Evolution of a CZ 550 375 H&H

[benchracer]

I bought this rifle back in 2010, with intent to take it to Africa. Haven't made it to Africa just yet, but I have put in a fair bit of trigger time behind this rifle. As can be seen in the photo, original equipment was a "hogback" style stock. Despite its disadvantages for use with optics, I was fond of the stock, generally finding it pleasant to handle and shoot (except from the bench). I took it afield in pursuit of whitetail deer in the Kentucky woods the first season I had it. Using reduced lead bullet loads, I bagged my first ever whitetail deer (an immature doe), dropping her where she stood. It was a clean, instantaneous kill that made good table fare.

The scope I originally mounted was a steel-tubed Meopta Artemis 2000, 1.5-6x42, with a 4B FFP reticle. It was and is a marvelous, rugged optic at a reasonable price. The glass quality was superb, delivering clear image quality even in the dark of night. It's only shortcoming was eye relief that was on the short side. With a hard hold on the rifle, it was still manageable, but attention needed to be paid to avoid scope bite. I wish this scope were still in production. Updated with just a little more eye relief and an illuminated center, a scope like this would be just about the perfect instrument for a safari rifle.

Prior to purchase, I did not fully understand the difference between the true magnum length, double square bridge CZ 550 action and most other 375's built on more conventional actions. I welcomed the additional size and weight of the rifle when shooting full power loads. I found it to be a well balanced rifle and actually enjoyed carrying it afield. The 3.8" magazine of the CZ 550 (vs the 3.6" magazine found in most other rifles chambered for 375 H&H) caught my attention early on. After taking some measurements and giving it some thought, I realized there was a lot of ballistic potential being left on the table by book load data that limited OAL to 3.6". I began to experiment with longer OAL's, slower powders, and heavier bullets...

 

[benchracer]

Left to right, I worked with the Barnes 250 TTSX, Hornady 300 BTSP, Sierra 300 Gameking, Cutting Edge 300 MTH, and Sierra 350 Matchking. On the far right, is an example of a Sierra 350 Matchking loaded to an OAL of 4.040". I had good results with the Barnes and CFE223, but was more interested in the results I was getting with combinations like the 300's and RL-17 and the Sierra 350 Matchking with RL-22.

None of those experiments were practical for safari purposes. They were an exploration of what was possible with some homework and the right combination of components, in a true magnum length action. It was during these experiments, though, that I began to discover some of the issues with this rifle that needed correction...

 

[benchracer]

While I was doing load development, I saw consistent signs that the rifle "wanted" to shoot. It had a tendency to print two shots close together, while throwing the third shot further away. Here are some pretty typical examples:

 

[benchracer]

Results like this caused me to inspect the fit between the barrel and stock more closely. Admittedly, that is something I should have done right out of the box when the rifle was new and had corrected earlier in the process. I wasted a good bit of time and reloading components before I realized the problems I was seeing on target were more than just the loose nut behind the trigger (shooter error). Upon close inspection, I noticed the barrel channel of the stock was indeed making contact with the barrel. A trip to the gunsmith for some bedding work was in order.

Nathan Foster, of Ballistic Studies, had this to say about the CZ 550 and its known bedding issues:

To fully exploit the accuracy potential of the Brno / CZ rifle, it should be properly bedded using a steel based epoxy resin (such as our MatchGrade bedding compound) which can cope with heavy magnums. I am no great fan of the second recoil lug system which can be found on the barrel of many of these rifles. This second lug does help prevent the stock from swelling at the magazine well and splitting under recoil in its basic factory rifle form but is in no way on par with cross bolts (or simple cross screws) and steel based epoxy bedding which achieves strength while enhancing accuracy potential. Many of these rifles also feature a third screw within the forend, pulling the barrel down and locking it in place. A locked barrel can be very accurate (e.g target rifles with ‘blocked’ barrels) however in a wood stocked rifle, the POI can shift over time due to stock warping. This method of anchoring the barrel can place a good deal of stress on the entire system. It should be no surprise to anyone with some measure of gunsmithing or engineering aptitude that such a system can both work exceptionally well but also fail miserably depending on the fit of each individual barrel within each forend. Unfortunately, die-hard fans of the CZ rifle tend to voice their enthusiasm for the big rifles so loudly that those who own poorly shooting rifles as a result of such ills often blame themselves when their cannon does not live up to the legends.

