CZ 457 PRS Build

Match day was a blast, I had a ton of fun. I don't know what my score was yet, but I can tell you that I didn't win :p My custom bolt knob wasn't an issue like I was concerned it might be, it ran just fine. Build wise, zero issues chambering, extracting and ejecting, flawless performance. Goes to show concerns about tight chambers in repeaters may be slightly overblown, or speaks to my smithin' skills, you decide. I'm certainly feeling a certain satisfaction that not many can relate to. I didn't just bolt some components together and call it a rifle, I made steel chips fly and crafted this rifle to the fullest extent myself.

I added all 4 fore end weights and found that still didn't move the balance point far enough forward, weights close to the receiver have little effect on the balance. I did a quick and dirty external weight with a chunk of steel I had lying around, that made the balance good enough. Add it to my ever expanding machining project list to make the weight pretty at some point, but it's not a priority job. I might cut it in half so the two external weights can be mounted on either side of the stock right at the end of the fore stock for maximum balance effect, that'd be done when I get to making it pretty. Works for now so other jobs take precedence.

It was a very, very windy day so I'm glad we only shot to 100 yards, and it would have been a waste for me to use the Lapua Long Range. Jerry is coaching me like I'm a contender for first place when I'm just starting out, hehe. I have some learning and practice to do before the ammo starts holding me back. Maybe one day, but for now I'm happy shooting the SK HV. After the match I went to my range which was nearby for some more practice and took the pics I promised of the the finished build in it's element.

Awesome. Getting out there and shooting in some unconventional ("Modern") ways at little targets with the 22lr.
 
Couple ORPS matches to attend this month, one tomorrow, another in a couple weeks. I got out to the range today for some practice and to refine my scope settings. Last match I only had a 50y and 100y zero, since I was last at the range before registering for that match, this hurt my scores trying to guess holdovers at 25y and 75y stages. I put the Sightron SII 6-24x scope on since it can actually focus at 25y unlike the SIII. I had the time to test some ammo at 100y, gusty wind today so the horizontal from that shows up in the groups. I didn't shoot any expensive ammo, just the economical grades. Acceptable performance from 3/4 types, SK Semi-Auto confirmed to suck in this rifle. I was also getting my 64 w/IBI barrel sighted in with a new-to-me Leupold silhouette scope and was testing naked barrel to see what ammo I could use for silhouette. In my 64 rifle, the SK Semi-Auto meets the performance needs for me in silhouette, and the SK HV Match sucked. The opposite of my PRS CZ.

While this isn't a 5 year long peer reviewed study with 5000 groups shot to determine the exact difference in group averages to the 0.0000000001% between the two rifles with these ammo options, the testing is sufficient to determine there is indeed a significant difference in ammo performance from one rifle to the next with these two varieties of SK. I'm not naming anyone specific, since there are people on other forums who are not members here that promulgate such narratives, but the assertion that a good barrel simply needs good ammo to produce good results is untenable and so full of holes that it only stays afloat by the immense amount of hot air blown into it to displace the surge of water sinking it. Naturally, one cannot expect low quality cartridges to produce good results aside from the occasional random act of accuracy, garbage in, garbage out, after all. Quality cartridges are a prerequisite for good results, this goes without saying. One must then find the correct pairing of said quality ammo with their individual barrel for good results to be forthcoming. Should the ammo not suit the barrel, the results WILL be poor, the quality of the cartridges notwithstanding. This isn't even debatable. It is the fact of .22LR rifle shooting. Anyone is welcome to attempt to prove me wrong on this, but be forewarned, you will only prove me correct in your pursuit of doing so.









My CZ had up to 4.5" of vertical with the SK Semi-Auto, while the 64 was much tighter. I'm seeing that the barrel on my CZ is quite sensitive, I'm definitely going to have to work on mitigating the barrel vibrations. Perhaps I could attempt shimming the barrel at the end of the forestock with a pressure pad as an interim solution until I come up with a muzzle device for it. I purchased a nice set of bags, after today's practice session the pump pillow is huge plus IMO and I look forward to an improvement over my previous match score, which was around 300. They gave me a 0 on one stage for some reason, even though I did 60-70% hits there. No matter, I'd only have been middle of the pack with my actual score. I did some other "shooting" while at the range, please enjoy some rifle pR0n.







