CZ 527, re-barrel, cartridge options?

JTPinTX

JTPinTX

Custom Call Maker
I have a CZ-527 that the barrel is about shot out on. It started life as a high volume practice rifle for me, but the last few years it has been cut down and modified as my daughters primary rifle. She loves it and shoots if for everything, jackrabbits, coyotes, deer, whatever. She is recoil and noise sensitive, but it wears a Specwar 556K suppressor which really helps. She loves this rifle and shoots it a lot.

The original barrel is a 12 twist, but a couple years ago I picked up a brand new factory takeoff 9 twist from James Calhoon. The original plan was just to swap barrels when the throat was gone (checking headspace of course) and roll on. The new 9 twist would let her shoot some heavier bullets (like the 65 SGK) for deer, making it much better for her. Once this deer season is over I plan to do the swap, sometime in the next 2-6 months.

One of our members on here that lives 30 miles away from me has agreed to help me with the swap, he has a lathe and has re-barreled several of his own rifles with wildcat cartridges.

Here comes the question part. Simple thing is just to keep it a 223 and roll with it. Second option is punching the chamber out to something larger.

223 AI is the first thing that comes to mind. I could buy/rent a reamer for that. I know that to be done right the barrel should actually be set back a thread to get everything correct. OAL should still work just fine with the factory magazine, but I am not sure if the 223 AI would feed good out of the factory magazines due to minimum body taper?

I know there are going to be folks who say just buy a new barrel blank and go from there. But I already have this one and my experience is that factory CZ barrels generally shoot plenty good enough for what I am needing out of this rifle. It isn't going to be much of a target rifle, it is a field shooting, practicing, and killing rifle.

I would like to hear thoughts and opinions on this project.
 
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IF.......your friend has the tools to do the swap and the labor is free or inexpensive, you already have the new barrel, I say give it a try. The 223AI is a great little round. As far as feeding, I did it to a Remington and it wasn't a reliable feed but it wasn't feeding from a mag. Maybe some others can help with this.
 
See if you can borrow/buy a couple of pieces of sized 223AI brass, make a dummy round and see if they will feed. They don't have to feed all the way into the chamber(they won't fit) but they will go in far enough to see if they will feed out of the mag. Just don't get over zealous and jam one into the chamber.
 
Sure- go for it.

Several years ago I bought a new ER Shaw .223 barrel for my Savage 112 but never put it on because the factory .223 barrel was still shooting great. But after I acquired a couple more .223 rifles I decided to have the Shaw barrel opened up to .223 AI and put that on the gun. Let me tell you- I never regretted it. A jillion ground squirrels and a couple thousand prairie dogs, some as far as 700 yards, have fallen to the gun.

Brass life is great, accuracy is super, and since I single load feeding from a magazine is non issue.

My .223 rifles dont get shot much anymore. Dont really have a reason to.
 
Originally Posted By: AWSSee if you can borrow/buy a couple of pieces of sized 223AI brass, make a dummy round and see if they will feed. They don't have to feed all the way into the chamber(they won't fit) but they will go in far enough to see if they will feed out of the mag. Just don't get over zealous and jam one into the chamber.

Excellent idea. I have plenty of time on this project to make sure I am headed down the right path. Being a hunting rifle for my daughter, it really does need to feed correctly, that is my main concern.

If anyone has a couple pieces of old 223 AI brass laying around...
 
I have a 223AI built on a SA Rem 700 and I'm using a HS Prec detachable mag system, it feeds perfectly fine and even though yours is a CZ setup, I'd sure think it would feed fine, too.

As for doing a 223 AI over a standard 223, like I said I have a 223AI and it shoots crazy good, BUT, to do all over again, I wouldn't do an Ack Imp on the 223 case. For me, there just isn't that much increase in velocity to make the extra effort and different dies worth it, over a standard 223. If you want more case capacity, IMO, there are much better options.

Since you are considering having it re-chambered anyway and it sounds like you are looking for something with better performance than a standard 223, I'd look into having it re-chambered into a 22 Nosler. It will still use the same 223 bolt face but it'll have a pretty healthy increase in performance over either of the 223 versions you're considering. You probably would have to use a different magazine though, maybe one for the 6.5 Grendal, either that or just single feed them.
 
What will the AI give you (how much more) as in velocity that the standard cant? My little CZ is a stardard .223 and its screamin pretty good with a 53gr Vmax
Im not trying to discourage you, just look at it from a realistic approach.
 
Pressure being equal, and that's the important part to remember when comparing the standard 223 to the 223AI, the AI version gains about 75fps.

Now, you'll hear all kinds of things like there's 150-200fps gain in velocity and you can certainly make a AI version run that much faster than the standard 223, but, I can promise you they aren't running at comparable pressures.
 
Well Steve, to be honest I am not really sure. Internet data is all over the place on that one. I think, in something like a 24" barrel maybe 75-150 FPS? However that little CZ has a pretty short barrel to begin with, and as you know I have the current one chopped to 18" for her since I have the suppressor on it. Because it handles so good for her at that length, I imagine this next one will be chopped pretty similar. That might influence the results even more. In a barrel that short I wonder if it might just be a 50-100 FPS improvement. I really have no idea though.

Then again, part of the reason for the AI is for brass life and trimming, not just speed That isn't really a big deal though if it is going to give me feeding trouble.
 