The CZ rifle works very well with a free floated barrel. The wood stock is not overly strong but with cross screws or bolts (or a stronger aftermarket stock) combined with steel based epoxy bedding, accuracy can be very good. As a contrast to this, those who wish to attempt to bed the CZ with its barrel lug in place may be in for a world of hurt. When bedding all the way from the action to the leaf sights, the bedding area is so long that one can easily flex the forend during the cure, resulting in a stressed bedding job. It is also very hard to guarantee the alignment of a fixed lug (at the action) and a floating lug (many CZ rifles utilize a floating secondary lug), both at the same time. A compromise is to create a more easily aligned secondary lug by cutting a small piece of steel and to temporarily glue this to the barrel lug recess during bedding, after which the glue bond breaks, leaving the lug correctly aligned in the epoxy bedding. But again, it is very difficult to bed over such a great distance without inducing some level of stress within the system. Two step bedding (receiver bedding followed by barrel channel as a separate operation) is generally disastrous as it is near impossible to have two separate areas of bedding without one placing stress on the other. It is for these reasons that rifle barrels are generally fully free floated rather than fully bedded. It is also equally difficult to prevent a wood stock forend from warping over time. Even with bedding, a forend may eventually develop some stress which is hard to eliminate over such a great length.

The gunsmith who did the bedding work for me did a fine job. Positive results were immediately apparent on target:

Consistent with Nathan Foster's writings, though, the bedding work was very difficult and frustrating, even to a Master Gunsmith. His only half-joking words to me when I visited his shop to pick up my rifle were: "F**k you! I am NEVER going to do something like that again!"

 

[benchracer]

With the bedding sorted out, I removed the Meopta scope in favor of something more suited to the long range testing I wanted to do with some of the loads I was developing. This was where I discovered another (as it turns out) known issue with the CZ 550: The factory scope mounting surfaces were not true. With its low magnification and 30mm tube, the Meopta had enough adjustment to compensate. When I tried to install a more long range friendly scope, I ran out of vertical adjustment about 20 MOA below what I would have needed for even a 100 yard zero.

After further research on the matter, I decided that the best solution was to add a picatinny rail from Murphy Precision. Installation of the rail would require that the action be drilled and tapped, so another trip to the gunsmith would be in order.

I re-installed the Meopta scope and ordered the picatinny rail. It arrived promptly and I sat it aside for several years, not feeling the immediate need to take corrective action.

 

[benchracer]

With the passing of time, I thought more and more about installing a more optics friendly stock. The CZ 550 was available from the factory in a Kevlar stocked version. In retrospect, I decided, I would have been better off to go that route originally. The truth was, I just didn't know enough to even consider the question at the time of purchase. My mistake could still be corrected easily enough, if I felt that to be necessary. The same Kevlar stock could still be had from Bell & Carlson at a reasonable price.

Still, I didn't feel any particular sense of urgency to act. That thought sat in the back of my head, along with the thought to add a picatinny rail to address the scope mounting issues, for several years. Until...

 

[benchracer]

In the spring of 2020, CZ announced that the 550 Safari Magnum would be discontinued and the era of the affordable, Czech made Magnum Mauser was about to pass into history. Since I already owned one of these classic rifles, I was not directly affected. But, I decided that was the time to move forward with any of the improvements I was thinking of making, while aftermarket parts were still readily available.

I ordered the Bell & Carlson stock almost as soon as I read the news of the CZ 550's coming demise. With the Kevlar stock in hand, I gave some thought to my next moves. I decided it was time to go ahead with a makeover.

The new stock would resolve any potential bedding issues, free float the barrel, and unlock the full accuracy potential of the rifle. Having the action drilled and tapped for the installation of the picatinny rail would resolve optics alignment issues. While I was at it, I decided to have the metal finished with Cerakote, making my rifle into a rugged package that could absorb punishment in just about any field environment. Having admired the looks of recent production Winchester Model 70's finished with Tungsten Cerakote, I decided to go that route.

 

[fourfive8]

Yes, that is quite the evolution and journey!
Now to see some targets to compare with the bedded, wood stock version. Then some plans to take it to hunt Africa or Alaska…

I’m not so sure of the ‘smith’s evaluation of full length bedding inducing stress during the process, if done correctly? Any stress would be a result of the wood itself changing well after the fact, over time. But will agree, correctly bedding those and their cousins the BRNOs are a challenge! The gunsmith was probably used to bedding easy-peasy Rem 700s.

 

[benchracer]

With the known CZ 550 issues now resolved, I mounted a long range friendly optic and picked up where I had left off with my experiments, finally seeing them through to completion, and proving to my satisfaction that the 375 H&H is even more versatile when housed in a true magnum action. It remains relevant as an up close and personal rifle in close cover or when reaching out after big game in open country.

With the makeover and long distance experimentation completed, my thoughts turn back to the original purpose for purchasing this rifle: Africa.

Load development with 300 grain Swift A-Frames and a temp stable powder, loaded to sub-3.6" OAL and crimped for reliability will begin. Iron sights will be zeroed. A suitable optic for use in Africa will be mounted.

