CZ527-.223 Rem group issues

[epc308]

A friend got a brand new rifle from CZ bc his original was a clunker. Meanwhile, he bought a Remington, didn’t want both, sold the CZ to me at a great price. It came with the walnut sporter stock that was difficult to shoot from the bags. In the sale he tossed in the CZ laminate stock. I switched stocks and the bag issues went away, to be replaced with scope issues, so I thought. That turned out to be ring issues. Switched from Warne to Talley and that problem went away. I’ve shot multiple loads of mine, several proven by friends in their CZs and other rifles. I will get groups of 2 touching, 2 more touching, and a loner. See the pictures. 3 other shooters of known, good skills have shot this rifle and get the same results. Any idea what’s up?

 

[Adam in WI]

Is your stock bedded properly?


Also, shoot me a message if you're interested in parting with the factory walnut. I might be looking for a replacement for my Tupperware.

 

[biggun2869]

I just know that mine shoots a lot better than that, I'd have to look for the load, but it is a nonfactor. You need to work up the load for YOUR gun. Everyone else's particular loads mean nothing. Not even as a starting load as you need to start lower.
I've read your intro so according to that you know what you're doing but what you have posted does not grasp that. I drink too, maybe this is influenced??

 

[Mark W]

I also have a walnut and a laminated stock. The laminated is better, but still not what I would call an "easy" gun to shoot off of bags.

Mine shoots groups like that with factory ammo. I would check the action screw torque and a do proper load work up.

 

[Yamess191]

My left handed factory CZ 527 in 204 shoots 3-5 shots touching with factory hornady 32 grain v max ammo, but that is one of two guns in the safe that will shoot factory ammo well. I think I got lucky. The rest of the rifles in the safe won’t group much better than 2-3 MOA at a 100 yards with factory loaded ammo.
I have learned over the years a lot goes into getting groups in and under 1/2” at 100 yards. Though once in a while you get lucky out of the box!

 

[watercam]

FWIW I have a CZ 527 that was chambered for the .204 cartridge originally. I measured the throat free bore and it was long - over 0.100". I took it to a gunsmith and he turned the barrel shoulder back a bit as well as the breach face. Then used a chamber reamer with a more conventional free bore and that allowed me to have some kind of control over seating depth.
The gun has become my Highpower Mid-range rifle in .223 and is more accurate than I am for sure.

 

[Yamess191]

FWIW I have a CZ 527 that was chambered for the .204 cartridge originally. I measured the throat free bore and it was long - over 0.100". I took it to a gunsmith and he turned the barrel shoulder back a bit as well as the breach face. Then used a chamber reamer with a more conventional free bore and that allowed me to have some kind of control over seating depth.
The gun has become my Highpower Mid-range rifle in .223 and is more accurate than I am for sure.

That’s interesting. I haven’t measured the chamber free bore on that rifle yet because it shoots so well with factory ammo I don’t really care to reload for it unless I have too ( I have About 12 more rifles I have to find a load for). But that is good info for epc308.
And possibly a short cut for epc308 that I did with a AR that had a lot of free bore is try the longest bullet the twist rate will stabilize and that will eliminate some of the jump the bullet has to do to get to the lands, and maybe eliminate having to send it to a smith? It tightened up my groups when I did it...

 

[epc308]

I just know that mine shoots a lot better than that, I'd have to look for the load, but it is a nonfactor. You need to work up the load for YOUR gun. Everyone else's particular loads mean nothing. Not even as a starting load as you need to start lower.
I've read your intro so according to that you know what you're doing but what you have posted does not grasp that. I drink too, maybe this is influenced??