I don't have any other rifle build plans for this year, though I do have some further customizations and enhancements in the works for this build. I will post about them as I complete them in the coming weeks/months.
 
Your work on the CZ 457 is remarkable. Please keep updating with match results.

the assertion that a good barrel simply needs good ammo to produce good results is untenable and so full of holes that it only stays afloat by the immense amount of hot air blown into it to displace the surge of water sinking it. Naturally, one cannot expect low quality cartridges to produce good results aside from the occasional random act of accuracy, garbage in, garbage out, after all. Quality cartridges are a prerequisite for good results, this goes without saying. One must then find the correct pairing of said quality ammo with their individual barrel for good results to be forthcoming. Should the ammo not suit the barrel, the results WILL be poor, the quality of the cartridges notwithstanding. This isn't even debatable.
Good on you for championing the idea that, when it comes to accuracy performance, what matters most is matching the make or brand of ammo with the barrel. While a lot of guys might say that ammo quality and performance varies by lot and that good ammo shoots well across good barrels, it's amazing to see someone saying it's not so.

The results with the different ammos in the two rifles shown above prove the point and it shouldn't be debatable.
 
Absolutely love this thread and all the information in it! Please keep this going.

Quick note on the front weight on the chassis. It looks like the weight is sitting low enough to get in a way of any accessories you would put at the front part of the rail. I had that issue with mine DYI weights, and I had to redo the weights on both sides to sit higher
 
Your work on the CZ 457 is remarkable. Please keep updating with match results.


Good on you for championing the idea that, when it comes to accuracy performance, what matters most is matching the make or brand of ammo with the barrel. While a lot of guys might say that ammo quality and performance varies by lot and that good ammo shoots well across good barrels, it's amazing to see someone saying it's not so.

The results with the different ammos in the two rifles shown above prove the point and it shouldn't be debatable.
Thank you for your input.
Absolutely love this thread and all the information in it! Please keep this going.

Quick note on the front weight on the chassis. It looks like the weight is sitting low enough to get in a way of any accessories you would put at the front part of the rail. I had that issue with mine DYI weights, and I had to redo the weights on both sides to sit higher

Yeah like I mentioned in the previous page it was a quick and dirty job done just days before the first match. It works for now until I'm able to finish a proper weight setup, which I am working on. It took 10 hours of machine time to split the stock material to make the weights, for some perspective on what it takes to do these jobs. I really need to get a band saw...

2nd match reflection. I faced a much more challenging course of fire compared to the first match, given that I scored about the same this time on the hard course, I suppose that reflects at least some improvement. The targets were much smaller, setups more challenging, tight times, and very "swingy" targets when hit. Waiting for them to settle to shoot again resulted in time outs and incomplete stages. There is a very steep learning curve to this discipline, all the research and advice is great to get one off to a good start, but there is no substitute for diving in and experiencing what it's all about. In the heat of a match, you see where your strengths and weaknesses are, where your practice paid off, and things you didn't even realize you should practice. I had situations thrown at me that I was fully unprepared for, and it showed in my score on those stages. I also don't have anywhere to get my 75y zero, guessing holdover again and on smaller targets this did not go well. It's going to take me time to build all the skills this sport demands. Being able to build a rifle and shoot well off a bench in calm weather doesn't translate into being a PRS champion, lol ;) Now I just gotta tell work that I have to leave early every Tuesday so I can go to my home range's practice evenings :ROFLMAO:

So yeah, I'm loving this. It brings together my passion for building rifles, machining, rimfire shooting, and is pushing me to develop my skills in a way that sitting on a bench never could. I still have that curiosity to learn what really makes a rimfire accurate, though this is going to take a back seat for this more enjoyable pursuit. How many days one can spend at the range, shooting a brick of ammo, wondering "is this the tuner setting? No. This one? No. How about this one? No" and walk away with nothing to show for it, go back to the drawing board and figure out what to try next to get a rifle shooting, it wears thin over time. When that bench magic finally happens, it can be very satisfying for sure, though the path there isn't easy and usually isn't quick, at least in most of my experiences. I could easily spend a year or two with my two recent builds to get them producing something noteworthy from a benchrest perspective, if they're even capable of it inherently. They're both good for their respective disciplines, so some killer bench results would just be a bonus at this point.
 
