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hoppdoc
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Re: CZ550 Controlled Feed: Oh Really? [Re: 9.3x57]
      #113642 - 05/09/08 08:25 AM

I am no engineer but I too feel that a CRF should have the capability of "snapping over" and capturing a shell dropped into the the chamber with an open bolt!! Hopefully it can provide this function as well as controlling the magazine cartridges in other situations!!

I would certainly prefer a rifle with a "snap over" capability vs a rifle which would not function in this capacity.

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9.3x57
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Re: CZ550 Controlled Feed: Oh Really? [Re: hoppdoc]
      #113662 - 05/09/08 11:27 AM

Fellas, take a look at Hoppdoc's previous pic showing his bolt.

Here's mine, showing the angled cut at the bottom that prevents the rim from being secured before the case leaves the magazine.

Thanks very much, Hoppdoc, for posting your .505 bolt pic previously.

Here is the bolt from my CZ550, 6.5x55.



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What are the Rosary, the Cross or the Crucifix other than tools to help maintain the fortress of our faith in Jesus Christ, the Son of God?


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hoppdoc
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Re: CZ550 Controlled Feed: Oh Really? [Re: 9.3x57]
      #113665 - 05/09/08 11:57 AM

I now have the gun but have no shells to test yet.

In theory the lower edge of the "flat" boltface would allow straightforward advance of the cartridge upward into position on the boltface as it is moved forward.

My concern is whether there is adequate restriction/hull control to prevent the rise of rear of the cartridge ABOVE the boltface when the cartridge is being moved forward transitioning the rails hull contact points at speed.Perhaps the front of the cartridge is already entering the barrel chamber. We'll see--

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GSP7
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Re: CZ550 Controlled Feed: Oh Really? [Re: 9.3x57]
      #113723 - 06/09/08 08:15 AM

Quote:

Fellas, take a look at Hoppdoc's previous pic showing his bolt.

Here's mine, showing the angled cut at the bottom that prevents the rim from being secured before the case leaves the magazine.

Thanks very much, Hoppdoc, for posting your .505 bolt pic previously.

Here is the bolt from my CZ550, 6.5x55.






That angle cut on your extractor is extreme. None of my several m98 are ground like that. Do you have other m98s to compare too?

I do have one extractor that is bad that I need to replace because the whole claw is ground to short kinda like yours and the case pops out sometimes

Also, I dont know if this hads been mentioned or aware, A mauser 98 extractor and bolt has what Ill call a 1/2 dovetail angle in the grove at the head of the bolt and on the extractor that it rides in. Ruger and CZ(I think also) dont have that feature so the claw head can flex outward and snap over the case head when used like a pushfeed

Edited by GSP7 (06/09/08 08:31 AM)


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9.3x57
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Re: CZ550 Controlled Feed: Oh Really? [Re: GSP7]
      #113729 - 06/09/08 10:51 AM

GSP7:

I have Ruger, 98 and 96 actions and none are ground like this. The gunsmith at CZ said he really had no idea why they make them this way, but they all are, all that is, except the big bore models.

My question is Why make them this way if the extractor won't snap over like mine? Strange.

I need to see if any other extractor; 98, VZ24, Win 70, M17, 96, etc will fit the CZ bolt/action and maybe provide actual CRF.

I plan to try some from my gunsmith who has piles of parts to root thru.

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zimhunter
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Re: CZ550 Controlled Feed: Oh Really? [Re: 9.3x57]
      #113735 - 06/09/08 12:19 PM

Looks like it would only require a little TIG weld on the lower corner to give the extractor an earlier grip on the rim. Shouldn't be a very big job. Get a spare extractor and try it. Shouldn't be a very expensive fix.

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tophet1
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Re: CZ550 Controlled Feed: Oh Really? [Re: 9.3x57]
      #113741 - 06/09/08 01:13 PM

Well I got out my CZ550 .308 and Parker Hale '98 in .243 and cycled it upside down, slowly muzzle down, sideways, fast every way I could. Everything but take it to the loo with me. Not a single round lost.

