The Accurate Reloading Forums THE ACCURATE RELOADING.COM FORUMS Rifles Big Bores crf extractorGo | New | Find | Notify | Tools | Reply | |
| One of Us |
on the CZ 550 can you chamber a round that has not been pushed into the mag first? the manual does not address this.I have never owned a crf action before thanks Jim | ||
|
| One of Us |
Some crf you can and some you cant. Dont know for sure on a CZ. My Ruger african will. | |||
|
One of Us |
Yes. All commercial actions that I know of, will allow closing on a round in the chamber. It is the 98 Mauser that was specifically designed to load only from the magazine; German military doctrine wanted only magazine fire. Conversely, US and British tactics called for single loading and keeping the magazine in reserve for emergencies. Which is why the 03 Springfield and early Enfields, had magazine cut offs. Opposite theory of military Infantry doctrine. | |||
|
| One of Us |
Yes White Mountains Arizona | |||
|
| one of us |
| |||
|
| One of Us |
Interesting... White Mountains Arizona | |||
|
| One of Us |
My understanding of the genuine M98 extractor is having to feed from the magazine is not by design but because of the design of the extractor/receiver which is made so there is no room for the extractor to lift above the rim. Thus on a too tight case the extractor has to either pull through the case the rim or break. There is no room in the raceway for it to jump up over the rim. | |||
|
| One of Us |
Except I have about a half dozen Mausers, none modified to my knowledge, and all will snap over a chambered round. Although this is a statistically small sample, I have read others making the same claim. Whatever it was designed to do, there is apparently enough tolerance to allow many to do this. | |||
|
| One of Us |
There is enough room for it to snap over the rim; it is the angle of the lip that needs to be altered so as to make that possible. It is SOP on a Mauser military sporter to do so. No receiver alteration needed. I have never needed to alter one anyway. Not saying none need it; I have not seen all Mausers on the planet, but I have seen a few thousand. | |||
|
| One of Us |
I must say I am repeating what I have read many times. My exposure to M98s could only be described as small. My main CRF experience has been Pre 64, M17 and the later M70 with reintroduced in CRF. My pick is the M70 but because of bedding configuration. | |||
|
| One of Us |
thanks for replies but looking for info on the CZ550 only | |||
|
One of Us |
Call Wayne at AHR | |||
|
Moderator |
uhm, it's a mauser design - like saying one wants to talk ONLY about tires on THEIR sports car, rather than ask what are good tires (given circumstance) it's a 5 minute fix, for a gunsmith - #dumptrump opinions vary band of bubbas and STC hunting Club Information on Ammoguide about the416AR, 458AR, 470AR, 500AR What is an AR round? Case Drawings 416-458-470AR and 500AR. 476AR, http://www.weaponsmith.com | |||
|
| one of us |
That's correct. The CZ 550 Magnum and Medium have an extractor that is a copy of the Mauser 98. Other features on the rifle differ. Over a dozen of the CZ 550 Magnum rifles, bought new in box, have been through my hands. Not one of them would snap over the rim of a pushfed cartridge unless I pressed on the midpoint of that long MAUSER extractor with fingers of my left hand while I closed the bolt with my right hand. I have successfuly bubba-gunsmithed one myself with Dremel tool and file, curving and beveling the bottom, forward, leading edge of the claw, to make it snap over on a pushfed cartridge. If you bought a CZ 550 Magnum that already does this, then your extractor claw has been reshaped from "true Mauser" conformation. I do not know if CZ started doing this at the factory or not, in later years, before they quit making them, just recently.  Rip ... | |||
|
one of us |
Absolutely! Simply bevel the front (barrel side) of the extractor hook so it will slide over the rim of the cartridge, letting the bolt close on the live round. 5 minutes may be more time than needed! ...……......……...…......….  ....Mac >>>===(x)===> MacD37, ...and DUGABOY1 DRSS Charter member "If I die today, I've had a life well spent, for I've been to see the Elephant, and smelled the smoke of Africa!"~ME 1982 Hands of Old Elmer Keith  | |||
|
| One of Us |
thanks everyone for the replies,since this is my first CFR bolt gun (always had Remington's) I was not familiar with is system and the owners manual did not give any info so the best thing was to check with all of you, so thanks for the schooling,by the way just got the rifle back today from the gunsmith that glass bedded the action and it fed 450 gr Barnes TSX bullets seated out to 3.6 in with no problems so now load work starts  | |||
|
One of Us |
No this is not what prevents a Mauser extractor from lifting off the cartridge case rim. The M98 extractor has a an undercut tongue behind the extractor hook with a corresponding undercut groove in the bolt head just in front of the locking lug. As the bolt rotates to unlock these undercuts engage preventing the hook from moving sideways out of engagement with the cartridge rim. The amount of clearance in the raceway has nothing to do with the positive Mauser extraction. | |||
