The Accurate Reloading Forums THE ACCURATE RELOADING.COM FORUMS Rifles Big Bores Re: Push vs. CFRGo | New | Find | Notify | Tools | Reply | |
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Quote:Quote: First off if you don't know the difference between CRF, and PF, how do you know the guide was useing a CRF rifle? The CRF will not jam with a short stroke! Exactly what rifle was your guide useing?  As to the physical differences, the name alone should tell you something! One (CRF) has control of the round from the time it is released from the magazine till it is either chambered, fired, or ejected from the firearm! The other (PF)only gets control of the round once it is chambered, and the bolt handle turned down. Then and only then, does the round become controled in any way, but actually is not controled even then! It depends on a springed plunger to eject the empty, which is not all that dependable. With the former (CRF) the round slide it's rim under the extractor, even before it is out of the magazine box, and if short stroked,(drawn back with out chambering) will simply eject the loaded cartridge, and pick up a new one on the second stroke! With the latter,(PF) if it is short stroked it leaves a round in the loading rails, and another round is stripped off the top of the magazine on the recycleing, now you have two rounds in the rails, vieing for ONE chamber! If the bolt is jammed forward with two rounds in the tray, it will cause a jam that requires tools to undo! If a rifle is fired and the bolt is not drawn back far enough to get a new round, it makes no difference which type you are shooting, because neither will be reloaded! This is not what is meant by SHORT STROKEING, in regard to jamming! Many people believe this what is meant by the phrase "short strokeing", and if that were the case, neither would be superior to the other! The common reason for short strokeing is, nerves, when the rifle is applied to dangerous game! The rifle is fired on the animal, and because of the danger envolved, the shooter, eger to get off a second shot, ejects the empty, and begins the return to battery with the second round. Being is such a hurry, he doesn't chamber the second round, but withdraws the bolt, before it is chambered. With the CRF, the loaded round will be ejected, and is out of the way, where the PF leaves the unchambered round in the loading rails, to be joined by the next round. The CRF has a solid ejector that is attached solidly to the action body, where the PF has a spring loaded plunger that is easily frozen by crud, dust,and ice so it many times doesn't work at all. Additionally, it is impossible to strip another round off the top of the magazine box, unless the preveous round, or case is ejected from the bolt's hold on it. this means there is no way to get two rounds in the loading rails of a CRF rifle. it is idiot proof! Not so with the PF as it has absolutel no control of the round till the round is chambered, and the bolt handle turned down. The only reason to build a rifle with PF action is to improve the bottom line of the manufacturer, not to benefit the buyer! You cn hunt dangerous game with a push feed rifle, many do, without a problem, but why take a chance, when it cost the buyer no more to have CRF! Paul Mauser's old system has never been improved on since 1898 when the system was perfected! Certainly, Push feed was not an improvement of anything above profit for the maker!  | ||
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One of Us |
Would someone explain (to a new guy) the difference between push-feed and CRF I did a search and found no joy.Why is CRF better for DG (at least I talk the talk) TIA | |||
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lol! Are you serious? I found these under African Big Game: http://www.accuratereloading.com/ubbthreads/showflat.php?Cat=&Number=53385&page=&view=&sb=5&o=&fpart=1&vc=1 http://www.accuratereloading.com/ubbthreads/showflat.php?Cat=&Number=37166&page=&view=&sb=5&o=&fpart=1&vc=1 http://www.accuratereloading.com/ubbthreads/showflat.php?Cat=&Number=27452&page=&view=&sb=5&o=&fpart=1&vc=1 This thread is interesting too, it has a little blurb about CFR vs. Push feed. http://www.accuratereloading.com/ubbthreads/showflat.php?Cat=&Board=UBB54&Number=643118&page=0&view=collapsed&sb=5&o=31&fpart=all | |||
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You obviously ain't searched enough. That is "CRF" not "CFR." Controlled Round Feed is indeed best for dangerous game. Search some more, then if you still don't get it, someone with too much time on their hands will explain it to you. Gotta go. | |||
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Quote: Glad I could brighten your day... not to be rude, but RTFP. I read the threads you've posted and altho' there's great debate and great arguments for having CRF in a DG rifle there's not much explanation as to the mechanical differences. I'm not specifically looking for Cadd drawings or computer simulations of the differences, and if you don't know, that's OK. So far I've found a lot of opinion and not too much fact. and that might be the end of it. Apparantly CRF eliminates some of the potentials for misfeeding rounds. That seem to be the consensus. Altho' the guide in AK got was mauled because of a mis-feed/short stroke with a CRF gun What are the physical / mechanical difference in how the gun operates? That's the first question in my post. | |||
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| One of Us |