If Huvius and I end up hunting together upside down, we will still be able to send rounds down range.


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Tatume
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Re: CZ550 Controlled Feed: Oh Really? [Re: tophet1]
      #113772 - 06/09/08 09:37 PM

Another gun that has a very nice controlled-feed mechanism is the Savage 99.

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kamilaroi
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Re: CZ550 Controlled Feed: Oh Really? [Re: Tatume]
      #113773 - 06/09/08 09:44 PM

99s a definite favourite! (esp post WWI t/d 250 savage)

comments or threads anyone?


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9.3x57
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Re: CZ550 Controlled Feed: Oh Really? [Re: tophet1]
      #113776 - 06/09/08 10:59 PM

Quote:

Well I got out my CZ550 .308 and Parker Hale '98 in .243 and cycled it upside down, slowly muzzle down, sideways, fast every way I could. Everything but take it to the loo with me. Not a single round lost.

If Huvius and I end up hunting together upside down, we will still be able to send rounds down range.




tophet1:

Can you take a peek at the lower portion of your CZ's extractor? Is it ground/shaped like the one I posted in the picture or shaped like a 98 extractor?

Thanks for posting. I'll be curious as to whether anyone else can report on the feeding of their rifles, too.

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tophet1
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Re: CZ550 Controlled Feed: Oh Really? [Re: 9.3x57]
      #113825 - 07/09/08 10:42 AM

Ok, I've taken photos,

The left bolt is from my Parker Hale Safari Deluxe (1970's) Ex-Mil mauser '98 action .243.
The right bolt is from my CZ550 (Purchased 2008) .308 with removable box magazine.

Both will snap over a single round fed into the chamber.





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9.3x57
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Re: CZ550 Controlled Feed: Oh Really? [Re: tophet1]
      #113836 - 07/09/08 11:49 AM

OK, I give up...

The gunsmith at CZ told me the detachable mag guns never control feed! UHG!

It's hard to tell, but does look like it might not have quite the radius that my 6.5 has.

And the Parker-Hale speaks for itself, very square and Mauserlike.

Thanks very much for posting!

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What are the Rosary, the Cross or the Crucifix other than tools to help maintain the fortress of our faith in Jesus Christ, the Son of God?


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4seventy
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Re: CZ550 Controlled Feed: Oh Really? [Re: 9.3x57]
      #113865 - 07/09/08 06:46 PM

Regarding the way that the lower part of the extractor is ground away, here are a couple of thoughts.

First, is that these rifles use a staggered cartridge positioning in the magazine, meaning that the cartridges do not slide straight up the center of the bolt face as they are being fed into the chamber.
Each cartridge will come up out of the mag off center and at an angle due to their staggered magazine position.

Second, is that while the '98 style bolt diameter remains the same for different chamberings, the diameter of the cartridges and the cartridge heads do change.
The different diameter cartridges can lead to different width magazine boxes.
This can effect how far off center the cartridge is when it needs to slide up the bolt face and under the extractor claw during controlled feeding.

Third, is that CZ's are mass produced and would require the easiest method to obtain some degree of reliability with feeding as the come from the factory.
I think this could be the reason for that relief at the bottom of the extractor claw.
It could allow the cartridges to feed better from the right side of the magazine, allowing the rim to more easily find its way under the extractor claw as the cartridge is released from the magazine.

All just opinion of course.


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tophet1
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Re: CZ550 Controlled Feed: Oh Really? [Re: 4seventy]
      #113872 - 07/09/08 07:56 PM

Don't look at the extractor, look at the guide 180 deg opposite the extractor on the bolt face. That is where the differences are. I do not know the significance however. I doubt the game will either.

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4seventy
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Re: CZ550 Controlled Feed: Oh Really? [Re: tophet1]
      #113877 - 07/09/08 08:19 PM

You've lost me on this somehow.
I was referring to this quote which I thought was describing the exractor.


