Extractor claw-related question.. kinda long

[bradh]

Hello,

I am having a bit of an extractor fitting issue. To put it simply, I'm new and I stink at this. I ordered a few extractors with the goal of teaching myself how to fit one, should I ever need to in the future.

I was able to fit a Cylinder and Slide extractor, good pressure between the extractor tensioning wall and ammunition case rim, without contact between the extractor claw and ammunition case bevel. The depth of the extractor claw measured 0.034 which I believe is within specs.

I celebrated with a beer!

For kicks, I tried the same procedure with an Ed Brown Hardcore. But, to get the extractor tensioning wall to contact the ammunition case rim, without the extractor claw riding up on the ammunition case bevel, I had to remove enough metal from the claw such that the final depth measured 0.027, which I believe is under the specs.
This happened with the second Ed Brown I apparently ruined as well.

I started playing with the EGW extractor, but figured I should stop; else I ruin another perfectly good piece of metal. On that note, the EGW looks to have a higher/deeper extractor claw, perhaps to allow more room for custom fitting? If I measured correctly, the depth of the extractor claw is around 0.050

Interestingly, the stock extractor grabs the case rim without the claw bearing on the case bevel, but the final depth of the extractor claw measured 0.030, which I believe is also under specs. I have not had problems with extraction thus far, just over 1000 rounds. This is a Norinco 1911 (new barrel fit by Springfield, slide lowered/tightened by peening/swaging frame rails down a bit.)

I’m calculating the dept of the extractor claw by “measuring the thickness of the extractor stem at the tip of the claw. Then, from the tensioning wall...the area that bears against the rim. Subtract. The difference is the depth of the claw,” as per 1911tuner’s advice.

Any idea why I could fit the Cylinder and Slide, but not the Ed Browns?

Thanks all!
Brad


edit: hmm.. I could get he Ed Brown to fit.. in a fit of madness, I had to reshaped the nose of the extractor, taking off a bunch of metal in the process, leaving an angle that matched that of the case bevel, right up to the extractor claw... kind alike a knife blade, which certainly did not look "right"...

[John]

:wl:

[bradh]

Got it.. I'll try to take some pictures and post them asap!

Sorry!

[niemi24s]

Hi Bradh

There are two schools of thought on the subject of contact between the extractor claw and the case bevel.

The JMB extractor design is shown in the U.S. Army blueprint in our Technical Issues section. This drawing and the dimensions are based on it. . .
http://i129.photobucket.com/albums/p232/niemi24s/P078290001e.jpg
. . . and was done just to make for easier "seeing".

When combined with the SAAMI specifications for the 45ACP case, the result is. . .
http://i129.photobucket.com/albums/p232/niemi24s/P1310003a.jpg
. . .in which the claw contacts the case bevel when the case head is against the breech face. They're drawn superimposed to show that the case will force the extractor outward 0.006" upon firing.

The first school of thought maintains the original design's OK and there's no need to be concerned over contact between the claw and the case bevel.

The second school of thought maintains the original design is not OK and contact between the claw and the case bevel must be eliminated in order to prevent claw breakage.

Is one school of thought right and the other wrong? Or, are they just different?

Thought I'd post this info just in case you might not have been aware of it.

Cheers

[auto45]

I can see a 'contact' mark on the brass, which I assume is the extractor touching the bevel.

The extractor is 45,000 rounds+, so either it doesn't matter, or contact is so light it's not stressing anything in my particular combination.

Don't know! :)

[log man]

bradh, The observation that you have made and shared with us should be taken note of. The situation is that the dimension from slide stop groove to breech face and the dimension of extractor groove to hook dimensions vary. This makes it difficult to obtain the optimum .075" dimension between breech face and inside of hook. I find that either you need a selection of extractors or the skill to weld a shim in the groove and file an equal amount off the other side of the extractor so as to move it from the rear. This works well as you get exactly what you want.

LOG

[bradh]

I took several pictures, but my camera can't resolve the image well enough to show what I am trying to describe. More likely, my camerawork needs work. :)

Regardless... thank you very much for the help. Your explanations are excellent. Now I can go to work without thinking I'm totally crazy.

Thank you kindly,
Brad

[bradh]

I realize now that a more careful use of the "search" function on this forum would have likely yielded the answers I was looking for. My apologies, I will be more careful in the future.

Thanks again,
Brad

[RickB]

One of the design changes in the new EGW HD extractor addresses the issue. The hook is closer to the breechface, by about .015", to alleviate the hook/bevel interference. I've measured the hook protrusion of a number of extractors, and in the one gun with which I have the most experience (the most different extractors), they typically protrude about .090". The EGW part is definitely an improvement in that department.

[bradh]

I measured the EGW extractor this morning.

The thickness of the extractor stem at the tip of the claw minus the thickness of the stem to the tensioning wall was 0.050, and I think that big number was due to the fact the stem-to-tensioning wall thinner than other extractors I measured.

So, even though the hook is 0.015 closer to the breech face, it still contacted the bevel, a lot. It could very well just be my pistol's innards are out of whack... probably so.

I fiddled with the locationg pat, bend the extractor a bit and acheived good pressure on the case rim, but I had to file the claw down until the depth of the claw approached 0.035

Now, the case is held snug against the tensioning wall of the extractor, and the claw just kisses the case bevel. Best I could do.

