BRNO ZG 47 and ZKK-600 differences

[Homer]

G'Day Fella's,

This post relates to a couple of older made centrefire rifles that I own, that most of you may may not be familiar with.
I don't want to try and sound like I'm some Guru on any of these rifles but I do enjoy working on and using these Brno, and other post WWII centrefire rifles.

Both the Brno ZG 47 and the Brno ZKK-600, were designed for .30-06 size and length cartridges, and were made in an era, before business Bean Counters, had total control over manufacturing costs.
This is not allways a great thing, as there is No Aluminium or Plastic components, which means, if it's not Wood ...... its Carbon Steel (which adds weight), but I have no issues with that.
The ZG 47, came about, from and after the Brno, Model 21 and 22 rifles, and the ZKK 600 series (600, 601 & 602), replaced the ZG 47.
They are both basic modern variations, of the Mauser 1898 (with Control Round Feeding and a Non-Rotating Extractor, Standing Ejector, etc), rifle but unlike the Mauser of 1898, they were made specifically, as sporting/hunting rifles.
The thing I enjoy about this era of sporting rifles, is how they have utilised the best features of the Mauser 98, but they then got adventuress, and incorporated their own ideas and designs that they wanted to promote.

Here is the ZG 47

DSCN3769.JPG (584.83 KiB) Viewed 12353 times

Here is the ZKK-600 (minus recoil pad ....... work in progress).
As you can see, both rifles have straight bolt handles.

DSCN1625 (1).JPG (920.64 KiB) Viewed 12353 times

As you might be able to see on both rifles, both the receiver ring and bridge, are what they call double square, with the factory inclusion, of 19mm (3/4" ish) dovetails on both.

Seeing that the ZG 47 came along first, I'll post a few images of it initially, and let the images do the talking.
Here you can see the right hand side of the action, including the straight bolt handle, bolt shroud mounted-rotating safety (in the Fire position), elongated trigger guard, curved trigger, and Mauser type inside the trigger guard / Obendorf style floor plate release, etc.

DSCN3770.JPG (1.24 MiB) Viewed 12340 times

DSCN3775.JPG (1.4 MiB) Viewed 12180 times

Here is an elevated view of the top right hand side, giving a better view of the intricately detailed and machined bolt shroud, dovetails, rotating safety etc.

DSCN3771.JPG (1.11 MiB) Viewed 12340 times

Here is the left hand side of the action, you can see the Mauser type non-rotating extractor, and bolt stop/release/standing ejector housing, etc.

DSCN3773.JPG (795.32 KiB) Viewed 12340 times

That'll do for the moment.

D'oh!
Homer

[marksman]

"That'll do for the moment."
you tease Homer

l have always had a brno fetish owning zkk 600, 601, 602 models but l have never had the spare kanga for a zg47
to me the zg47 is the perfect tarzan type rifle that l like

thanks for posting

[Homer]

G'Day Fella's,

Appologies Marksman, been a bit busy of late mate.

When I took possession of this ZG 47 rifle, I was a little apprehensive about it, as it was a Sight Unseen purchase.
There was one issue inside the barrel but nothing I can't live with, and the purchase price, took this into consideration.
Apart from that, the rifle came to me in what appeared to be, and as I refer to as, "Unmolested Condition".
This was confirmed to me, when I removed the barreled action, from the stock.
Please see the following image, of what was found hiding, once the stock was removed.

DSCN3752 (2).JPG (1.33 MiB) Viewed 12160 times

and ..... Luckily, only two small spots of surface rust were also hiding, among all the dirt, saw dust and Pine Needles.

DSCN3753.JPG (1.62 MiB) Viewed 12160 times

Please also see, the adjustable trigger (adjustable for Sear Engagment and Trigger Pull Weight), of this rifle.

DSCN3759.JPG (1.23 MiB) Viewed 12160 times

.

Here also, is a close up image of the ZG 47 stamp and, Proof Marks and "56" date of manufacture (that being-1956) stamp marks, along with some of the dirt etc.

DSCN3754.JPG (1.84 MiB) Viewed 12160 times

And of the roll marks ............

DSCN3767.JPG (1.11 MiB) Viewed 12148 times

and serial number on the barrel.
(Also, please note how the dovetails on the receiver ring, are machined, all the way through).