Quote:

Fellas, take a look at Hoppdoc's previous pic showing his bolt.

Here's mine, showing the angled cut at the bottom that prevents the rim from being secured before the case leaves the magazine.






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9.3x57
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Re: CZ550 Controlled Feed: Oh Really? [Re: 4seventy]
      #113888 - 08/09/08 12:44 AM

4seventy: I discussed some of this with the gunsmith at CZ. See below.

Quote:

Regarding the way that the lower part of the extractor is ground away, here are a couple of thoughts.

First, is that these rifles use a staggered cartridge positioning in the magazine, meaning that the cartridges do not slide straight up the center of the bolt face as they are being fed into the chamber.
Each cartridge will come up out of the mag off center and at an angle due to their staggered magazine position.

All Mausers with box mags similarly feed, but the extractors on them are not so ground. This confused me and the g-smith as to why CZ would do this.

Second, is that while the '98 style bolt diameter remains the same for different chamberings, the diameter of the cartridges and the cartridge heads do change.
The different diameter cartridges can lead to different width magazine boxes.
This can effect how far off center the cartridge is when it needs to slide up the bolt face and under the extractor claw during controlled feeding.

Third, is that CZ's are mass produced and would require the easiest method to obtain some degree of reliability with feeding as the come from the factory.
I think this could be the reason for that relief at the bottom of the extractor claw.
It could allow the cartridges to feed better from the right side of the magazine, allowing the rim to more easily find its way under the extractor claw as the cartridge is released from the magazine.

Your second and third points are probably near the mark, tho still, other makers have not taken this approach. Post '93, "cheap" Ruger MKII's for example, seem to provide pretty good CRF, at least the ones I've checked mostly do. The CZ gunsmith did tell me that the extractor for the 6.5x55 is the same part as the extractor for .308/.30-06, i.e., "8x57mm Basic Case".

From what I was told some time ago by CZ, tho, CZ550's are NOT supposed to be "snap over" 98's and extractors for the 550 series normally need modification in order to reliably snap over. Thus, we have an extractor grind that may allow the case to pop forward of its grip, but an extractor that isn't really designed to snap over in this event.

It seems that the best normal practice might be to have the extractor altered {if need be} in order to snap over. The gun would then possibly not have CRF, but would at least not allow rim-forward jams. The gun would then function in effect like a SAKO AV; snap-over, non-CRF, but with the controlled-ejection feature common to the Ruger MKII and Win 70 {a feature I have personally always thought was more important than CRF anyhow.}

I myself may look for other extractors that might be "drop-in's" for the CZ550 or able to be altered to fit the CZ action. I have no idea if there are any.

Keep in mind, all this applies especially to the small-caliber guns. The gunsmith told me that the larger calibers {not sure which all are involved here} normally are CRF. This seems to make sense in light of Hoppdoc's pic of his .505 bolt.

Rule of thumb seems to still apply: Check ALL rifles for reliability, especially DG rifles.


--------------------
What are the Rosary, the Cross or the Crucifix other than tools to help maintain the fortress of our faith in Jesus Christ, the Son of God?

Edited by 9ThreeXFifty7 (08/09/08 12:48 AM)

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Ripp
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Re: CZ550 Controlled Feed: Oh Really? [Re: 9.3x57]
      #113895 - 08/09/08 01:27 AM

[quote Rule of thumb seems to still apply: Check ALL rifles for reliability, especially DG rifles.




Read with great interest as I have a couple custom CRF mauser type actions at home--need to get them out and check the bolts versus the photos on this thread...

I am NOT as experienced as most regarding Mauser actions but find it very interesting that they will not feed upside down or sideways???