In a controlled feed, a claw extractor grips the case rim as the case movees out of the magazine and has control of all of the way into the chamber,while the round is in the chamber, and as it is extracted until ejection. In a push feed, the extractor pops over the case rim only when the cartridge is all the way in the chamber. Further, a controlled feed extractor grips quite a big larger area of the case rim than a push feed extractor, so if for some reason your case decides to stick in the chamber, a controlled feed extractor has a much better chance of getting the case out than a push feed extractor. Some push feeds are more reliable than others. Rem700's are generally considered pretty weak in the extraction dept, but Sakos are pretty good. | |||
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| one of us |
Be more specific next time. Maybe learn to use the "search"? | |||
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| One of Us |
Further, a controlled feed extractor grips quite a big larger area of the case rim than a push feed extractor, so if for some reason your case decides to stick in the chamber, a controlled feed extractor has a much better chance of getting the case out than a push feed extractor. A PF also applies a twisting force to the case. | |||
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I believe the guide who got mauled in Alaska was using push-feed rifle. | |||
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| Moderator |
Quote: Yes, I believe it was a Sako. George | |||
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With PROPERLY set-up rifles I have seen absolutely NO benefit with the CRF. In reality, the CRF has MTTGW (more things to go wrong) with it! They are sensitive to many many things, don't let these guys fool you. Extractor groove dimensions and contimination in the extractor groove can be terrible problems. Most seem to modify their CRF rifle to work as push feeds too, this leads to a REAL POS (piece of shit) PF rifle since the CRF magazine is NOT designed to properly feed as a PF. There are MANY good reasons that EVERY military on earth has left the CRF behind! You can design auto loaders to work with a CRF style extractor, it can be done. So ask yourself why it hasn't. With regard to the searching. There is plenty of opinionated BS on many threads here at AR about this topic. There is also a TINY bit of truth. Spend about four days reading it all and you may find that "needle in the haystack" of truth. By the way, using the proper bullet for job and puting THAT bullet in the RIGHT place are both FAR more important than the CRF vs PF BS debate!  Enjoy. ASS_CLOWN | |||
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The CRF has two pluses over PF although one of these pluses might not apply to most American shooters. Firstly, they are better than PF for running cartridges through the magazine since the bolt does not need to be turned down Secondly, when you are spotlight shooting they are good because a cartridge can be in the chamber but with the bolt up. That is OK in a PF but it is not as simple to get the cartridge back out, especially at night in the back of a 4 wheel drive. In the world of accuracy and switch barrel guns PF is much better because you can setup to swap barrels between actions, the extractor slot is the problem here for CRF. Mike | |||
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Quote: Please expound on that, I'm curious. Chuck | |||
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Chuck So that a cartidge can be dropped into the action and the bolt closed, as opposed to feeding from the magazine. Mike | |||
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That sure doesn't make it a push feed. Chuck | |||
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| One of Us |
Not in the sense that it will function as CRF when cartridges are loaded from the magazine. | |||
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Quote: Add this to it. Chuck | |||
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It is not as simple as it sounds. Paul Mauser experimented with push feeds for thirty years before concluding that they could not prevent human error. It took an additional five years to perfect the CRF rifle, the model 98. One really has to handle a quality 98 in it's original chambering to fully appreciate the design. The cartridge is controlled by at least two opposing contacts the entire time it is in the rifle. Auto rifles that cycle in 1/10 second are not prone to human error, so a CRF is not necessary. Most CRF rifles designed after the 98 do not have all of Paul Mauser's original features or quality, and have to be judged on an individual basis, not as a general class. To experience the ultimate CRF, try an original Mannlicher-Schoenauer (1903-1969). It combines a claw extractor with single stack feeding from a rotary mag, along with incredible quality. However, they do not make good DG rifles because the tolerance are too tight and the parts are too intricate. Basically, you cannot just compare CRF and PF rifles in general. There are quality and junk versions of each. It is more beneficial to your particular needs to compare individual rifles. Personally, for my money I would not consider anything but an original Mauser, Brno or M-S rifle. The Winchester and Ruger CRF rifles have deviated too much from the original 98 design. | |||