|
| one of us |
Last two cannelures on that bullet are at 3.580" and 3.680" COL with 2.500" brass length. Might as well make it 3.680" in your CZ .458 WIN and you can go all the way to 2450 fps MV and 6000 ft-lbs KE, if you care to. One way to do it: At 3.680" COL, start with 74 grains of AA-2230 and work up, like a good handloader. Rip ... | |||
|
| one of us |
That is true but needs a little more detail. When the bolt is being pushed forward, the undercut tongue in groove actually helps move the extractor away from the center axis of bolt, making for a looser fit of brass under claw. When the bolt is retracted rearward, that is when the claw tightens its hold on the brass, force-vectoring the claw inward toward the center of the bolt's long axis. According to a certain world class gunsmith, there are some milsurp Mausers that have raceways too tight to allow the extractor to snap over the brass in a pushfeed action, even with the "Mauser Extractor Pinch" of fingers pressing the extractor amidships. Apparently in most milsurps and commercial Mausers that is not a factor at all. Just need extractor claw reshaped to snap over rim with dropping a round directly into chamber like a pushfeed. Rip ... | |||
|
| One of Us |
yes loaded one round at 74.0 AA2230 to see what velocity and going to work up from there to max then drop down a hair. anxious to fire it for the first time but it is below zero with a wind chill of -21 degrees will have to wait till Wed supposed to get up to 35 degrees.thanks Jim | |||
|
| one of us |
hydehunter: I had 3 CZ Magnum rifles that would only chamber a round from the magazine. Called CZ and talked to their gunsmith about it, and he had me send my bolts to him and he altered them free of charge. Paul K Take Trophies - Leave Brass | |||
|
| one of us |
We did the picture thing before, here it is again with some notes painted onto them:  . . .  . . .  I do not see how it could be a bad thing to bevel the extractor claw to snap over a pushfed round, other than to say it insignificantly thins the edge of the claw's steel that grabs the rim. It does not necessarily reduce the footprint of the steel or circumference of the brass rim that is being grabbed, if done well. After modification that steel claw will still rip the rim off the brass if the extractor tongue & groove are undercut like on an M98 (milsurp, Zastava/Whitworth, Prechtl), CZ 550, or Heym Express Rifle. Not so with the Winchester M70, Dakota M76, MRC M1999, or FN "Mauser." They lack the extractor tongue & groove undercut. They are CRF but not CRE. All of these CRF actions can be made to snap over the rim of a cartridge dropped into the empty chamber by gravity or pushed in by hand, i.e., pushfed ... unless there is an M98 out there without the room for the extractor to move outward a little bit before the bolt locks down. Semantic or factual arguments anyone ? How much slop is needed in the right raceway at the breech of a Mauser ? Rip ... | |||
|
one of us |
I never put "enough force" to load my .585 Hubel Express push feed style (it has Montana PH action). Good to know it can hold 1+3. Hope I will never need to quickly fire all 4 ;-) Jiri | |||
|
| one of us |
On DG rifles I have seen more fumbles under stress by hunters droping a round in the chamber and it falling out as they closed the action, usually while looking at the buffalo with the barrel pointed upwards to one degree or the other..I have also seen a couple of cut extractors peeled and a case stuck..I have had happen to me and seen happen to others when chambering a non control feed rifle at a run, the round falling out on the ground.. BTW, in tests Ive conducted, its faster or just as fast to push a round in the magazine and close the bolt with a crf rifle.. My opinion is based solely on my experiences in 60 or 70 plus years of hunting and being in the hunting business for for 40 years, others may differ, and my observations are not scientific. Ray Atkinson Atkinson Hunting Adventures 10 Ward Lane, Filer, Idaho, 83328 208-731-4120 rayatkinsonhunting@gmail.com | |||
|
| One of Us |
I recently saw a picture of extractors from days of yore in production, being made 3 at a time out of round stock. A fascinating looking process. Not sure if they are still made rhat way. | |||
|
One of Us |
Facinating reading! Many years ago I bumped a cartridge ahead of the extractor in a 1951 FN Mauser .30-06 - but didn't try to force the issue, getting the round out with a pocket knife. Last week one was somehow slipped into the breech of my Zastava 9.3x62 and, knowing the range officers get grumpy if anyone takes a cleaning rod to the muzzle, recalled you guys saying some commercial Mausers would snap over the rim. So, I gave it a go and it worked. Now, looking at the bolts of these two rifles, I see both have the tongue flaring on the front side to grip the groove. Both bolts have drill holes towards each end of the grooves but only the FN's groove extends beyond one of them to enable stripping the extractor. Does anyone know how Zastava would get their tongue in and out of the groove? Also, I notice the lower, lead-in edge of the Zastava extractor claw has been bevelled away more than the FN. While I guess this would help in snapping over rims, it would have less purchase in pulling out troublesome cases. That said, I'm inclined to agree with Atkinson, that in the world of DG hunting sticky handloads should be less likely than a nervous user misfeeding his rifle. | |||