The reason I asked it is before my last trip to Africa, and I know I will probably be chided for this, but I took my custom shop Remington ..loaded her up with the 416 loads..held it sideways, upside down, and in pretty much every angle imaginable,,no problems feeding what so ever...so again, question the necessity of the CRF..in fact, one of the locals here in MT that hunts DG a lot..bit on the famous side..spent 6 months in "on again, off again" medical care because their CRF Model 70, 375 jammed..and a buff had his way with him for a bit...broken arm, ripped open leg, broken ribs, etc...yikes...

Not arguing at all..I do believe they have their merits..which is why I will take one the next time I go, or at least was planing too until I read this thread.. ....just curious on your thoughts on this...

Thx

Ripp

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Edited by Ripp (08/09/08 02:59 AM)


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9.3x57
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Re: CZ550 Controlled Feed: Oh Really? [Re: Ripp]
      #113912 - 08/09/08 05:26 AM

RIPP:

I agree with you.

A really truly CRF action would be great, but I've always wondered how many truly are and I don't really think the CRF function is that essential. Just my $.02.

I like Mausers, but the CRF feature is neither here nor there to me. I DO like the strength of the 96/98 series extractors. I've never heard of one failing.

But I DO want my gun to work right and not leave me with a round plugging the chamber...

As for the CRF feature, I have heard for so long the droning mantra of how essential it is for DG and the recommendation to always use a 98-type action as if anyole Mauser-type action truly is CRF when in fact the actual gun used may not be. I have no problem with the CRF feature, but if the GUN, the actual GUN, not the theoretical gun, doesn't actually function as a CRF then what the heck??

Meaning of course, I bet many 98's are used by many hunters who think that their rifles are dead reliable "CRF" guns, throw rocks at Rem 700 or Win 70 pushfeeders users for that very reason, when in fact the gun they are using is not CRF and they don't even know it. Just because it is a "98" doesn't necessarily mean anything.

As for the 96/38/46 series rifles, try tipping the gun sideways so the safety lever tips a bit. The lever is not held by spring tension and many are loose. Those that are loose will lock the bolt. Such bolts can't be operated as the safety tipped that way locks it up tight. NO, you cannot function many 96-types sideways!

I gotta wonder how many fellows actually try feeding their rifles sideways and upside down like you did. I bet not many??

I still like the extraction system in combination with the ejector. I like the gun to eject only when I really want it to. That feature tells me its OK to start pushing back. This of course addresses the so-called dreaded "short-stroke", another overblown issue IMO. When I work a bolt fast I'm always more afraid of wrecking the bolt stop than pushing back before I hit it...

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What are the Rosary, the Cross or the Crucifix other than tools to help maintain the fortress of our faith in Jesus Christ, the Son of God?


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Ripp
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Re: CZ550 Controlled Feed: Oh Really? [Re: 9.3x57]
      #113916 - 08/09/08 06:13 AM

Interesting enough, I went to lunch today at the local deli ---went by the magazine rack to get something to read while having lunch...picked up "RIFLE" magazine---really good article in there on this very subject...giving the history of the model 70 from 1936 to 2008 --but also discussed the various mauser type actions including the 550...per the article --is it shown to be a CRF..,mmmm...

Anyway, pretty much the entire issue, which is the October issue, is devoted to discussing various action types...if interested you might want to check it out..I was in a hurry but plan to read it tonight when I head home...

One note I found interesting for those wishing to build a custom..the article stated that Brownells sells both the Dakota and CZ actions...and it states "both CRF actions"...again, mmmmm.....


Later

Ripp

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4seventy
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Re: CZ550 Controlled Feed: Oh Really? [Re: 9.3x57]
      #113970 - 08/09/08 09:53 PM

Quote:

the so-called dreaded "short-stroke", another overblown issue IMO. When I work a bolt fast I'm always more afraid of wrecking the bolt stop than pushing back before I hit it...




I totally agree, as that is exactly how I work a bolt as well.