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KurtC, Quote: Now that is about the most inaccurate / grossly ignorant statement I have heard here at AR in quite sometime! Autoloaders can and do most certainly JAM/misfeed! Most firearm jams have little to do with human error, at least in my personal experience! I can think of one autoloader in particular, though bragged about constantly on military forums, that is a misfeed-o-matic (no it ain't a AR15). It is still fun as hell to shoot though. It does a wonderful job of put about a 20 degree bend in the cartridge. OUCH Mausers can and do most certainly jam/misfeed! The only human error is short stroking, BIG deal! There are MANY MANY other pitfalls that the mauser design can fall into! You have addressed one! Typical AR BS and opinion, not based on ANY facts just hearsay crap. Now I think I have done my part in helping you all beat out the SMK are hunting bullets thread. ASS_CLOWN | |||
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Once again and as usual ASS CLOWN, your ignorant clown ass and battle ship mouth has overloaded your rowboat ass, and you don't know what your talking about, and your rudeness to Kurt really tops it off.. Kurt is 100% correct in his post and your just repeating some off the wall BS you read and have no clue as to its practical application, nor its legitamacy, again as usual... I, personally, would never hunt dangerous game with a push feed rifle, but if one likes them then thats his business, not mine. I see push feeds fail regularly, I see rounds fall out of the magazine while the client is watching the animal, while he closes the action and "Click" is the result, and yes it has happened to me on two ocassions a long time ago..I see double feeding, I see broken extractors on rare ocassions... I have seen very, very, few failures with control feed rifles, but yes I have seen some, but only from actions that were not right from the beginning...I have never had one of my personal control feeds rifles fail except when a set of scope ring levers blocked the bolt uplift.. I will advise anyone to take advantage or other peoples mistakes and learn from them, and to learn from their own experiences, and most of all the best advise is "get all the edges in your favor", and a push feed is the place to start, trade it for a control feed rifle that is properly set up right...test it plenty before hunting dangerous game.. | |||
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Quote: I agree, which is one reason I do not like Model 70's or Dakotas. I build my most of custom rifles from military 98 actions so that I get the full advantage of Paul Mauser's design and safety features. | |||
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Quote: Thanks again for your insightful response... Now, back to the actual subject | |||
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Thnaks, everyone (most everyone) for the clarification. I was testing my Vanguard in 300WSM (a PF gun, I'm trainable at least) and with constant forward motion I could NOT get it to fail, in any position, upside down included, at any feed speed. Only when I would partially feed a round then "back-up" and feed another round into it was there a problem. I had incorrectly assumed the "short-stroke" was on the extraction cycle and not the feed cycle This was most pronounced with the muzzle down as the round would fall into the chamber after about 3/4" of bolt movement. Question: I don't have, or have access to a CRF gun. How does the "Claw" capture the round at the time of feeding? Lastly, I ment this to be more of a "this is how it works" thread as the "this gun in better than that gun" subject has been beaten to death Thanks to all  | |||
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Ray, I liked that post. Alot! Chuck | |||
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With a proper CRF, the cartridge rim slides up under the extractor just as it leaves the tension of the feed rails. This is where some "CRF" rifles drop the ball. It doesn't take more than a few strokes of a file to ruin the timing. The rails of each rifle have to be shaped for that particular cartridge. A lot of them feed perfectly from one side, but not from the other. I'll try to post some pics showing this. It really is remarkable to observe a 98 or an M-S feeding in slow motion. | |||
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Ray, I see rounds fall out of the magazine while the client is watching the animal, while he closes the action and "Click" is the result But Ray surely that is only what Kurt is saying, that is, individual rifles etc. For example, there is no way the cartridges will pop up out of any 378 based Wby with their single stack magazine but of course that is not a product of the Wby being a push feed. Mike | |||
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| <allen day> |
Ray, I agree with you completely. I have found that a lot of the smug arrogance that comes out of the push-feed camp stems from ignorance and/or improvidence. AD | ||
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Quote: Thanks, ALOT I was thinking that had to be the case, and the feeding from one side or the other makes sense as well | |||
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Collins, Hopefully you will find a picture worth a 1000 words. This is how a CRF rifle feeds, it starts off just like a PF. First round engaging the bolt face:  The round is pushed forward, when it comes free of the magazine lip (pops up is a more accurate phrase) it is captured behind the extracto claw on the one side and the bolt rib on the top and off extractor side. Here is the first round immediately after coming free of the magazine:  Another shot same round:  Round number two:  Round number two coming free or the magazine:  Hope those pics were helpful. Ray, I loved you last post too. Typicall opinionated hogwash, IMHO. I have seen many many CRF rifle misfeed and I have seen numerous PF misfeed too. It seem to all average out to both feed systems feed well IF PROPERLY set-up. ASS_CLOWN | |||
