What is name of the part of a model 70 extractor just behind the blade that rides in the groove on the bolt?

And...does anyone know if there are any extractors made that have an oversized (see part described above) to eliminate some excessive movement?

Thanks

It is some sort of gas block, and is called a gas block, used only on post 64 CRF guns. Lawyer piece; totally useless.
No.

its on the extractor itself. Not the gas block that clips under the collar, that's opposite the extractor. It would be the part on a mauser extractor that would fit the deep undercut on the bolt.

It has no name. Bolt/Extractor groove riding tongue. A new aftermarket extractor might be tighter than a factory one; check with Brownells.

Are you trying to tighten up the extractor for better extraction, or is it too tight holding a case during extrraction?

Is it loose and the extractor moves front to back in line with the bolt?

If I am understanding the part that you are talking about, relieving it will tighten the grip on the case, and relieving the extractor hook will loosen the grip.

Not sure if I am interpreting your query right, though.

Jeremy

farbedo:

The extractor does move in line with the bolt and bit, and this will on a very infrequent occasion, as the bolt closed, allow the rim of the brass to get pinched a teeny bit between the back of the extractor blade and the little shoulder on the front of the bolt(it only takes a small amount more pressure to close the bolt), but this will take a very small sliver off the edge of the rim. I measured the groove that this 'tongue' rides in on my other two Model 70s and they are about .018 narrower, and this allows the movement.

It's not a huge thing since this is not a DG gun, but it's an occasional hiccup that annoys me. I was surprised to see that lifting the bolt off the face, there is enough room to see air underneath it and the little shoulder on the bolt face.

Top arrow points to area rim gets pinched, left arrow is the groove thats a little fat.

Sounds like he is referding to the "extractor collar"

No he means the tongue that rides in the bolt groove; it looks like to me that your extractor lip is not finished. It looks rough and dull. I see casting flash on it too. And it seems to be that they forgot to grind it smooth; I see a little square piece on the lip angle that should not be there. I think if you take it off and smooth it, and make the lip a bit sharper, your problem will go away. Use a fine half round file and stones. I would use a belt sander.

dpcd: You noticed something I thought about too...the very edge of the extractor blade is squared off, and in fact will leave marks on the brass, perhaps it's catching on occasion. I have some very fine jeweler's files I can use to clean things up and then polish with 400 or 600 grit to make the lip sharper without messing with the back edge of the extractor that actually contacts the rim.

Buy a new extractor.

Fix the one you have. I will do it for you if you want me to.

Thanks for the photo. That helps. Slicking it up as suggested should help.

To me, though, it looks like there is excess clearance between the bolt face and the extractor blade.

Have you tried swapping extractors with one of your other M70's just to see how the fitup is? How does the gap between the blade and bolt face compare with your other rifles?

If they all look the same, probably just polish it and leave it be. If this extractor has more clearance, I would be inclined to get a new one from Williams, or Wisner.

All of the suggestions are worth a try.

Jeremy

Jeremy: Good eyes....as I said, I was surprised that there was enough room to see light under the case when lifted off the bolt face. I've fitted the others but cant do a test at they are standard and this is a magnum bolt face.

I've smoothed everything out and will do some more testing later tonight. If I have any issues, I'll post more pics... as I say, It's not a HUGE, problem, just something that shouldn't happen but does every now and then.

Thanks!

Here is a series of photos of my Mauser bolt face, opened up for the 404 Jeffery cartridge. This rifle is the smoothest feeding controlled round rifle I have ever had or tried. The 404 cartridge will clip under the extractor and hang on the bolt face without support when the bolt is held horizontally out of the rifle.
In use the big 404 cartridges pop up from the magazine, the case rim clipping in under the extractor, and then feed perfectly into the chamber even with blunt nosed cast bullets which are not always the easiest to get to feed well.

The rifle did not do this when I first bought it having been just converted in Africa to the 404 cartridge from the original .423 Mauser. It did feed from the magazine but scratched hell out of the cases and needed a good hard shove on the bolt handle to feed. Just stoning off the lower edge of the extractor hook cured this instantly, nothing more done.

Tell me this; are your firing pin indents centered? I have a theory that is unrelated to the extractor, which could be an issue. Basically, I don't think the extractor is the problem.

BaxterB, if you look at the last photo in the series I have posted here you can see that the underside of the extractor blade does not sit back hard against the case rim but actually holds the case on the bolt face just with the sideways pressure of the crescent shaped extractor blade. There is a small gap between the head of the case and the bolt face which will of course be taken up when the cartridge is chambered. The case rim cannot get caught between the blade and the raised protrusion on the outer edge of the bolt face as the underside of the extractor blade tapers towards the extractor body. You can see this taper in the photo I speak of and even the third photo in the series shows this taper on the underside of the blade.

