Did a little rebuild on the CZ-527

JTPinTX

Custom Call Maker
Some of you guys probably followed my thread a couple years ago where I replaced the old shot out barrel on my 527 with a new factory take off. The original was a 12 twist 223, and the new one was a 9 twist 223. I did the swap myself including a very basic true up of the receiver face. Original barrel shot pretty good but the new one has been crazy accurate. I could dig up that old thread if anyone was interested.

When I swapped barrels I left the new one at factory length even though my original had been cut to 18" and threaded for a can. However, after using it a while after the swap I really liked the handling of the previous shorter length.

I have also been wanting to put the rifle in a good composite stock for years. But all you CZ guys know there is pretty much one option, it has the Varmint barrel channel, and my rifle is a sporter. I finally decided I didn't care if it had a big barrel channel gap or not though, I was going to put it in that B&C stock.

Another factor was I do lots of night hunting off a tripod and have really been wanting to get an ARCA plate mounted on the bottom of this rifle like the rest of my rifles. I have used it several times at night but having to use a Reaper Grip is a PITA after you get used to an ARCA mount. The shape of the factory wood stock is not conducive at all to adding an ARCA plate.

So I bit the bullet and ordered the B&C stock in brown spiderweb and the 3" Henderson Precision ARCA plate. Also I added a DIP picatinny rail to it for making it easier to swap back and forth from thermal (QD mount) to daylight scope.

I tore the rifle down, pulled the barrel, chopped it to 18 and re-threaded for the suppressor QD mount. When the stock got here I went ahead and bedded the action and bottom metal into the stock even though it does have a nice aluminum bedding block molded into it. Only issues I ran across there was the bottom metal had a little interference where the angled gusset on the back of the mag well was hitting the aluminum web in the stock. I had to relieve the aluminum a bit with the dremel to get it to seat all the way in. Other than that, good fit. Once that was done I drilled and tapped the stock 1/4"x20 for a couple solid bolts to install the ACRA plate and countersunk, then epoxied backing nuts for that on the inside of the barrel channel.

Very happy with how it all turned out. Just like a little mini precision rifle. Very nice feel and shoots great off the bench.

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First picture is what the barrel gap looks like with a sporter barrel in a varmint stock. Actually doesn't look quite as big in person as it does in the pic. Maybe I'll get around to filling it up some, maybe not. Not hugely concerned about it. It is a killing rifle not a show piece.

Next pic is it up next to my 243. End of suppressors are lined up the exact same spot in the floorboard of the truck. Shows you just how compact this thing is. 243 is a short action R-700 cut to 21", sporter weight bbl in an AG Composites Alpine stock. So it isn't a big rifle, and the CZ is tiny next to it. I think B&C did a pretty good job of matching the scale of the stock to the little mini barreled action.

Last pic is how it shoots with loads that weren't even tuned for this barrel, in a 20 mph north wind. Shoots better than that on a nice day. Pretty sweet when a varmint bullet and and a serious controlled expansion bullet shoot to basically the same POI. Nice for when you are calling coyotes and run across pigs. Keep an extra mag with them in the stock pack.

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Great post...I have always been a big fan of 1:8 but I have found that the twist ALONG with the length of barrel dictates the accuracy of the gun. So when I use 16 or 18in it is a 1:8 but you have shown that there are so many more variables that go into the accuracy of a gun.

You've got a tack driver there and a pretty one to boot...
 
Thanks Mo. It is a 1:9, so right there in the range of what you are talking for a short barrel. Something that short I don't plan to ever run anything much over a 65 SGK or 62 HPBT, just because of velocity. And when I say I cut it to 18", I mean both receiver and muzzle threads included. The exposed part of the barrel is 16 3/4". It is short no doubt. Handles like a dream in the truck. Should be a really nice little night gun.

I am about to start testing with the 53 VMAX. If it will shoot good, and I bet it will since I have not seen anything yet this barrel won't shoot, then my goal is to shoot the 53 VMAX for coyotes and the 55 TTSX as backup in case we stumble across pigs. Should be a great combo.

The suppressor is an old Specwar 556K, it is short as well at only 6.2". But sounds really good on there. Daylight scope is an original run (Gen 1?) Vortex Viper 4-12 with BDC. I always thought those very first Vortex scopes were some of the clearest ones they ever made that weren't part of the Razor/PST line.

Just overall a nice, balanced sweet handling and shooting little rifle.
 