Does your range Not allow setting up temp-targets at any distance so you can get data? I guess if they're a busy range that may happen. The range I shoot at is usually 'empty' when I go ( I'm retired ) so I can do what I want except for weekends.
 
I'll ask the range manager when I see him at the match this weekend, I've never seen anyone do that. Fortunately my range is not busy with people, even on the weekends when I'm able to go. We've had the CFO crawling up our butt recently so I'm not sure setting up a target without a berm directly behind it would be OK.
 
Do you find using ammo marked Semi Auto by the manufacturer yields good results usually in a bolt gun. Done just as a marketing ploy or is is the velocity a little higher? Just read your match experience and now you’ve been bitten by the bug. It’s habit forming. Usually the COF is available before the match so you can see what you’ll be facing on game day. Next step on the ladder is CRPS which is much more difficult
 
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SK Semi Auto is a faster ammo than other SK rifle ammo. It's factory-rated in a 660mm barrel at 1132 fps (345 m/s) -- it that has any real significance as there will be lot-to-lot, even box-to-box, variation in average MV. The price is sometimes an indicator of its value and place in an ammo variety hierarchy. All SK varieties should be considered entry level match/target ammo.
 
Our range just had a CFO visit and we need the berm 'raised'. Needs a certain 'angle of the face' to be acceptable, as well as height. It's about 20-ft high, built of 'stone-free' soil in a triangular mound about 50-yds wide and every 4-5 years it 'collapses' a bit. It costs about $5-10K (don't have a current quote yet) to have 'new' soil added and lifted to the top. The total range distance is 175 yds with 'marked' areas for target stands at 25, 50, 100, and the 175 at the berm. There are NOT 'backing berms' at each of those distances and this has been acceptable for 'many years'. The range is in an area of Crown land with NO residences behind the berm for 'miles and miles', which may contribute to the acceptance.
 
PS - RE SK ammo, I tested some SK-RM thru my VMTR last summer and got ES of 10-20 fps from various groups of shots. The speed went from 1180's to ca 1100's, at ca 26+ * on a Sunny and dry Summer day. (I don' t record Humidity, not that fussy) Test was using a Magnetospeed Sporter.
 
Do you find using ammo marked Semi Auto by the manufacturer yields good results usually in a bolt gun. Done just as a marketing ploy or is is the velocity a little higher? Just read your match experience and now you’ve been bitten by the bug. It’s habit forming. Usually the COF is available before the match so you can see what you’ll be facing on game day. Next step on the ladder is CRPS which is much more difficult
Why are you putting on a two-faced act coming in my thread acting like you didn't just spew repugnant filth about me? Nothing repulses me more than a disingenuous snake.
 
In Appropriate Behaviour/Action/Content 2 Points
The name is Chrissssss. Ill post wherever and whenever I please. At least I reply without using profanity or derogatory comments Myke. Careful or youll receive what Im assuming is your favourite colour again. Expected response time is 11.00-01.00. Noticed your shooting much lower grade ammo now than the R50 from before under the alias and the fake 1/4" target. Expect this will be removed like the last one.
 
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Why buy a bag? There'll be 20 there you can borrow as you shoot the stage.

Ammo choice really isn't that critical. Smallest target is going to be what, 3"?
3”?

1/4” at 40-60 yds where I shoot.

1” or 1-1/2” at 100 yds is something we see too.
 
3”?

1/4” at 40-60 yds where I shoot.

1” or 1-1/2” at 100 yds is something we see too.
for CRPS or benchrest?