I realize every gun is unique and it’s up to me to find the combo that will prove up. Two brothers I know each have the same rifle, both shoot multiple combos well, all shoot uniform type groups. If it was only group size but showed potential, it would be a matter of fine tuning a given load.
My point was that all combinations I have tried in mine gave the 2-2-1 type of group.
I use the Hornady type measuring tool for case head to ogive length(s) to figure throat length dimensions. All combinations fit in and cycle through the magazine, so it isn’t an extra long throat. I can seat at, or any distance back from, the lands with anything of the 55-69g bullets I’ve tried so far. None of the rounds look strange with bullets either hanging out of or pushed way back in the case.
As for drinking, this rifle hasn’t taken me there, at least not yet.

 

[chkunz]

You are not seeing the big picture by shooting five shot groups with this gun.

Shoot a 20 or 30 shot group and you will see what is going on. This gun is shooting a BIG group and you can not get the true picture with five shot groups. A big group is not a good thing but knowing what it is, is much better than chasing two shots touching in a five shot group with a an inaccurate gun.

 

[epc308]

Is your stock bedded properly?


Also, shoot me a message if you're interested in parting with the factory walnut. I might be looking for a replacement for my Tupperware.

Bedded properly? Whatever that means to any given person you ask, but that’s the next step. This one had some compound at the recoil lug area. I have been told, for what that’s worth, that CZ put some in that area from the factory in the laminate stocks. Yes/no, anyone know?
Is there supposed to be one, two, or no steel sleeves from the factory for this laminate stock?
Thinking more on the bedding issue, this laminate came from the original rifle. Manufacturing tolerances being what they are, it’s possible there is enough variation from the original to this barreled action to cause issues. Next step is the flex shaft Dremel and get rid of the bedding, machine a front and rear sleeve to sit a few thousandths shy of receiver and bottom metal, then torque it together, receiver firmly seated against the wood. It worked that way for how many million rifles so far, at least as a starting point.
Oh, and load up all the combinations for the third time.
Third time is the charm, isn’t it?

 

[Dub]

Bedded properly? Whatever that means to any given person you ask, but that’s the next step. This one had some compound at the recoil lug area. I have been told, for what that’s worth, that CZ put some in that area from the factory in the laminate stocks. Yes/no, anyone know?
Is there supposed to be one, two, or no steel sleeves from the factory for this laminate stock?
Thinking more on the bedding issue, this laminate came from the original rifle. Manufacturing tolerances being what they are, it’s possible there is enough variation from the original to this barreled action to cause issues. Next step is the flex shaft Dremel and get rid of the bedding, machine a front and rear sleeve to sit a few thousandths shy of receiver and bottom metal, then torque it together, receiver firmly seated against the wood. It worked that way for how many million rifles so far, at least as a starting point.
Oh, and load up all the combinations for the third time.
Third time is the charm, isn’t it?

this seems to be more of a defensive response rather than trying to learn from what has been shared.

 

[epc308]

You are not seeing the big picture by shooting five shot groups with this gun.

Shoot a 20 or 30 shot group and you will see what is going on. This gun is shooting a BIG group and you can not get the true picture with five shot groups. A big group is not a good thing but knowing what it is, is much better than chasing two shots touching in a five shot group with a an inaccurate gun.

The picture shows two separate groups, not one large one. 5 shot groups have always allowed me to at least see potential for the past 40 years. I don’t know anyone that does things differently, at least in the beginning.I’m not going to make up 20-30 of any given load before then. That seems counter productive.

this seems to be more of a defensive response rather than trying to learn from what has been shared.

this seems to be more of a defensive response rather than trying to learn from what has been shared.

Not sure how you got that impression. I’m basically thinking out loud.

 

[Dub]

my apologies then. I mis interpreted your response

 

[epc308]

my apologies then. I mis interpreted your response

Apology accepted. No harm, no foul.
What I didn’t mention in my response was/is the cost and scarcity of components these days. I guess I figured it was a given for all of us.

 

[Bill K]

I would check at least two things, Bedding and also the crown on your rifle.

CZ does put some bedding compound in the slot for the recoil lug, it is on the soft side, as least that is my opinion. You can rectify that by doing a good bedding job, if needed, on your lami stock.

 

[epc308]

I would check at least two things, Bedding and also the crown on your rifle.