Looks like I was posting at the same time as B23. Gaining just 75 FPS or so, makes me really sit and think hard about it. In reality there probably is no practical reason to do it. Except sometimes the rifle loony bug strikes and makes you do it anyways.

But this is exactly why I posted the thread. To try and get some good information to base my decision off of.
 
Testing with a couple of pieces of AI brass is a dang good idea but being single stack and CRF I'm betting it isn't a problem.

I'd AI it just to try something different. I've yet to hear anyone regret the move.

I doubt that the magazine will accommodate any of the super long VLD stuff but since it's a hunting rifle the nine twist will at least let you shoot heavier bullets and the extra AI horse power sure won't hurt with those.
My 9 twist 527 Carbine shoots factory 70gr Barnes TTSX really well.

Good luck what ever path you choose.
 
I forget about the short barrel part of her rifle. In that regard I think going AI is a good thing as long as it feeds really well.
My thoughts of it feeding are spot on with RePete. I think the Mauser action with its control round feeding will be a plus.
Another thought, give James Calhoun a call and see if he knows about any feeding hick-ups with the AI and the 527.
Shoot Jeff, youve got me all excited about your procject now! Lol
 
I actually have a CZ527 in 223AI. Feeding from Factory mags is not quite as smooth as non AI, but still completely reliable. Mine is still a 12 twist, so I am limited to fairly short bullets. It has a real taste for the 50gr Vmax, and I am pushing them at 3510fps from an 18" tube with a Silencerco Harvester.

The switch to Ackley is completely worth it in brass life and ease of prep alone. For me, the added speed is a bonus, and with a short barrel I figure I have gained what I would have lost with a standard .223.
 
Originally Posted By: liliysdad
The switch to Ackley is completely worth it in brass life and ease of prep alone. For me, the added speed is a bonus, and with a short barrel I figure I have gained what I would have lost with a standard .223.

With my 24" Hart barrel .223 AI I get around 3800 FPS with the 50 grain and 4000 FPS with the 40 grainers. I have gotten more speed than that with both bullet weights but did not see the need for it so backed it back down a bit.
 
Originally Posted By: liliysdadI actually have a CZ527 in 223AI. Feeding from Factory mags is not quite as smooth as non AI, but still completely reliable. Mine is still a 12 twist, so I am limited to fairly short bullets. It has a real taste for the 50gr Vmax, and I am pushing them at 3510fps from an 18" tube with a Silencerco Harvester.

The switch to Ackley is completely worth it in brass life and ease of prep alone. For me, the added speed is a bonus, and with a short barrel I figure I have gained what I would have lost with a standard .223.

That is where I am at with this deal. Less brass prep and maybe get back the FPS I lost by chopping the barrel, or a little more. My first can was a Harvester. I shot it on the CZ some, but it was pretty long. Going to the Specwar 556K saved me 3" of OAL on the rifle. The Specwar is some louder than the Harvester, but not enough to really matter.

Thanks for the input, really good to hear from someone who has actually done this chambering in a CZ.
 
Who Cares about equal pressures, that talk is nonsense!

I have owned a flock of both custom 223's and AI's, and I believe this case is as accurate as the 22 PPC which I had 4 of.

I shoot Remington 700's with the 223 AI. It is best to have the firing pin bushed by Greg Tannel of Gre Tan rifles.

The AI is super accurate, fast. The extra powder capacity will sure help with a 64g Winchester or 65g Sierra for deer.

Use thick cup primers, cci 41, 7 1/2, cci br4. CCI 450's opened up the groups with these lighter bullets. Varget with cci 450 with the 65's would be a good marriage.

N133 with the 50's
N135 with the 55g
N135 or N140 with the 64-65g
you will be dumbfounded at the accuracy and speed.

I run the 55's at 3650 out of a 25", 14twist with zero freebore. I would throat it out a tad for the 64g Winchester.

Mag length in the CZ is problematic, shorter freebore the better and I hope that he has a PTG uni throater.

I started shooting the 223 AI in 1987, and have not been without one ever since, and I prefer a 26" for dog towns and a 24" for coyotes.

40g at 4100+
50g at 3800+
55g at 3550-3650

saves a ton of barrel life compared to a 22/250. I use a reamer that has zero freebore, .252 neck, IMI, Lake City, and Lapua brass ONLY!

We named the 223 AI, Mighty Mouse!

The CZ should do well in a single stack magazine.
 
Thanks for your input, Keith. You sure say it better than anyone else can here. And because you likely have had more dealings with the .223 AI than anyone else has on this site (with the possible exception of Steve Timm) your words and advise are golden.
 
Originally Posted By: ackleymanWho Cares about equal pressures, that talk is nonsense!

No, not nonsense at all and that is just ignorant to say that. You can't hot rod one and not the other and then pretend there is something magical you're doing that gains you this huge velocity increase.

The only reason you are getting those velocities you're claiming is because you are loading them to excessive pressure and you could do the same thing with a standard 223 and be within 75fps.

I'm sure you all remember Catshooter. I didn't always agree with him but he was a pretty sharp cat, no pun intended, and he too didn't think the 223AI was worth doing for only 75fps gain over a standard 223.

Like I said, I have one, it shoots VERY well but that doesn't mean it wouldn't have shot just as well being a standard 223 and for the minimal gain you get, I don't think it's worth it.
 
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