None of our targets are close to that small - are they just lobbing softballs in the Maritimes?

I THINK we did a KYL rack at 25y last year, I can't think of anything smaller.
 
for CRPS or benchrest?

None of our targets are close to that small - are they just lobbing softballs in the Maritimes?

I THINK we did a KYL rack at 25y last year, I can't think of anything smaller.
For our rimfire PRS matches. After the Feb match the league posted a picture of a 100 yd target beside a penny. They were the same size. The caption read: “This 100 yd target broke many hearts.” 🤣
 
Went to my 3rd match today back at the same venue as my 1st one. We had some light spitting rain though it wasn't much of a bother, windy again but not as extreme as the last time. Seems to always be windy around here lately. I leaped up the ladder and took 4th place with a score of 410. I made it out to my range's practice night earlier in the week and was feeling good going into the match. My squad started off on the two 100y stages and I blew it, 50 points each. Talk about being deflated right off the bat. I had a number of shots I know I broke clean but missed nonetheless. This venue doesn't put out a 100y zero board at the start so at this point I'm questioning my scope settings wondering if I'm way off because I zeroed in windy conditions at practice that don't align with the conditions of today. I did good on the 75y stage then cleaned the 25y KYL stage and also cleaned the 50/75y multi-yard stage to finish. That was satisfying. OK, so I was good out to 75y but something is going wrong past that.

I went to my range after the match to see what's going on. I started on the bottom left bull, a little low and right but not bad, shouldn't have caused me too much grief. I shot more groups and this tells the story. From a solid bench rest, SK HV is giving me around 2" groups on average. With 1.5" targets to shoot at the match, this will cause misses through no fault of my own. Now add the wobble from shooting off a barricade, it's making sense. The vertical aligns with expected MV variation for this grade of ammo so the rifle likes it well enough but with the random dispersion and odd fliers, the more I shoot this ammo the more I realize it's not a very good lot at all. I guess I got to the point that I've outgrown the SK HV faster than I expected. Practice ammo. I've got enough Lapua Long Range to last me a few more matches but I can't get that lot anymore. I'll need to figure out another ammo to use, whether I order some more LR and hope for the best or test out the RWS I have, I've got some time to get that sorted.



I want to give a thanks to Eugene for a few tips he gave me, that's helped me along. Now that I'm getting more comfortable with the sport and familiar with my rifle and how it handles, I'm thinking about what would be the best setup for me with it. A bipod seems like a good addition, there are a number of stages where it would smooth out setup transitions. Bags are workable, given that's what I used and cleaned the stage, but a bipod is attached and moves with the rifle, one less thing to think about and possibly mess up. My temporary weight has the rifle balance "workable", but I need to get it just right. That's my current project and now is a good time to segue into some machining adventures :) Machining is one of those things where one finds themselves often making something to make something that's needed to make the original project. It's an Inception-like rabbit hole, lol.

I've got most of the work done on my external weight set, I just need to make an internal grooving cutter to make a quick detach swivel stud hole and then do the surface finishing work so that the weights look good too. To make the special tool, I'm now building an upgraded tool rest for my bench grinder. I need to slot the platen for a mitre gauge, good luck finding a T-slot cutter of the required dimensions. So, I made one! Drill bits and taps tend to break over the course of one's machining career, but rather than throw them out, the savvy machinist saves them. They're good tool steel, after all. They can be recycled into specialty cutters for one-off jobs where a purchase is either not possible or financially practical. With a carbide end-mill I machined the cutter to the required dimensions.



Did a quick test in a piece of scrap, the cutter cuts well.



The slots cut are perfect for the mitre gauge, success! :D



I've already made several of the brackets for the grinder rest, now I've got the T-slot cutter needed for the platen so I can go ahead and machine up the platen next. Then I'll be done milling work for awhile and I've got a backlog of lathe work to do. I have 3 in-process projects that need both mill and lathe work, I just wasn't going to bounce back and forth between the setups. All mill work done first, then lathe work. I should have my weights done before the next match if all goes well.
 
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