A new generation of LPVO's (Low Power Variable Optics) has come into existence. Though they appear mainly intended for tactical applications, they have a feature set that I believe may be a nearly perfect match to the .375 H&H in a traditional hunting environment: rugged construction, sufficient eye relief (3.5" to 4"), 1-6 or 1-8 magnification range, FFP, lighted reticles, and a reticle design that can function equally well in close quarters or at medium range. I plan to work with these to test their suitability, though the old Meopta will still be in play, at the very least as a backup optic.

I intend to practice diligently at smooth, fast gun handling and quick, accurate close quarters shooting. A meeting with an old Dagga Boy and some plains game is still in my plan. I just have some financial objectives to complete to clear the way. In the mean time, with the rifle sorted out, I will work on sorting out the shooter...

 

[fourfive8]

Sounds like a good plan! 3.5-4" eye relief is an excellent idea and relieves the shooter of worrying about that. With your mounting system, you can even get a little extra out of that eye relief and further help prevent any chance of getting hit. 1- 4, 5 or 6x modern variables are just right for your intended uses for that rifle.

 

[benchracer]

Yes, that is quite the evolution and journey!
Now to see some targets to compare with the bedded, wood stock version. Then some plans to take it to hunt Africa or Alaska…

I’m not so sure of the ‘smith’s evaluation of full length bedding inducing stress during the process, if done correctly? Any stress would be a result of the wood itself changing well after the fact, over time. But will agree, correctly bedding those and their cousins the BRNOs are a challenge! The gunsmith was probably used to bedding easy-peasy Rem 700s.

You are correct that the smith who did the bedding work was probably not accustomed to seeing a steady stream of CZ's or BRNO's, though he did excellent work.

I had good, solid loads developed while I still had the original stock installed. After switching to the Bell & Carlson, I stopped shooting at paper and began working with those loads on 12" x 12" steel targets at distances that are outside the subject matter of this forum. My ability to control this rifle from the bench or from the prone is still not perfectly consistent, but when my technique was on and my wind call was right, hits came with ease and without suspense.

In the aggregate, I am not sure that the change to a Kevlar stock yielded an increase in mechanical accuracy. The advantages of the Bell & Carlson stock involve a more optics-friendly design (aiding the shooter, not necessarily the rifle itself) and reliable, predictable accuracy. With the action torqued into the aluminum bedding block and the barrel free floated, I no longer have concerns about aging of the stock or changing conditions during travel causing unpredictable shifts in performance or point of impact, caused by warpage/expansion/contraction of the wood. Based on evidence on target, the bedding job was done correctly and was working properly. I just wasn't sure how long or how reliably it would remain that way. Given the ultimate purpose of the rifle, I felt a nod to reliability might be a wiser course.

As I shift back to preparation for hunting in Africa, I will be doing more load development that will result in targets for comparison. This time, though, components and loading techniques will prioritize reliability over pinpoint accuracy, so I am not sure what results will actually be seen on target. I will surely share them as I have them.

 

[CBH Australia]

I have one of these but the American Safari model. It's a different stock.
I did my own bedding job and in fact I took note of Nathan Fosters writing regarding this.

Actually I bedded a .458wm and later purchased a .375H&H switching stocks before selling the .458wm to recoup some costs.

I'm not into fiddly stuff but I do like to work on my own guns in my own time.

Interested in the results you get for accuracy in the Kevlar stock. I considered these but I wanted my Elephant gun to be a Blued /Timber rifle. (Safari rifle)

 

[Nhoro]

I have one of these but the American Safari model. It's a different stock.
I did my own bedding job and in fact I took note of Nathan Fosters writing regarding this.

Actually I bedded a .458wm and later purchased a .375H&H switching stocks before selling the .458wm to recoup some costs.

I'm not into fiddly stuff but I do like to work on my own guns in my own time.

Interested in the results you get for accuracy in the Kevlar stock. I considered these but I wanted my Elephant gun to be a Blued /Timber rifle. (Safari rifle)

I also bedded my CZ 550. It just needs some reading up and a little thought to create tolerances in the right places to avoid bending the barrel or action as you torque it down. My gun is more accurate than I am.

 

[Tokoloshe Safaris]

You have a fine rifle and it sounds like your really getting to know it well.

I would like to make a couple of comments. At this time you need no factory parts for your rifle. When you start investigating unless your luck is better than mine there are almost none available. I have had friends check all of the normal sources in the U.S.. Stock screws, most sight blades, the T-nut for the fore ends screws almost nothing is available. So far nothing is available in South Africa. I was able to get a couple of Bell and Carlson stocks in South Africa.

What I am saying if you have a chance to pick up any spare parts do it!

Your CZ will do everything that some factory rifles selling for ten to fifteen the price of your CZ and you will be just as proud when you take your first solid boss buffalo.

Cheers, Lon