You know, one of the best and most reliable feeding/extracting/ejecting rifles I've ever used was a "tang safety" push feed Ruger in 300 Win mag.
It didn't come that way out of the box but needed some modification.
I used it a lot right through the 1980's, and also lent it to hunting clients on a regular basis.
It was super slick and totally dependable in all the situations that we put it through.
I foolishly sold it, and later replaced it with a CRF Mk11 stainless synthetic in the same caliber.
The Mk11 was accurate, fed well, and was reliable, but it wasn't half the gun my old original M77 300 mag was.


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Ripp
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Re: CZ550 Controlled Feed: Oh Really? [Re: 4seventy]
      #113971 - 08/09/08 09:59 PM

Quote:

.
The Mk11 was accurate, fed well, and was reliable, but it wasn't half the gun my old original M77 300 mag was.





Unfortunately, IMHO, I think the same can be said about a lot of what is being sold today--yes, they are very accurate but the overall quality of yesteryear just isn't there...economically it probably can't be I suppose...would be far to cost prohibitive...which is why the really good ones now cost what they do...

Ripp

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4seventy
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Re: CZ550 Controlled Feed: Oh Really? [Re: 4seventy]
      #113974 - 08/09/08 10:14 PM

Quote:

You know, one of the best and most reliable feeding/extracting/ejecting rifles I've ever used was a "tang safety" push feed Ruger in 300 Win mag.





My quote above might suggest that I prefer push feed actions, but this is not the case.
I've always (or for a very long time) preferred CRF, have owned quite a few over the years, and the centerfire bolt rifles that I own thesedays are all CRF type actions.


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4seventy
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Re: CZ550 Controlled Feed: Oh Really? [Re: Ripp]
      #113975 - 08/09/08 10:18 PM

Quote:

Unfortunately, IMHO, I think the same can be said about a lot of what is being sold today--yes, they are very accurate but the overall quality of yesteryear just isn't there...economically it probably can't be I suppose...would be far to cost prohibitive...which is why the really good ones now cost what they do...

Ripp




True enough!


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9.3x57
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CZ550/VZ24 Extractor CRF: Oh Really? [Re: 4seventy]
      #114016 - 09/09/08 01:23 PM

Yeah, really.

I fitted a VZ24 extractor to my CZ550 today.

Provides better grip of the case AND I put a bevel on it and it snaps over the case should it get ahead of the extractor.

The VZ24 extractor is a smidgen shorter than the CZ550 extractor, and took a few hours to fit, but it works. In fact, if I got another one after learning the ropes with this one I am pretty certain I could radically improve the CRF. As it is, it feeds with more certainty than the factory CZ extractor and the snapover feature makes it at least as good as a pushfeed in any event.

With VZ24 extractor in place, the gun feeds sideways and upside down {and rightside up to-boot! }, and tosses extracted rounds as far as your bolt speed will chuck them!

Also, factory CZ550 extractors cost $35.00. The VZ25 hook cost me $15.00.

And...

I fixed my CZ extractor to snap over dropped in rounds. I simply took it off the bolt, pressed hard on the buffing wheel for a few seconds and replaced it on the bolt. Now it snaps over.

So much for the incredible amount of skill it takes to make one of these things do so...

--------------------
What are the Rosary, the Cross or the Crucifix other than tools to help maintain the fortress of our faith in Jesus Christ, the Son of God?

Edited by 9ThreeXFifty7 (09/09/08 01:56 PM)


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Ripp
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Re: CZ550/VZ24 Extractor CRF: Oh Really? [Re: 9.3x57]
      #114046 - 09/09/08 10:04 PM

Quote:

I fixed my CZ extractor to snap over dropped in rounds. I simply took it off the bolt, pressed hard on the buffing wheel for a few seconds and replaced it on the bolt. Now it snaps over.

So much for the incredible amount of skill it takes to make one of these things do so...





Apparently your gunsmithing skills know no bounds....


It is unfortunate they just can't do that correctly the first time right at the factory...


Ripp

--------------------
ALL MEN DIE, BUT FEW MEN TRULY LIVE..


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