CZ does put some bedding compound in the slot for the recoil lug, it is on the soft side, as least that is my opinion. You can rectify that by doing a good bedding job, if needed, on your lami stock.

The bedding compound is now all gone, and there was more than only in the slot. The receiver sits flat front to back, no rocking, with new spacers at both action screw locations.
I forgot to mention the crown in my initial post. It showed an odd build up at the muzzle after the second shooting session, looking almost like lube build up from cast bullets. It stood proud of the muzzle too, not the typical flat powder star. The build up was more pronounced to one direction. I looked close with a magnifier after a thorough cleaning, and the crown didn't look so great. The Q-tip test left some fuzz. I took things apart, dialed it in on the lathe, and made a 45 degree cut to cleanup the ends of the lands. The next shooting session left nothing but a concentric powder star, with none of the former build up.

 

[th82457]

I have had several CZ 527's in ,221, .222 ,204 & .223. Currently have one in .17 Hornet & .20 Vartarg. The only one that did not improve with re-bedding was a .204 Varmint with the synthetic stock with aluminum bedding block. It shot so well in stock form that I never touched it. Anyway, I would suggest a careful bedding job with devcon or whichever compound you prefer & float the barrel. Also with the bullet weights you are shooting - is this a 1:9 twist barrel or 1:12 ? I know my older .223 American was 1:12. I believe the Varmint barrel models have always been 1:9 - but I could be wrong on that. Between what you found at the crown & a good bedding job, you should see the double grouping go away.

Good Luck !

 

[Ramblerman]

Let us know how she shoots

 

[K22]

I have several 223 Rem's with twists ranging from 12" - 9" - 8" but I don't have a CZ.

Powders that I've used that have been successful in all are H335, Benchmark, Varget, and H 4895.

Bullets that I've used with excellent results are the Nosler 50 and 55 grain in the 12" twist and the 55 in the 9" and 8" twists. Also used the Hornady 60 Vmax with 8" twist with excellent results.

In my faster twist rifles, I discovered that the lower end of the velocity range works best with 55 and 60 grain bullets.

There are a few shooting condition factors that could explain the spread of those groups. How fast (heating the barrel) are you shooting those groups? What are the wind / mirage conditions? How stable is the rest you are using? Are you returning the rifle to the same position on the rest after each shot? Is the rifle level on the rest? How many groups are you trying to shoot in one range session - i.e. shooter fatigue.

An 1" to 1 1/2" groups are not that unusual for factory rifle barrels unfortunately. I've been able to get most of mine to shoot under an 1" but it some cases it took some load development effort, bedding, stock replacements and / or free floating barrels. Also, I have some rifles that prefer a longer jump, some as much as .50" from the lands.

Assuming you're using a suitable powder for the 223 Rem, over years of shooting I found that the single most important factor affecting group size is the bullet. You may have to try some different bullets to get more consistent groups.

Cleaning is also important - not letting the carbon and copper fouling to build up.

 

[epc308]

I have had several CZ 527's in ,221, .222 ,204 & .223. Currently have one in .17 Hornet & .20 Vartarg. The only one that did not improve with re-bedding was a .204 Varmint with the synthetic stock with aluminum bedding block. It shot so well in stock form that I never touched it. Anyway, I would suggest a careful bedding job with devcon or whichever compound you prefer & float the barrel. Also with the bullet weights you are shooting - is this a 1:9 twist barrel or 1:12 ? I know my older .223 American was 1:12. I believe the Varmint barrel models have always been 1:9 - but I could be wrong on that. Between what you found at the crown & a good bedding job, you should see the double grouping go away.

Good Luck !

Thanks for the suggestions. The barrel has easily 1/8” of clearance, so it’s well floated. It’s the varmint contour with 1/9” twist, so should shoot anything other than the heaviest bullets. I’m going to try shooting without bedding it first. If 40+ years in manufacturing taught me anything, it’s to only change one thing at a time. If nothing else, I will get another day at the range for more trials.