DSCN3768_LI (2).jpg (2.78 MiB) Viewed 12148 times

Whilst I had the rifle apart, I degreased and cleaned all the trigger components. While I was at it, I honed and polished both the sear engagement surfaces.
I then adjusted the sear engagement and reduced the trigger pull weight, to a nice, creep free but Safe, 2 1/2 pounds (or, 1.2 Kg ish).
I also degreased and cleaned the rest of the barreled action, inside and out (including the bolt lug abutment cavity/recess), I then wiped all the metal work over with Sweets, Gun Oil (not to be confused with the same company's,"7.62 Bore Solvent").
I have been using this Australian made gun oil, for decades, as a rust preventative on all my own, and customers firearms.

Next I pulled the bolt apart, and degreased and cleaned all these parts.
As can be seen from the following image, this (apart from the bolt shroud, safety and straight bolt handle), is all classic, Mauser 98.

DSCN3760.JPG (1.26 MiB) Viewed 12160 times

After this was completed, I oiled the internal bolt components (with Break Free - CLP Oil) and reassembled the bolt.
FYI, one thing that most people neglect to do, is to place a small amount of grease on the rear faces, of the Bolt Locking Lugs.
These two (in this instance) critical surfaces, seem to be the most neglected area of most firearms.
This is unfortunate, as they are subjected to so much force, and also, they are so critical to a firearm's accuracy.

Prior to re-assembleing the rifle, I also degreased and cleaned the trigger guard and floor plate.
I then oiled it up with Sweets, Gun Oil and placed a drop of Break Free oil, on the floor plate release latch mechanism.

DSCN3774.JPG (1008.68 KiB) Viewed 12160 times

That'll have to do for the moment, as there is no rest for the wicked, and the jobs around here, won't do things themselves.

Avagreatweekendeh!
Homer

[cracker]

loverly rifles mate.
very jelous !
ZG 47 in .404 jeffery would be a dream

[Homer]

loverly rifles mate.
very jelous !
ZG 47 in .404 jeffery would be a dream

Mmmmmmmmmmmmmmmmmmmmmmmmmmmm .404 Jeff Donuts!

Avagreatweekendeh!
Homer

[Homer]

G'Day Fella's,

Just for a bit of a comparison, I've lined up a few bolts from various older rifles.

FYI, please note the location of the Standing Ejector's cut out, in both the of the Brno's, BSA , Win M70 Pre 64 and "Classic", Ruger and Kimber 84 bolt face.
From Left to Right- Rem 700, Brno ZKK-600, ZG47, BSA Royal, Win Pre-64 M70, M70 Classic, Ruger M77 MkII, Kimber 84.

L to R- Rem 700, Brno ZKK-600, ZG47, BSA Royal, Win Pre-64 M70, M70 Classic, Ruger M77 MkII, Kimber 84.JPG (701.89 KiB) Viewed 11986 times

L to R- Rem 700, Brno ZKK-600, ZG47, BSA Royal, Win Pre-64 M70, M70 Classic, Ruger M77 MkII, Kimber 84 (2).JPG (1.62 MiB) Viewed 11986 times

Top to Bot-Rem 700, Brno ZKK-600, ZG47, BSA Royal, Win Pre-64 M70, M70 Classic, Ruger M77 MkII, Kimber 84.JPG (1.77 MiB) Viewed 11986 times

I hope you can see from the above images, the evolution from the original Mauser (basically the same as ther ZG47), how these rifle designs varied, and then for a number of years became a non-viable option.
On the Left hand side, we have a Remington 700 bolt, which when you look at lack of large parts, and the work required to make them, shows why the others generally became too expensive to manufacture.
Mind you, in recent years, we see Mauser again producing new model 98 rifles again but this time, at a premium price, and then we have Ruger M77 (and more recently the new Kimber's), which have been plodding along, making their version of the 98 Mauser, all along ...........

Avagreatweekendeh!
Homer

[Homer]

G'Day Fella's,

Here are some additional images, of this same Brno ZG47.

This image shows a better view of how the receiver ring dovetails, have been machined continuously thru.

DSCN3792.JPG (1.4 MiB) Viewed 12049 times

This image shows both the receiver bridge dovetail, scope mount recoil abuttment recess, and Mauser type bolt stop/release,etc.

