Range Report: CZ527M (7.62x39)

[Netpackrat]

It's 1/2-28. I'd have preferred a larger diameter thread, but there was only so much meat there to begin with. My gunsmith friend mentioned that the barrel is not clocked quite correctly in the action, but I would likely have never noticed that on my own. I ordered a quick mount/flash hider for the suppressor I am getting. I think I mentioned earlier in the thread that I was not enamored of the high iron sights.... Forget that. Looks like they will be tall enough to use with the suppressor mounted, if the scope breaks.

Edit to add; looks like it didn't lose any barrel length based on the CZ specs page (18.5")... When I dropped it off, he thought he might have to shorten it slightly to get past the screw hole for the front sight base. I'm guessing that was far enough back, that the hole is still under the forward part of the base.

[Netpackrat]

The "thread protector" arrived today, along with the special socket from AAC, shim pack, and their special thread locking compound (aka "Rocksett"). The shim pack is normally only required for clocking the muzzle brake version of the quick mount properly, but I'm kind of picky about things being right, so I ordered it and I am glad that I did. Due to a slight counterbore at the back of the flash hider, it initially just barely bottomed on the front sight base instead of the shoulder, so I added a single .032" shim. This gave more than enough clearance, and just happened to clock the flash hider just about the way I wanted it. I used the .032" shim (thickest in the package) on the theory that it would be less apt to distort when torqued (20-30 ft-lb spec), which should minimize any tendency for misalignment, and also if I need to remove it for some reason, maximize the chance of being able to re-use the same shim.



As an unexpected bonus, the finish is a very good match for the rifle's bluing. I'm pretty happy with the way it looks, and I like it a lot more than the YHM quick mount that I have on another rifle, at least as much as I can say that without having a can to mount to either (the YHM flash hider on the other rifle will be replaced with an AAC as I get closer to taking delivery of the AAC can I bought).



Another unexpected bonus, is I had planned on tackling the misfeed issue I reported on earlier. I started hand cycling cartridges through it to see if it was hanging up high, or low, in which case adjusting the mag lips would hopefully do the trick, and to my surprise, it didn't do that anymore. I hand cycled several brands of ammo through it, and none of them hung up feeding into the chamber. One brand of ammo only (PRVI) would hang the second round of a full mag up below the feed lips, requiring a sharp jolt to raise it into position. I'm pretty sure that recoil would suffice for this purpose, so it might not even do that at the range.

Not sure if my friend specifically did anything to fix that... I'd mentioned it to him a few weeks before I actually dropped the rifle off, but he didn't say anything about it when I picked it up, and I didn't ask him to. Last summer when I had the misfeed problem, Google revealed that it's not uncommon for the 527 to do that, and apparently assembly practices can have an effect on it. So whether the result of an intentional fix, or just careful reassembly, it seems to be better now, which makes me very happy.

The other day I also found a nearly new condition Brownells' Latigo Sling in the safe that is cut for another gun that I'm not using it with anymore, so I am going to shorten that to fit the CZ, and save a little money over buying a new one. It's natural tan instead of the matte black that I was planning to get, but it should look and work just fine on this rifle.

[Netpackrat]

Made a quick trip to the range with this today, and fired a couple of 5 shot groups. Accuracy was unchanged after the threading and re-crown; Winchester soft points grouped at 1.5 inches, and Zombie Max still prints a 2 inch group at 100 yards. Forgot that the Redfield scope is marked in 1 moa increments instead of 1/4 moa, which caused me some confusion when I went to re-zero, but I was able to get it where I wanted it (3" high for a 200 yd zero) before I had to leave.

The new flash hider rings like a tuning fork with each shot; I have read this is typical of the Blackout flash hider and it shouldn't be evident with the can installed. I had a couple more failures to fire due to light primer strikes; This seems to be a common problem with the 527, and I will research getting a stronger firing pin spring.

[Darrell]

but I was able to get it where I wanted it (3" high for a 200 yd zero) before I had to leave.

Pardon me for asking, but isn't 3" high at 200 yds a little, um, optimistic for that caliber and carbine? Would that put you dead on at 300?

[Netpackrat]

3" high at 100 yards should put it close to zero at 200. I'll probably refine it later when I have more time.

[Flintlock Tom]

This thread, and Hickok45's video, are haunting me! I [strike]want[/strike] NEED this gun!

The kids can go without shoes for another year.

[Denis]

I finally got my Vortex Viper 2-7x32 scope mounted and boresighted to my CZ527 today, using nice solid Burris steel rings. The setup looks and feels right, though it certainly adds some weight to the little rifle, but not in an unbalanced fashion. (Someday I'm going to try a Docter sight (Burris FastFire) on it for comparison.)

Alas, when I got to the range to do some test firing, it was closed... so waiting on tenterhooks for the results now.

[Netpackrat]

It's a nice rifle, but for the price I paid, I should not have to be dealing with the annoying little problems that it's had. And I'd kind of hoped for a little bit better accuracy.

[Netpackrat]

And as noted previously Federal American Eagle had .310" bullets, while Winchester JSP (hunting ammo in the silver box) used a .308" bullet.

Earlier this year, I bought a couple more boxes of the Winchester JSP, since it was what had grouped best... My re-test last Saturday showed no changed in group size with the newer ammo, but tonight out in the shop, for shits and giggles I measured bullet diameter of the newer stuff. Winchester is now loading it with a .310" bullet... I'd had the older box for a number of years, so I have no idea when they switched, but the style of the new boxes is different also. Interesting that a change in bullet diameter from .308" to .310" did not produce any significant change in group size.

[Denis]

I finally got my Vortex Viper 2-7x32 scope mounted and boresighted to my CZ527 today, using nice solid Burris steel rings. The setup looks and feels right, though it certainly adds some weight to the little rifle, but not in an unbalanced fashion. (Someday I'm going to try a Docter sight (Burris FastFire) on it for comparison.)

Alas, when I got to the range to do some test firing, it was closed... so waiting on tenterhooks for the results now.

I have now got the rifle test fired and zeroed. It was pretty close after lapping the rings and boresighting - the first three shots of Sellier & Bellot 7.62x39 FMJ made a nice group about two inches right and two inches down at 50 yards, so only a few clicks on the scope were necessary to get it centred for windage and about an inch high on elevation - the next three shots (using the set trigger) made a clover-leaf pattern. The indexable adjustment turrets on the Vortex Viper scope are a really nice touch - you can null the turret scales for the sighting load, so any clicks thereafter are deviations from the tested zero, to which it's easy to return.

I took the rifle to the woods (it's roebuck season until the end of May). The rifle is light and handy. Easy to carry, and short enough it's not awkward for getting in and out of vehicles. The Vortex Viper 2-7x32 scope is good for daytime use, but the objective does not have enough light gathering power for good performance at dawn and dusk (my Minox 3-9x40 beats it hands down - but that is admittedly a bigger and much more expensive scope). I didn't have an opportunity to test ballistic performance on a game animal, but I suspect it will be perfectly adequate with the available S&B softpoint bullets at reasonable (woods) distances.

Verdict - I have a nice, handy, light and reasonably accurate setup for short to medium range daytime hunting. I am pleased.