|
| One of Us |
I am just glad that I prefer Push Feed. Although having said that I like things that match. If I had the money for a real top end gun and it was to be 300 H&H or 375 H&H, then a CRF and M70. | |||
|
| one of us |
Apparently, FN made both a military-type M98 with undercut extractor tongue&groove (like yours), as well as a commercial M98 with no undercut (like mine). Also, the amount of reshaping of the extractor claw to make it pushfeed capable on an M98 seems to be highly variable, and dependent on the skill of the gunsmith. I.e., it can be done with very little decrease in the fraction of the rim circumference covered by the claw. Here is an original (1936) Oberndorf Mauser M98 from member LHeym500, it is a beauty:     Looks like that claw grabs at least a quarter of the circumference of the rim, Mike, take note. Also looks like it is not meant to snap over the rim of a pushfed cartridge, since it has a big, flat, forward face of the claw with little bevel on the inward edge of the claw and little rounding off of the bottom edge of the claw. It might still be able to snap over a pushfed cartridge rim if the "Mauser Extractor Pinch" is used to top off the full magazine. Rip ... | |||
|
| One of Us |
Rip: I know you have tried before. But could you please explain for us slow folks what is Controlled Round Extraction? What are you looking at to know which has CRE? Thank you. | |||
|
| One of Us |
The extractor will have an angle on the part just aft of the extractor blade. That engages an angled cut in the bolt body that it rides in. When the bolt is moved rearward, these two angles engage so that the extractor blade is forced toward the centerline of the bolt, thereby ensuring the extractor blade will not slip over the rim of the cartridge. When the bolt is pushed forward, these two angles are somewhat free so that the extractor blade can move outward slightly to snap over the rim. Winchester’s and dakotas do not have this feature. Mausers and true derivatives do I think that’s close... | |||
|
| One of Us |
| |||
|
| One of Us |
Thanks RIP, that extractor goes midway between my military FN and the modern Zastava's. | |||
|
| one of us |
What BaxterB said and this: It is that undercut extractor tongue (some call it a foot) that rides in the undercut groove around the bolt body. When you pull the bolt back, it makes the extractor claw move inward toward the center of bolt face, gripping the cartridge more tightly in extraction. I don't know if I made up the term "controlled round extraction"/CRE or someone else did, but it is a good term. I am sure your Oberndorf Mauser is CRE as well as CRF, of course. No pushfeed without the Mauser Extractor Pinch "MEP" I bet. Maybe I made up MEP too. But it is a good term.    Rip ... | |||
|
| One of Us |
I recently saw a picture of Mauser extractors in the making and before they were cut apart. They were made three at a time out of round stock. Internal stuff cut before being separated by longitudinal cuts. Had no idea they were made that way... | |||
|
| One of Us |
Rip and Baxter. I think I see it. It is the right angles created at the extractor foot or hook and the grove the extractor foot, hook, tongue, or whatever one calls it rides in. When the bolt is brought out of battery and moved to the rear, the hook grabbing the rim is compressed into that grove securing the cartridge for more preasure/Force to extract the case. How far off am? Did I get it? | |||
|
| One of Us |
I think you got it. It’s a pretty ingenious idea. Especially since its designed to work differently if the bolt is being pushed or pulled. Smart dude that Mauser | |||
|
| one of us |
Agree, LHeym500 has it, the push and pull effects are different, and Paul Mauser was brilliant. When the bolt is pushed forward that undercut extractor tongue&groove allows the claw to move away from the centerline of the bolt, loosening up to allow the cartridge rim to more easily slip under the claw. Reverse direction of bolt travel, pull bolt backward, and the claw grips the rim tighter for extraction.  An extractor claw like on LHeym500's Oberndorf Mauser was modified to this on my M98 Magnum Mauser for .450 Dakota, at the factory:    Hey, it is not a Heym, and it is not a .458 WIN (sigh) but it will make do. Rip ... | |||
|
| One of Us |
Guys. Thank you very much I learned something. Thank you. | |||
|
| Powered by Social Strata |
 | Please Wait. Your request is being processed... |
|
Visit our on-line store for AR Memorabilia