Note that there is very little protrusion of the extractor nose when measured from the bolt face.

The extractor on your M70 appears to have the blade way too forward of the bolt face and it appears to have no taper on the underside of the blade to prevent the case head from moving sideways and jamming as you describe. This could happen occasionally with a case having a deeper extractor groove than others.

Also it appears the extractor blade, sitting so far from the bolt face, must ride up onto the forward taper of the case extractor groove as the cartridge is chambered and the case head is pushed back onto the bolt face. This surely must make for harder bolt closure? Presumably there is enough clearance for the extractor nose in the breach face otherwise it would be impossible to close the bolt with that particular extractor?

quote:

Originally posted by Duane Wiebe (CG&R):
Eagle: Actually, you've ground away about 25% of the hook. There's another way..I'll post photos on Monday. By the way, will this single load?

It's a long, long time ago when I stoned off the bottom sharp edge of the hook and from memory only used a couple of swipes with a fine wet stone. The hook may have already had some work on it. I have not attempted, or wish to attempt, to push feed a cartridge so I cannot answer your question Duane, though it looks like the extractor should slip over a rim if push fed. All I know is that the rifle has one of the easiest magazines to charge and it feeds and ejects like a dream. The magazine spring is not heavy so the rounds clip in without any great exertion and there's plenty of room despite the charger guides not being not touched when the action was opened up. Holds 3 and a half so can feed the 4th into the chamber over a mag of 3.

I am sure the rifle had not been used in it's .404 chambering when I got it as it just did not feed well and the POI for the .404 ammo was about a foot high i.e. had not been re-sighted from when the rifle was a 10.75x68.

Well, after reshaping the extractor and doing some polishing that Winchester should have done, I'm happy with the progress. There may be other things going on as dpcd and I have talked about via PMs, but I'm gonna roll with what I have with the sincere thanks from all those who gave advice. I'd say the problem is 90% solved, and that's damn good for a guy with jeweler's files, some 400 grit paper, and a few brain cells left...

Eagle27, your mention of the extractor blade hitting the brass made me do some more work that helped even more, thank you.

quote:

Originally posted by Duane Wiebe (CG&R):

quote:

Originally posted by eagle27:

quote:

Originally posted by Duane Wiebe (CG&R):
Eagle: Actually, you've ground away about 25% of the hook. There's another way..I'll post photos on Monday. By the way, will this single load?

It's a long, long time ago when I stoned off the bottom sharp edge of the hook and from memory only used a couple of swipes with a fine wet stone. The hook may have already had some work on it. I have not attempted, or wish to attempt, to push feed a cartridge so I cannot answer your question Duane, though it looks like the extractor should slip over a rim if push fed. All I know is that the rifle has one of the easiest magazines to charge and it feeds and ejects like a dream. The magazine spring is not heavy so the rounds clip in without any great exertion and there's plenty of room despite the charger guides not being not touched when the action was opened up. Holds 3 and a half so can feed the 4th into the chamber over a mag of 3.

I am sure the rifle had not been used in it's .404 chambering when I got it as it just did not feed well and the POI for the .404 ammo was about a foot high i.e. had not been re-sighted from when the rifle was a 10.75x68.

Good of you to point out the magazine spring. I too, have found that some of these after market "magnum" springs are just too damn stiff

An hour in the kitchen over at 550 F al;most always results in smoother feeding.

Was going to ask how you would get a softer spring then read your last sentence, very interesting. Yes my magazine spring is surprisingly soft but has no trouble lifting the rounds up and does make for quick and easy re-stacking even being a leftie; the thumb cut really helps out here, custom made for lefties

My Brno 600ZKK is a real bitch to load the magazine with a very heavy spring. I would hate to have this in a dangerous game gun.

quote:

Originally posted by Duane Wiebe (CG&R):
Well...my photos got misakenly put in another post...same title "Parts of an extractor"

Had a look at the photos of that nice fitting Mauser extractor , thanks for posting.

Baxter B,
That extractor does sit too far ahead of the bolt face and the problem is with the bolt; not the extractor. Winchester (Browning Arms Co) does not even acknowledge this. Compare the dimension and location of the groove to a pre-64 bolt and the difference is obvious though apparently, not so obvious to a Winchester engineer. Regards, Bill

Bill, I agree with you 100%. That's why in my first post I asked if there were extractors available with an oversized 'tongue' so that final fitting can be done to be able to vary the space between the bolt face and extractor blade. I called Williams and they said no. HE also told me he hasn't made OEM extractors for WInchester in two years, interesting. I think it would be straight forward to make one as such, but seems there's no interest.

I have done as you say and looked at pre-64's and the tolerances are much tighter there. Frustrating that technology has advanced, yet quality has suffered.

Hmm...will do, thanks