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Thanks more than 1000, So if you feed it an inch or so and then extract, will it eject just like a spent round? (not like a PF) | |||
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Collins, When you do get the chance to examine a CRF, don't be surprised if it doesn't look exactly like the above pictures. Those rounds are pretty large and there is less lateral movement involved. Standard size cartridges will slide under the extractor a lot further forward. The photos illustrate why a claw extractor is not enough, the feed rails must be in perfect shape for everything to work as designed. Ass, I think I wasn't clear enough. All rifles are subject to mechanical failure. Dirt and damage are the usual culprits. However, the CRF was designed to reduce malfunctions caused by human error, when working the bolt. An autoloader by nature removes the possibility of human error by removing the human from the cyclic action. The first thing a troop is taught in BRM is to never ride the bolt home, it will cause a jam. Putting a CRF into an autoloader would solve nothing, in fact the extra friction would slow the action down. Ray, Thanks. | |||
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Collins, That is correct, once the cartridge has come free of the magazine lips and is captured by the bolt / extractor it will eject just like a fired round. However, if you pull the bolt back before the bolt / extractor has gripped the cartridge there is a chance (particularly if you are rough handling the rifle) that the cartridge could pop out of the magazine. For this reason some people butcher their extractors so that they can force this loose round into the chamber. My rifles will not let you do this, if you try and force a round into the chamber which has not been first captured by the bolt/extractor claw you will jam the cartridge into the rifle's barrel and it WILL NOT fire, not will the bolt close!!! Got yourself a real expensive club then. The truth is both the CRF and the PF have their idiosyncracies. The operator MUST work within these boundaries if the intent is to have trouble free operation. By the way, ALL my bolt actions are CRF mauser derivatives. Not that I would not own another PF bolt rifle, as I have owned several some real big bores too (460 Weatherby comes immediately to mind). I just like the mauser style action better, and am quite frankly far more "comfortable" with it since it is the bolt action I have the most experience with. For the the tube magazine is the root of all evil, but that would be another thread. I really cannot stand pump actions at all.ASS_CLOWN | |||
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Quote: If I can clear that "expensive club" in five seconds of the offending round using nothing but that rifles mechanical abilities and my hands can I have it? Chuck | |||
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Chuck, I don't think you could get one unstuck with the extractor in less than 5 seconds, if it was stuck in the manner I imagine. It won't come out anywhere near as easily as a 8X57 or -06 would. Besides all that, in a dangerous game situation you don't have 5 seconds to clear a jam. So what does that mean, you NEED to know how to use your rifle properly in the first place, regardless if it is a CRF or PF. Are you sure you could handle that rifle anyway, or even want to try? Kurt & Collins, Should I post some pictures of a CRF feeding rounds of slightly less girth and length? Let me know, it won't be a problem. ASS_CLOWN | |||
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Quote: Nope. those were fine, great in fact. Ya gotta love this digital age... Now if you wanted to do a movie | |||
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Quote: I don't believe a push feed provides any twisting force to the case head at all , UNLESS , there is a massive overload that swells the case head or rim tight into the bolt face.... Also , Mike , a Mauser 98 with the inner reciever ring would work splendidly as a switch barrel , in fact I believe it would be superior in that respect to any M-700 type breeching system . You would only have to worry about the extractor cut with a M-70 style or cone breech...... | |||
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Quote:Quote: Wrong. A push feed is exerting a rotational force to the case (as the bolt is closed) and is popping the extractor over the case at the same time. | |||
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| one of us |
I believe Mike was refering to a twisting force as the bolt is opened , at any rate I believe you are off on that one ; any twisting force from a push feed extractor against the case as the bolt is closed will be minimal at best and pretty much nil in effect........ | |||
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THe rotational force is exerted by the boltface contacting the case head and by the extractor. It is not of sufficient magnitude to cause any harm, but the force is there nonetheless (note - a previous post denied that there was any such force). | |||
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