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Discussion Starter #1 (Edited)
Getting to the Extraction Point...

Any operator will tell you that it's foolish to embark on a mission without a good plan for extraction once the objective has been accomplished. Similarly, it's foolish to design a firearm without serious consideration for the extractor, whose primary job is to remove the fired case before a fresh cartridge can be deployed. It's not an analogy we can take very far, but it does serve to illustrate the critical nature of this seemingly humble part. Just as the best rescue team may fail without a plan to get them out of harm's way, so a gun may fail without a well designed extractor.

The funny thing about cartridge extractors is that unlike, say, a highly trained air crew tasked with extracting a SpecOps team, a cartridge extractor is involved in nearly every phase of the mission. Cartridge extractors are necessarily located on one side of the bolt face--typically the outboard side--so that they can grasp the rim of the case and hold it securely until an ejector dislodges the case and flings it out of the action. In this position, the extractor, whether it wants to or not, also plays a role in feeding.

In order to perform its primary function, an extractor claw must reach inboard closer to the firing pin hole than the case rim's outer diameter. Naturally, this means that during feeding the case rim and the extractor claw will be vying for the same spot on the bolt face. One of them has to give way.

There are two basic types of extractors that offer two different approaches to this little "traffic incident."

1) The first type is a "push feed" arrangement. It might be more accurate to describe this as an "interference extractor" arrangement. In this arrangement, the extractor, with a spring forcing it inboard, temporarily displaces the case rim to the inboard side of the bolt face until the cartridge is forcefully aligned with the bore/bolt centerline near the end of the chambering process, finally pushing the extractor aside. Once the cartridge is fully chambered the extractor will snap over the case rim as the bolt goes into battery. This arrangement is generally quite reliable in its primary extraction role, but because it introduces some degree of cartridge misalignment during feeding, it can be problematic.

2) The second arrangement is referred to as "controlled round feed" (henceforth CRF). With this setup, the extractor and bolt face are designed in such a way as to allow the extractor claw to take its controlling position over the case rim as soon as the cartridge is delivered to the bolt face by whatever magazine feeding arrangement exists.

CRF has two advantages:
1) It mitigates cartridge misalignment with the chamber/bore/bolt face, and

2) by taking control of the case rim immediately, it eliminates play time for the cartridge making its way from magazine to chamber. Think of it as a bull being forced through a chute directly from pen to trailer. The bull has no choice. With push feed, there is the possibility, however small, that the bull may veer off course, because there is no chute, just a couple of cowboys with cattle prods.

This is not to suggest that push feed or "interference" arrangements are hopelessly inferior and unreliable. In fact, they are employed in the great majority of manual action rifles, and quite a few self loading rifles to boot. As we are aware, this works out fine 99.9% of the time.

There are a few rifle types that employ CRF, and it is my understanding that dangerous game hunters--if they choose a bolt action--insist on CRF bolts as insurance against feed failures in a life and death situation. The downsides to CRF are that such an arrangement typically requires careful tuning to function smoothly, and even with careful tuning, there is often a resultant small "hitch" in the feed process as the case rim moves into position inside the spring loaded extractor claw.

In contrast to rifles, the great majority of semi-auto pistols (I'm having trouble thinking of an exception) employ CRF by necessity. With pistols, there is a long jump--relative to the cartridge's short length--from magazine feed lips to chamber, both forward and up. Without the extractor's control, the pistol bullet would veer steeply upward as it left the magazine lips and hit the feed ramp, likely missing the chamber mouth altogether. The CRF extractor claw forces the case head against the slide breech face and into alignment with the chamber. However, as with CRF rifles, pistol extractors can require some careful tuning to work smoothly and reliably, particularly--but not limited to--older designs.

In fact in my experience, the number one cause of feed malfunctions in virtually all types of repeating arms is the extractor. That's how critical this little part is. But wait, there's more! Not only is the extractor responsible for a great many feed malfunctions, but also quite a few ejection malfunctions as well. How's that?

Well, most ejectors--the part which forces the empty brass to be flung out of the action--are pretty rudimentary devices, typically employing either a spring loaded plunger or some type of stationary bump stop. In any case, this simple device must push against the case head opposite the extractor claw, forcing the brass to pivot outward, with the claw as its fulcrum. If the claw fails to maintain case rim control long enough for the ejector to force the pivot, then brass may stay in the action, stovepipe, or in the best case scenario, just dribble out of the ejection port.

As you can see, the seemingly humble cartridge extractor is not so lowly a player. In the SpecOps mission scenario, the extractor is not just the air crew standing by to yank the rescue team out of hostile territory, it is also the mission coordinator. As such, it has more than one way to fail: too little involvement--mission fail; too much interference--mission fail; weakness in the face of adversity--mission fail; bad timing--mission fail. FAIL, FAIL FAIL.

