Strength question of CZ 527

[homesick]

I traded for a CZ 527 Varmint in 223 Rem. it has proven to be very accurate and a joy to work up loads with. Here's my question the other day a guy at the range told me the CZs aren't a very strong action. I have looked on the web for any info on this and have not found any thing to confirm that.
As an added note I have found most loads that shoot the best are 1 to 1 1/2 grain below max. and even at book recommended max loads it shows no sign of pressure (not even a flat primer).
My question is has any one experience with a CZ or have you heard any thing.

 

[eastbank]

they are very good actions and will handle any load in the loading manuels with ease, but you should work up to the higher loads as with any rifle reloads. mine is a 7.62x39 carbine and it has not given me any problems at all even with stout reloads. eastbank.

 

[10-96]

I've not heard anything about CZ actions being weak either. And, I run my reloads pretty close to max as well. However, you really can't tell much about the integrity or strenght of an action by looking at the brass and primers.

I've kinda got my own theories about CZ small mauser actions... CZ's built and designed in CZland (just ain't gonna try to spell it correctly folks) where ammo tends to be loaded to a bit higher levels than SAAMI specs here in the States. My guess is they were built to handle some pretty stout stuff. I know it's bad science and bad mojo to think this way- but if you've ever fired a surplus, european, or surplus european 8mm Mauser, 7mm Mauser, 6.5Sw Mauser or .303 Brit either right before or right after a U.S. loading of the same ctg, you'll see and feel quite a difference (and a bit of disappointment that us Yanks are limited to weenied down ammo).

 

[Art Eatman]

I did a quick read, not being personally familiar with that rifle.

http://gunsmagazine.com/cz-527/

The strength of an action usually has to do with rearward thrust on the bolt, which for a .223 is quite small*. As long as the case does not rupture, strength is not an issue. If the case does rupture, venting is the issue, not strength. Generally, rifles are proof-tested to at least 50% above factory-spec loads--or the design is, at least.

* Hunt up the ID of the case; probably around 0.3". Figure the area (a fraction of a square inch) and multiply by the chamber pressure. That gives the rearward force.

 

[Rimfire5]

I have a CZ 527 with the varmint barrel and the Kevlar stock. It too is a very accurate rifle and is most accurate in the mid range of loads with most powders.
That equates to the following range of the 25 best loads by bullet weight that average 0.296 overall to be:
40 grain bullets - 3237 to 3500 fps
52 grain bullets - 2900 to 3359fps
53 grain bullets - 3050 to 3100 fps
55 grain bullets - 3100 fps

I have tested 290 different loads that average 0.503 inches overall at 100 yards so not all of the loads were world beaters.

Seven of the top 10 loads are with N133 powder, two with H335 , and one with CFE233. Seven are with 52 grain bullets, 2 with 40 grain bullets and one with 53 grain bullets.
The top 10 loads average 0.247 for 35 groups.

If you are looking for accuracy, being in the middle of the load tables is a good thing. It keeps the brass in better shape for reloading and takes a lot of high velocity stress off the rifle. I get more than 16 reloads out of Lapua brass in my CZ. The primer pockets wear out before the brass loses the ability to keep neck tension.

If you are looking for velocity, especially for hunting, then carefully test different powders with your hunting bullets to see which one delivers the best accuracy at a velocity that provides the kinetic energy on target that you are trying to achieve. Practically, hunting accuracy probably will not be as big an issue since you are going to introduce more variations in set up than you would on a bench testing load accuracy, but as long as your groups stay in the killing zone, the target won't know the difference.

 

[DPris]

The guy at the range was wrong.
CZ Mauser-based actions are quite strong.

These are quality guns, not weak, not fragile in any way.
Denis

 

[Magnum Wheel Man]

I agree, just cause somebody say's something, doesn't make it so...

if the guy had any knowledge at all, perhaps he was just stating that the mini Mauser wasn't as strong as their full sized / magnum actions...

which I would assume to be true, & obvious

 

[homesick]

Thanks for your responses, as I stated my loads are mild at best. My best test results have all come in at 1 to 1 1/2 gr below suggested max. It also likes the 52 grain boat tail Sierra the best. I have been using 8208 BXR and Benchmark. I'm using Remington brass picked up at the range and have not been real particular about the condition of it as long as the necks and shoulders are right, most are once fired factory. Most test loads are under 1/2" MOA and a couple are at 3/8".
The rifle is very well balanced doesn't handle like a medium heavy barrel rifle, has good wood to metal fit, single set trigger which is very crisp when set, and is free floated. I'm a die hard Remington / Ruger fan but this little jewel really opened my eyes.
It's been a long time since I would go to the range with test loads and can't even get home before I'm thinking of new combos to try.