FYI.. boy, that EGW is tough to bend, one tough sucker. I doubt Superman could break it.



Brad

[bradh]

I measured the EGW extractor this morning.

The thickness of the extractor stem at the tip of the claw minus the thickness of the stem to the tensioning wall was 0.050, and I think that big number was due to the fact the stem-to-tensioning wall was thinner than other extractors I measured.

So, even though the hook is 0.015 closer to the breech face, it still contacted the bevel, a lot. It could very well just be my pistol's innards are out of whack... probably so.

I fiddled with the locationg pad, bend the extractor a bit and acheived good pressure on the case rim, but I had to file the claw down until the depth of the claw approached 0.035

Now, the case is held snug against the tensioning wall of the extractor, and the claw just kisses the case bevel. Best I could do.

FYI.. boy, that EGW is tough to bend, one tough sucker. I doubt Superman could break it.



Brad

[RickB]

.035" is within spec, right? The EGW HD extractor is essentially a "blank canvas" upon which the gunsmith can/must perform whatever magic is necessary. It would be like comparing an oversize, gunsmith-fit barrel to a drop-in. A lot of the bevels, and chamfers and reliefs that come on other extractors, must be added to the EGW part. I think you did it right.

[bradh]

Rick,

I think 0.035 would not upset JMB or 1911tuner. Now that you mention it, I like the fact that the EGW is not prepped. Gave me much more room to experiment and learn. Next time though, I think I'll practice on a cheaper extractor before going at it on a more expensive heavy duty.

Though frustrating, this sure is fun (learning about the 1911).

Wait till the master of the house (wife) finds out I just ordered another 1911.

I only have 1 and from what I have read on this forum, having only 1 is a sin. I'll have to explain to my wife that I'm no sinner. :)

Brad

[niemi24s]

.035" is within spec, right?
Not quite, if you're referring to the Ordnance Dept. spec of 0.030 + 0.004 inch.

The RCBS (SAAMI?) spec for case groove works out to 0.040 ± 0.005 inch. When combined, a max spec 0.034" claw will fit in a min spec 0.035" groove with 0.001" clearance and still allow the tensioning wall to bear on the rim.

FWIW, in a mid spec USGI M1911A1 the distance from the breech face to the claw ranges from 0.088 to 0.0805 inch depending on whether the extractor is fully forward or aftward in its tunnel.

Also FWIW, the 0.006" overlap shown in the second drawing in Post #4 is sort of an average. It ranges from 0.0074" with the extractor forward to 0.0037" with the extrctor aftward. The average rounds down to 0.006".

Disregarding any claw/bevel contact, the case rim pushes the extractor positioning/locating pad 0.0095" off the tunnel wall. Will an extra, say, 0.0074" of extractor travel harm the extractor? If the case ends up fully forward off the breech face with no claw/bevel contact will the case harm the extractor upon firing?

The answers to these depend upon which of the two schools of thought you're enrolled in. The debate between the two will no doubt continue for decades - lots of decades.

Cheers

[bradh]

I wasn't sure what that 0.030 + 0.004 inch was pointing to in the drawing, I'm fairly new to reading diagrams of that sort.

Thanks again for all the responses, much appreciated.

Now can anyone tell me how to tell my wife that I bought that new 1911?

Brad

[niemi24s]

. . . can anyone tell me how to tell my wife that I bought that new 1911?
Just say you got it for her! :)

[Jolly Rogers]

bradh, The observation that you have made and shared with us should be taken note of. The situation is that the dimension from slide stop groove to breech face and the dimension of extractor groove to hook dimensions vary. This makes it difficult to obtain the optimum .075" dimension between breech face and inside of hook. I find that either you need a selection of extractors or the skill to weld a shim in the groove and file an equal amount off the other side of the extractor so as to move it from the rear. This works well as you get exactly what you want.

LOG

Log man...very aptly put!
Joe

[bradh]

Niemi.. I'll try that!

If 1911tuner wanders by this post:

Do you happen to have a picture or description of how you contour the extractor hook so it does not contact the case bevel? What is the final claw depth you're aiming for with your methods?

Thanks!!!

Brad

[log man]

Niemi.. I'll try that!

If 1911tuner wanders by this post:

Do you happen to have a picture or description of how you contour the extractor hook so it does not contact the case bevel? What is the final claw depth you're aiming for with your methods?

Thanks!!!

Brad

With the case under the extractor and pressed against the breech face the extractor tip should not touch the case bevel. If it does, shape it at the same angle as the bevel so as to not weaken the hook more than necessary.

LOG

[Iron bottom]

Watch the lateral movement of an extractor when fitting also. If I remember correctly. .015-.025 outward movement of the hook has been recommended, with .025 being the max. As the extractor moves outward the angle of the hook in relation to the breechface changes. If starting with a neutral angle on the hook, any outward movement is going to make the angle negative. A positive hook on a new extractor is a much desired feature, in my opinion.

I like the new EGW extractor. Positive hook angle is a big plus. As another poster mentioned, it is hard to bend and I also removed a little from the nose and polished it to allow the hook to jump the rim a little easier. Haven't had any problems whatsoever.