There is only one way for the poor ******* to bring home a successful mission, and that is to do everything right, every single time, time and again, with no hope of promotion and very little hope of recognition. Heck of a job. At least you appreciate him now.


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RangerPointStore - M/94 Extractor Claws

Up next this weekend. We’ll be announcing the availability of our evolutionary new extractor design that finally addresses Marlin 1894 extractor-related feeding issues! Here's the previous discussion thread http://www.marlinowners.com/forum/ranger-point-precision/364274-here-last-evolution-1894-a.html


Adam
 

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Most stoppages are a failure to extract fully. Israeli designers know this which is why their weapons try to put the spent cases into low earth orbit.
 

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All kinds. Enamored of their mechanisms!
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A correctly designed extractor will grip the cartridge tighter as the bolt pull increases not depending on just spring pressure. The culmination of the Mauser, in it's 119 years ago introduction of the '98 series featured a critical, little mentioned feature by today's gun writers of a dovetailed lug just behind the claw in the extractor and a female clawed groove near the bolt head. The harder the Mauser 98 bolt tugs a stubborn, stuck cartridge, the harder the extractor grips.

Unfortunately designs based on the '98, such as the Pattern 14/1917 Enfield, Springfield 1903, Winchester M70, and the Ruger 77 series have omitted this difficult to recreate dovetailed groove. The quality of these guns relegate them to what I consider sup par in the extraction department, though their overall quality sets them apart from the masses mostly due to their quality of manufacture and the modern ammunition available today. The extractor in the newer guns can pop out of the cartridge rim from forces impinged upon the by sticky extraction.

In pivoting extractors the location of the pivot fulcrum can be designed to accomplish the same thing. The AK47 as a point of such a feature. The SKS system is one of my favorite gun using a mechanical camming design appears to be the most rugged I have surveyed to date. Check that one out!.

It would be nice if such a feature could be incorporated in the Marlin system.

AC
 
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Discussion Starter #6
A correctly designed extractor will grip the cartridge tighter as the bolt pull increases. The culmination of the Mauser, in it's 119 years ago introduction of the '98 series featured a critical, little mentioned feature by today's gun writers of a dovetailed lug just behind the claw in the extractor and a female clawed groove near the bolt head. The harder the Mauser 98 bolt tugs a stubborn, stuck cartridge, the harder the extractor grips.

Unfortunately designs based on the '98, such as the Pattern 14/1917 Enfield, Springfield 1903, Winchester M70, and the Ruger 77 series have omitted this difficult to recreate dovetailed groove. The quality of these guns relegate them to what I consider sup par in the extraction department, though their overall quality sets them apart from the masses mostly due to their quality of manufacture and the modern ammunition available today. The extractor in the newer guns can pop out of the cartridge rim from forces impinged upon the by sticky extraction.

In pivoting extractors the location of the pivot fulcrum can be designed to accomplish the same thing. The AK47 as a point of such a feature. The SKS system is one of my favorite gun using a mechanical camming design appears to be the most rugged I have surveyed to date. Check that one out!.

It would be nice if such a feature could be incorporated in the Marlin system.

AC
Keen observations here GSG. Part II of this post will be about more specific features and design elements of various extractors. It may be possible to overstate extractor function but it's interesting to look at some designs that took it very seriously. Certainly in the case of semi-autos, one must.

In the case of Marlins, and lever guns in general, there is likely a point at which improved extractors can't offer much advantage. These actions only offer so much leverage for extraction. I for one will put a rod down the bore to dislodge a stuck case before I exert enough force to cause a 336 extractor to fail. Then again, if one didn't have that option, it would be nice to have a more robust extractor to ensure the job gets done. To be honest, I've been so wrapped up in the 1894 design, which is far more problematic, that I've barely considered improvements to the 336/1895 extractor.

In the case of the 1894 I was up against significant constraints--namely, the nature of the existing extractor tunnel in the bolt--that shaped design decisions. But I'm pleased to say that one of the more important improvements I made was moving the pivot of the extractor much closer to the vector line. Combined with seriously more robust construction, ours is a bristling bad**s next to the factory "bobby pin" part. No case left behind.
 
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Discussion Starter #7
Adam did you get the pictures of the bolt face on my 500?

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I did. Hopefully your builder finally got the rifle sorted out?
 

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Looking forward to ordering one of those babies for my CL, to start with. (32-20) It's the 'hitchy'ist" of my 94's, and would probably be benefited the most. Then probably the 44's, and maybe the .357, although it's pretty smooth now.

Congratulations on seeing a dream become a reality! (once again) :biggrin:
 
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Discussion Starter #10
Looking forward to ordering one of those babies for my CL, to start with. (32-20) It's the 'hitchy'ist" of my 94's, and would probably be benefited the most. Then probably the 44's, and maybe the .357, although it's pretty smooth now.