DSCN3793.JPG (974.11 KiB) Viewed 12049 times

These next two images, show the safety in it's forward applied/SAFE position.
The ZG47's safety, retracts the firing pin, backwards off the sear and also locks the bolt handle from being opened (deliberately or accidently), when it has been applied, in the forward or Safe position.
This makes applying the safety, a little bit difficult, as you are actually compressing the firing pin spring an additional, small amount, to achieve this.

DSCN3794.JPG (1.16 MiB) Viewed 12049 times

DSCN3796 (2).JPG (1013.45 KiB) Viewed 12049 times

Here are some images of the rear and front iron sights.
The rear sight is adjustable for windage, via two opposing screws (the RHS one, is visible here), in its dovetail, machined into its integral barrel mounted sight base.

DSCN3811.JPG (308.49 KiB) Viewed 12049 times

Here is the removable front sight blade.
By depressing the checkered cylinderical button, in front of the sight blade, the front sight blade can be slid forward, out of it's barrel banded, sight mount.

DSCN3812.JPG (180.75 KiB) Viewed 12049 times

All of this additional machining, took time and effort, and this added cost to the purchase price, of these particular rifles.
This, and the popularity and better reliability of modern optical sights (rifle scopes), eventually became an unesseccary cost, and most other manufacturers. Some dropped these as options, and some others went out of business.
As a Machinist myself, it is all these additional options and effort, that I appreciate and enjoy having available to me.

Thats about it for this particular rifle, I'll make a start on the Brno ZKK-600 when I get a chance.

D'oh!
Homer

[Homer]

G'Day Fella',s

So some time in the 1960's (late in 1965?), Brno had a rethink on how they built their centrefire rifles.
To the best of my knowledge, their previous Model 21, 22 and the ZG47, were all machined from bar stock (a piece of steel bar, cut to length and then completley machined, to the end product).
With the ZKK-600 series, they completley changed their approach on How To make a rifle action, by utilising the Lost Wax or Investment Cast process (please see the below link), to make their actions, and component parts.
In most cases, these components were then machined, to their final finish.
FYI, Sturm Ruger & Co also utilise the Investment Cast method, to produce so many of their firearm component parts.
FYI, I just located this series of back-to-back Youtube video's, on how Ruger does this, and other manufacturing processes.
https://www.youtube.com/watch?v=ZBYw1CT2JiU

Here is an image of the RHS of the complete rifle.

DSCN3810.JPG (700.52 KiB) Viewed 12036 times

Here is the top surface of the receiver ring of my Brno, ZKK-600 (1970 production), showing it's "as cast" external finish.

DSCN3799.JPG (731 KiB) Viewed 12037 times

Here you can see the LHS of the "as cast" reciever ring, high lighting the blind dovetail, the Proof Mark stamp, along with the year of production stamp 70 (for 1970)

DSCN1623.JPG (798.79 KiB) Viewed 12037 times

Here is an image of the LHS of the action itself, high lighting the double square, receiver and bridge, dovetails, scope mount recoil abuttment recess, and it's unique, pop up ghost ring peep sight (in it's Up position), etc

DSCN3798.JPG (734.35 KiB) Viewed 12037 times

Below the stock line, the metal work of the ZKK-600 action itself, apart from the area to the rear of the recoil lug being radiused, is basically the same as the ZG47, from the front of the action to the rear of the box magazine.
Beyond the rear of the magazine box, there are some major fundermental differences, as the action's tang area of the action and the trigger system, are totally different and the trigger system, being of it's own unique design.
Here are some images of the action's tang and trigger areas and mechanism, including highlighted Sear surfaces.

DSCN3817_LI.jpg (2 MiB) Viewed 12009 times

Underneath view of tang and trigger mechanism..

DSCN3818 (2).JPG (1.01 MiB) Viewed 12009 times

Here you can see that the actual trigger lever (the bit your trgger finger jumps on), is mounted in the trigger guard section of the bottom metal. And see how the top extension / tounge enters the trigger machanism recess, located on the underside of the action.

DSCN3820.JPG (1.49 MiB) Viewed 12009 times

In addition to the standard trigger, the ZKK-600 series came with a extra single set trigger.
Here's a view of it laying just forward, of where it would be positioned, if fitted.