That looks great! Is that the rifle you shot the barrel out of target practicing behind your shop? I remember you talking about one you'd shot out in one of my threads. I think it was about shooting offhand.
 
Yes it is, great memory on your part. My daughter did her fair share of shooting that original barrel out as well, but most of it was me.
 
Pretty impressed with that BC stock, especially considering the price. Had a couple of little minor fitting issues, easy to fix. Which is actually pretty common with any stock in my experience. Barreled action part went in and fit perfect. Both minor issues I had were on the bottom metal. First was I had to file the aluminum crossbar right behind the mag well a bit to clear the angled gusset on the back of the mag well. I described that above.

Second issue I found later. I had been doing testing with my 3 round mag and it had been feeding fine, no issues. My 5 round mag though sits just a hair lower in the mag well than the 3. When I went to use it, it would not feed the bolt was slipping over the top of the case head of the rounds in the mag by just a hair. It was bumping them but would not quite push them forward. So I had to pull the bottom metal and grind down the bottom of the rear pillar just a bit and rebed the bottom metal. That let everything sit up in there between 1/32" and 1/16" deeper, raising the back of the mag enough the bolt could catch the rounds. This rifle has had that issue before when I bedded the original wood stock with steel pillars in it. So probably unique to my gun and not really a B&C thing. Simple fix at any rate.

But it is a light, rigid little stock with a good feel and proportioned very well for the mini Mauser action. For sure made to fit that rifle and not just a standard design that was modded to fit.
 
Thanks Everyone!

Put the Thermion XQ50 on it this afternoon and got it zeroed with 50 Blitzkings. May have to go take it for a drive tonight and bust some coyotes.
 
good gawd, I love those little CZ's. My Brother picked up a new 527 sporter in 204 Ruger a few months back. Got it for like $700 I think. But I just got a really nice one in 223.
 
I wouldn't mind owning that rifle. Maybe I would have went with a 22 in. barrel. But it's yours and it turned out great. I hope it bring you good memories.
 
Factory length on the American sporter is only 21.6” I think. And it is not a bad length at all. Really nice without a can. But with a can kind of long for me. I prefer the short super compact size. Only about 3.5” difference though.
 
I have that same exact stock on a savage 110 223 cal, I cut the barrel down to 16 inches. It shoots good groups and is very easy to carry out hunting. I have shot a pile of coyotes with the 223 shooting 40 gr. V-Max out of 26 inch barrel, a lot of people have said bad things about the 40 gr vmax being an effective coyote round but I have confidence in it. however with the rifle I cut the barrel down to 16 inches there was a dramatic difference on the effects of coyotes being hit with the 223 vmax. i dont know if it was a recipe in velocity but i was seeing the same results i have read so many complain about using vmaxs on coyotes out of that 16 inch barrel, very few dropped right where I hit them. even on well placed shots they were running a ways. I gave it a very good chance and shot somewhere around 50 coyotes with it until my confidence in hunting with it diminished.

Im just a hunter so I dont know any science of ballistics, just an opinion on what i have seen thru my scope. I just spent the last couple months shooting them with a 308 165 gr fusion while my 22-250 was being worked on. even that large round I use on deer was giving me similar results hitting coyotes and them not going straight down. Im back to the 22-250 shooting 50 gr vmax and it was a fresh relief seeing the results of them being hit with that projectile this last hunt and remembering all the others i shot with this round in the past. My only issue with shooting the 50 gr. Vmax is that it does not shoot well through grass or weeds. What i have seen with heavier rounds without the polymer tip is that if a coyote is standing in weeds and you can only see its head and the top of its back back you can still aim low and that heavier round will most of the time chew through the weeds and pass through that coyote.
 
Originally Posted By: Infidel 762I have that same exact stock on a savage 110 223 cal, I cut the barrel down to 16 inches. It shoots good groups and is very easy to carry out hunting. I have shot a pile of coyotes with the 223 shooting 40 gr. V-Max out of 26 inch barrel, a lot of people have said bad things about the 40 gr vmax being an effective coyote round but I have confidence in it. however with the rifle I cut the barrel down to 16 inches there was a dramatic difference on the effects of coyotes being hit with the 223 vmax. i dont know if it was a recipe in velocity but i was seeing the same results i have read so many complain about using vmaxs on coyotes out of that 16 inch barrel, very few dropped right where I hit them. even on well placed shots they were running a ways. I gave it a very good chance and shot somewhere around 50 coyotes with it until my confidence in hunting with it diminished.