Congratulations on seeing a dream become a reality! (once again) :biggrin:
Thanks Kraynky. The first production CL claws are just starting to come off the machine now. It would be nice to stop dreaming of extractors for awhile, but unfortunately I'm not quite done. I still have to make one for the post 2015 models. Remington changed the 1894 bolt face design in 2015, lowering the position of the extractor claw, but they didn't lower the position of the extractor cut in the breech. So our claw, being much taller and beefier than the factory unit, won't let the bolt shut. Thanks Obama...
 

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Oh-got me. I thought we were talking about "getting on the chopper!". I could've talked about that "extraction point" scenario in depth.

That aside, when I do acquire an 1894, I look forward to swapping out the extractor for one of yours.

Yup- you got me.
 
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Discussion Starter #12
After months of R&D, and much testing, we've decided to do a beta test before officially launching the new extractors. We're confident in the design at this point, but frankly, we've seen so many unusual variations in the 1894 rifles themselves that we want to be doubly sure we aren't going to have fitment issues once parts start shipping. Why, just yesterday we came across an 1894CL bolt with an entirely non-standard configuration.

Given the vagaries of mass production, we may never satisfy every odd variation, but we're doing our best. Fact is, unlike the factory "bobby pin" extractor, which itself shows quite a bit of tolerance variation, our extractors are not a one-size-fits-all part. They are designed to be a close fit in their respective bolts to help eliminate functional inconsistencies. That makes our job harder.

But I'll say this for the record: RPP is not in the business of selling cheap, disappointing gizmos. Plenty of companies have made million$ doing so, but that will never be us. We design parts when we see a need, and we don't sell them unless they work.

To that end, we have asked four MO members to help us beta test the production-ready parts before we launch. The participants were selected based on their keen interest in the OP. Please don't take offense if you weren't asked. If necessary we may ask for additional volunteers.

This process will push the launch another couple of weeks, but given the importance of this part, we are in no hurry if it means we get off on the wrong foot. Please be patient and recognize that this delay is part of our process for insuring that you get the best possible product. Thank you.

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Adam will this extractor be beneficial to any of the rimless pistol caliber conversions you have done such as my 45?
 
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Discussion Starter #15
Adam will this extractor be beneficial to any of the rimless pistol caliber conversions you have done such as my 45?
Good of you to ask Bryan. Our pistol caliber conversions were an important driver in the development of this extractor design. Fact is, those conversions are such a bear to tune properly, that we wanted a drop in part to take the place of the finicky factory part. Plenty of R&D went toward getting the short strokes outfitted with a predictable extractor. All of our rimless pistol conversions now come standard with our new extractor design. The extractor for these rifles is its own unique design to handle the smaller rim sizes.

Not only that, but each of our short strokes is also set up as a controlled round feed (CRF) as well. This is a twist on the "Widdermatic" angle feed that some SASS guys have come to love. Widder was a pioneer in developing his angle feed system, which prevented cartridge roll-off, but in our experience they were pretty difficult to get running right because of the steep feed angle. We maintain a shallower feed angle, but still achieve exceptional reliability at SASS speeds by capturing the case rim before there is any chance for the cartridge to move out of alignment with the chamber, never mind rolling off. As a result our conversions are more predictable in tuning, slicker than ever, and ready to run at warp speed.

We've been beta testing the CRF extractor with a SASS shooter who runs two--soon to be three--of our custom short strokes. As of now, it appears we've got them well sorted.

AD
 
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Discussion Starter #16
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Discussion Starter #17
DRUM ROLL PLEASE!! THE RANGER POINT M/94 EXTRACTOR CLAWS ARE NOW AVAILABLE ON THE WEBSITE.
Extraction Team - Ranger Point Store

* During testing of the extractors, we learned that over the years, Marlin and Remington made various changes to the Marlin 1894's bolt shaft size and horizontal position. As such, this required us to design and machine six versions of our extractor claw - five of which we sell on the website - and one made specifically for semi-auto pistol ammo & control feed that we use exclusively in all of our Marlin 1894 pistol caliber, short stroke conversions (.9mm, .10mm, .357SIG, .40 S&W, .45ACP, or .44 RIPSAW).

WE HAVE PHOTOS OF ALL FIVE BOLT VARIATIONS ON THE WEBSITE SO THAT YOU CAN COMPARE YOUR BOLT TO THE PHOTOS TO DETERMINE WHICH ONE THAT YOU NEED.

Thanks again to all of our testers and to the entire MOF community for your continued support.

Adam
 
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Discussion Starter #19
Got mine ordered!
Thanks M1! Good thing we made a bunch of these things. You mighta cleaned us out. This promises to be our strongest product launch yet.
 

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Adam I may have another bolt face for you. I'll send a picture of it to your cell phone.
 
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