My solitary ZKK has a Wisner safety and a proper trigger already, but I have too many CZ 550's that need fixin'. Sounds like they will be easier to do than the ZKK, for which I am thankful. At least the CZ's aren't "bassackward" in the direction that the safety works, so are tolerable until they can be fixed.

I'd say the CZ will beat the Dakota by miles if it gets a Burgess safety and trigger and a polish.

Gentlemen

Great pictures

I hope CZ factory implements these modifications and remove that billboard TEXT

Tom does marvellous work

Cheers
/JOHAN

Phase II of reply. Bolt sleeve/safety assembly. The bolt threads on the ZKK actions, increased and variably so over the long production. They are the same pitch and style as with the Mod 550. This required a selection of thread pitch diameters in oversize which I increased in 3 runs of the sleeve. As on this one of the pictures, I could reduce the thread pitch diameter for a no rattle, no end play ,smooth move fit for the Much tighter, Much improved Mod 550. It doesn't stop there , however. For the much more "generous" tolerances of the ZKK's, I had to increase the distance from the center of the sleeve to the bottoms of the gas flage where they contact the lug raceway flats. That was to make certain that the 3 d full safety lock position where the bolt locking plunger engaged the bolt wouild always align with the notch for it in the bolt body. This had to be trimmed from those sleeves I have made up and was done in the pictured example. I had also reduced the tolerance between the fire pin bore in the sleeve and the fire pin. These two things greatly helped securing a consistent trigger pull release weight. The result of making these alterations to fit had much to do with deciding to proceed with the new trigger, because it seriously reduced the variations you would otherwise encounter. It would require less fitting of sleeves made to the tighter specs of the 550 ( if they continue that way) Big plus! There is a down side? Isn't there always? Certainly. There is no way that the M 550 cocking piece can be used. The detent as on the early pre 64 M 70 Winch, was provided by the firing pin spring and the cam surface on the cocking piece for it. My Safety lever is a direct knock off of the first post war "long tailed" Winchester lever. The one which was not made from a casting. My lever could cam the smaller diameter M 550 cocking piece into the lock positions, but it would not detent using the mainspring tension and
after all of the work involved tooling and making those levers I am not about to use the current solution that occurs in the lockup of the "Big Red W" offering. The original design was simply better albeit costly to produce in quantity.. I did read about the buffalo incident on the Africa forum site.

Well, if old Tom can make all those parts certainly he can make a new cocking piece. Yup. I had invested in precision thread pitch diameter measuring micrometers just to measure the firing pin thread and a lot of sample ZKK parts. $1700.00 street. That is a lot to amortise for the market I envisioned. But then I had to know, and knowledge usually ends up making a bloody entrance. There is too much wobble and end play in the fire pin/cocking piece threads. The sample I had to work with had .009" end play in the bolt sleeve to bolt threads. Combined with the end play in the fire pin/ cocking piece threads the total allowed the fire pin to move forward from .052 pin protrusion static ( pushed back to take up the play) to .073 utilising the full momentum of the fire pin. You can get that ammount from Mausers where these same parts are loosely fitted. The effect of what could be called too much protrusion is further diminished in ammo using berdan primers. It really was not much of a problem with the boxer primers and variety of components in years past to perhaps the last 10 or so. The curent effort to reach hyper velocities means having to eliminate any source of primer piercing. That means a light interference thread fit with the new cocking piece and the fire pin thread which although as they come from the factory cannot be called a drunken thread, they are a tad tipsy. This leads to an undersized threading tap for the cocking piece thread. Currently available offerings are .0035" over the nominal size- if you can believe the "D 5" size rating of the EU Diktat. That is about.005" above what I need.
The least desirable solution was to simply make my own threading tools. At one time that is what gunsmiths had to do, and what ultimately spun off into an industry on its own. Another would be to modify something close. With the show and tell of last week push came to shove and I have been haunting E-Bay. A brand new offering turned up 2 days ago. Some place in the Pacific rim where Chinese is the language A set of taps and dies made of High speed steel and the tap threads ground from the solid was offered, so I bit and bought. If they have followed previous pattern I can diamond lap the tap to size and solve that problem. I can also use the required size tools to make a master form ( miniature lead screw and nut) before I try the lapping in case that fails. I'll know in about 10 days.

Early in all of this I gave up on the idea of simply buying replacement ZKK firepin/cocking piece assemblies. Which was the first solution. The fire pin and cocking piece in the pictures is from my early ZKK 602 which has the peep in bridge.

Another thing I do with these is fit the cocking cams of bolt and cocking piece to minimum tolerance. The bolt handle doesn't jump the spread at firing. These are all custom fitting one to one items and it requires these installations to be done with tooling to keep installation cost down.

I do not anticipate getting involved in the paper work for shipping out of country. Our govt. would prefer this be done using brokers.

I will post again - up or down- on how the re-tooling the tools operation completed.

There it is, the only thing that has kept me from buying multiple 550's.....resolved in spectacular fashion.

Keep us updated!