DSCN3822.JPG (808.52 KiB) Viewed 12009 times

On the inside, there are some other major differences a well, with the standing ejector and bolt stop, being in seperate locations and appear to have been borrowed, from other sporting rifles.
The bolt stop appears similar to a Winchester Model 70, including it's release latch, where as the standing ejector seems to be a variation on both the BSA and Winchester bolt action designs (also see previous images, of bolt heads/faces).
In the following images, you can see the internal location of the standing ejector (just Left of centre), bolt stop (in Left bolt raceway) and its release latch (only partially on the far LHS), the safety lever (far RHS and in the rear, or FIRE position), plus the deployed ghost ring, peep sight.

DSCN3800.JPG (603.62 KiB) Viewed 12021 times

and outside

DSCN1629.JPG (838.31 KiB) Viewed 12021 times

FYI, I found the following details, regarding the history of Brno/CZ on line. I'm not sure how correct it is but if it is, it is fairly comprehensive;
https://www.rimfirecentral.com/forums/s ... hp?t=97155

D'oh!
Homer

[Homer]

G'Day Fella's,

Further to this thread, FYI here are some additional images etc.

This image again shows the rear view of the action, back into the inside of it.
BR = Bolt Release, BS = Bolt Stop and SE = Standing Ejector.
In addition to this, you can see the safety lever, on the RHS.

DSCN3827_LI.jpg (1.83 MiB) Viewed 12007 times

Here you can see the rear RHS of the action.
This includes the safety, in it's rear or FIRE position (which is Back to Front from all other safety levers), and the Peep Sight, in it's retracted position, and it's release button, with-in the receiver bridge.

DSCN3825.JPG (1.69 MiB) Viewed 12007 times

Here we have the front sight, at home in the banded front base (note the lack of checkering on the top of the cylinderical retention button, unlike on the ZG47).

DSCN3805.JPG (490.51 KiB) Viewed 12007 times

This time, you can see that the spring loaded, cylinderical retention button has been depressed and the replacable sight blade, has been partially removed.
There are multiple reason for this is. You can put taller or shorter front sights blades in, to adjust the Point Of Impact (POI).
You can put in larger more visible or coloured front sights, etc, etc.

DSCN3807.JPG (385.02 KiB) Viewed 12007 times

This image shows an underside view of the actions recoil lug. Apart from the area to the rear of the recoil lug (the area between the recoil lug and the magazine well), is round/radiused in cross section, rather than flat on the ZG47. Apart from this, this area of the rifle's action, is basically the same as ZG47.

DSCN3830.JPG (1014.07 KiB) Viewed 12007 times

Here you can see what the forend screw, screws into. Lets call it the Nut ...... for lack of a better description.
This has the ability to slide length wise in it's mount (which is in the underside, of the rear sight mount).
Whilst the ZG47 forend screw Nut is of a different design (see previous and earlier image), it basically functions the same.

DSCN3824.JPG (758.35 KiB) Viewed 12007 times

Speaking of which, here is the windage adjustable (with a hammer and soft drift), folding rear sight in it's Up position .....

DSCN3808.JPG (379.87 KiB) Viewed 12007 times

and in it's folded, or Down position. In this position, it allows the pop up peep sight to be used, without any visual interference.

DSCN3809.JPG (278.6 KiB) Viewed 12007 times

Thats about it I think .............

Avagreatweekendeh!
Homer

[Homer]

But Wait ......... theres more.

I forgot to mention, that the ZKK-600 series of rifles, has another little usefull device, available to its owner/user in the field.
You can see the yellow pointer, high lighting the small square button, with checkered end, on the LHS of the bolt shroud.

DSCN1630 (1).JPG (1.55 MiB) Viewed 11999 times

When this button is activated, by pressing it in (along with some other coordinated actions), it allows the rifles firing pin system, to be easily unthreaded and removed from the rifle bolt (in the field, at home, etc).

DSCN1631.JPG (890.5 KiB) Viewed 11999 times

Winchester also have a similar system present (but a different design and in a different location ....... and not as well done), on their M70 bolt action rifles.
So like the floor plate release on the 600 series of rifles, it appears Brno had a good look at a M70 rifle, when they were designing this particular rifle.

It's these little things, that are just not present on so many other production rifles (because of their cost/need), and the way that Brno have gone about doing it, that I enjoy and appreciate on both of these Brno rifle designs.

So, I think thats about it, I hope you enjoyed the read?

Avagreatweekendeh!
Homer