Im just a hunter so I dont know any science of ballistics, just an opinion on what i have seen thru my scope. I just spent the last couple months shooting them with a 308 165 gr fusion while my 22-250 was being worked on. even that large round I use on deer was giving me similar results hitting coyotes and them not going straight down. Im back to the 22-250 shooting 50 gr vmax and it was a fresh relief seeing the results of them being hit with that projectile this last hunt and remembering all the others i shot with this round in the past. My only issue with shooting the 50 gr. Vmax is that it does not shoot well through grass or weeds. What i have seen with heavier rounds without the polymer tip is that if a coyote is standing in weeds and you can only see its head and the top of its back back you can still aim low and that heavier round will most of the time chew through the weeds and pass through that coyote.

I'm not real big on using V-Max. For the past 3 or 4 seasons I've been using 55 grain Softpoints. Two seasons ago I shot 63 animals that Winter. Mostly coyotes and a few badgers and bobcats. I had 0 get up and run off. Only had to shoot a few coyotes twice. And they were so messed up they weren't running off very fast, if at all. I have only lost two in my time shooting those bullets to the best of my recollection. They definitely don't stop inside them on a broadside shot and leave about a golf ball sized exit most of the time but it drops them. Hit them right behind the shoulder and they're gonna drop and stay dropped every time.
 
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Well, lots to unpack in those last 2 posts.

So much influences bullet performance. Velocity, twist rate (bullet rpm), I think sometimes even the depth of rifling and maybe the smoothness of it can have different effects on the bullet and how fast it comes apart. Just several reasons that people can have widely varying results with the same bullet, and also why I love studying ballistics so much.

For most of its life this CZ has had an 18” barrel. The original had a 12 twist, this one is a 9. But honestly it has always put coyotes down pretty good no matter what. Better than my 7 twist, 14.5” AR for sure. But I do reload and have always pushed speed pretty hard. Even so never really had any blow ups that I know about.

The 50 VMAX I had some left I needed to shoot, they are gone I shot them up. I have swapped to the 50 Blitzking. Some folks say they are a bit soft and kind of splashy as well but I have not had any trouble with them yet. I will say I am more particular about my shots when I use the 223 instead of the 243. 243 puts coyotes down as hard as anything I have ever shot, period. 87 VMAX has a great mix of fast opening energy dump, and still a plenty of penetration. Plus a good BC, it carries that energy out well. It works so good I think sometimes it makes me a sloppy shooter. But that little 223, it shoots so good, so smooth. I just have a lot of confidence on shot placement and that is a big key as well. But I won’t push distance with it like I do the 243.

Personally I feel a 55 Sierra soft point is one of the best coyote bullets ever made. And lots of old time coyote killers agree with me on that. The 50 is probably as good in the 223 as the 55 is in the 22-250. I’m not saying the 223 is as good as a 22-250, just that the 50 matches the 223 like a 55 matches the 22-250, if that makes sense. 22-250 still has at least a 75-100 yard or more range advantage over the 223.
 
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That is a good point. I have definitely noticed the different performance in bullets based on barrel length so I can vouch for that. I think it was about 4 years ago I switched from shooting a Ruger M77 MarkII Compact with a 1:12 twist,16 1/2" barrel to a Remington 700 ADL which has a 1:12,24" barrel. The Sierra Blitzkings were among some of my favorite fur saving bullets for coyotes in the Ruger. They would blow big holes in coyotes if you hit the "edges" but every bullet will do that so that was no surprise there. In the 24" barrel it leaves huge exit wounds if you hit them in a soft part of their body. For example hitting them broadside in the neck. It leaves softball sized exit wounds shooting them through the 24" barrel. They don't go anywhere but they're nasty lookin.

Admittedly I didn't have very many test subjects before I decided to leave those bullets for the 16 1/2" barrel. I suppose it's just the added velocity that makes the difference. That's all I figured it could be. I shot a feral cat in the chest once with a Blitzking out of the Ruger. It didn't even exit out of the back. The cat just made a sloshing noise because everything inside of it was liquid.

One thing that both rifles have in common is they're both very fur friendly when shooting a Hornady 52gr. BTHP. If fur prices are up and I'm targeting bobcats that's my bullet of choice in either rifle.

I don't recall ever killing any coyotes with 55 grain Softpoints out of the Ruger. I don't know why. I thought hollowpoints and plastic tipped bullets looked cooler I guess. There for about 10 years I shot different bullets all the time. I was on a quest to try them all on coyotes.
 
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