Photos of Failed 76/760 Extractors?

[Jim in Texas]

In my earlier post about MK760 extractors, Don mentioned that he might be able to provide photos of a couple of broken extractors.  Does anyone else have photos they can share of extractors that have broken, or worn out, or otherwise failed?  I think they would be helpful for hobbyists trying to make their own extractor, as well as for people considering making replacement parts commercially.  Thanks.

 

[Don.]

Hey Jim!  Sorry about that, life has kinda kicked me in the sack recently.  If I haven’t posted by Friday evening, feel free to remind me through email and I’ll get it done.  I also need to take some measurements for Navgunner on Sturm for the bolts and receiver I have.

[Don.]

Thanks for getting a fire lit under my arse, Jim.  The good news is that I got a picture and remembered a project I started and back-burnered years ago.  The bad news is that the damage is gone.  
Despite my crappy memory, I can say that the extractor that came with my 760 was missing the left portion closest to the extractor causing intermittent failures to extract (bottom).  

The top two are my Dremel creations that failed by shearing the claw off completely.  I don’t know what type of scrap steel that I used.  I do know that I used my Kasenit when heat treating them and it must have been too brittle as the claws completely sheared off.

As you can see, I hit them with the wire feed, started and then stopped when Scott Andrey came through with my order.  Again, I apologize for misremembering where I left off.  Looks like I need to go through the parts hoard and finish some of my projects.

BTW, I’m also interested in one of your sears.  I also have two more of Scott’s extractors if you’re planning on recreating them.  I’m still running one that I got from him initially and it has yet to fail.

[Jim in Texas]

Don:

Thanks.  This is rather impressive work for a Dremel.  The sheared-off hook is what I was trying to avoid by not hardening my experimental extractor after I did the machine work.  Do you remember if your Scott Andrey extractors are the "long" or "short" version?  

Jim

 

[Rekraps]

On 5/17/2025 at 11:27 PM, Don. said:

Thanks for getting a fire lit under my arse, Jim.  The good news is that I got a picture and remembered a project I started and back-burnered years ago.  The bad news is that the damage is gone.  
Despite my crappy memory, I can say that the extractor that came with my 760 was missing the left portion closest to the extractor causing intermittent failures to extract (bottom).  

The top two are my Dremel creations that failed by shearing the claw off completely.  I don’t know what type of scrap steel that I used.  I do know that I used my Kasenit when heat treating them and it must have been too brittle as the claws completely sheared off.

As you can see, I hit them with the wire feed, started and then stopped when Scott Andrey came through with my order.  Again, I apologize for misremembering where I left off.  Looks like I need to go through the parts hoard and finish some of my projects.

BTW, I’m also interested in one of your sears.  I also have two more of Scott’s extractors if you’re planning on recreating them.  I’m still running one that I got from him initially and it has yet to fail.

I have three of Andrey's extractors, they are "longer" than the OEM versions, and fit only his bolts.

[Jim in Texas]

I have no personal knowledge regarding either Scott's bolts or extractors, but I just checked his website and under Details for his full auto bolt, it says:

“Our bolts are made of 4140 steel, properly heat treated, and produced in limited production runs.  They feature the "curved" transition from bolt nose to bolt body as these have been found to work in any Smith 76 or MK 760 in which they have been tried.  They are complete with extractor (they use the 'short' extractor) and each bolt is function fired in the shop gun prior to being bead blasted and parkerized.”

Could he have changed the design at some point - perhaps to an extra-long extractor?  Under Details for full auto extractors, Scott references short extractors for bolts with a curved transition and long extractors for bolts with a flat transition.  If Don can provide us with additional information about the extractors he got from Scott, it may help to shed some light on the situation.

[Don.]

Sorry for the drive-by posting that I do.  Here’s what I have that’s not installed.  They are the long variety and are marked 1 in on one side, L on the other.

Maybe my order took longer than I remembered, lol!

[Don.]

I’m running them in both of my factory bolts, as the machining is identical on the exposed portions.  These were replaced circa 2010ish?  I haven’t had a failure since installing them.

Edited May 20 by Don.

[Jim in Texas]

Don:

Thanks for the great photos.  In the photo of the installed extractors, it looks like the extractor on the right protrudes past the bolt nose.  Is that correct?  If it is, does the extractor protrude about 0.025”?  If so, the bolt on the right may be one of the bolts that Scott says should use a “short” extractor.  I think we we would all like to hear more about that bolt.  Which manufacturer?  Earlier or later than your bolt that takes the long extractor?  Etc.

Edited May 22 by Jim in Texas

[Rekraps]

2 hours ago, Jim in Texas said:

Don:

Thanks for the great photos.  In the photo of the installed extractors, it looks like the extractor on the right protrudes past the bolt nose.  Is that correct?  If it is, does the extractor protrude about 0.035”?  If so, the bolt on the right may be one of the bolts that Scott says should use a “short” extractor.  I think we we would all like to hear more about that bolt.  Which manufacturer?  Earlier or later than your bolt that takes the long extractor?  Etc.

I have one of Scott Andrey's bolts, w/his proprietary extractor. When he sent me two extra extractors, I tried to fit them into an OEM bolt and it was a no go. I can take pics of both bolts and extractors (i have extra of each) if you guys need them.

[Jim in Texas]

Rekraps:

Yes, please.  Now that Scott is out of the business, I would like to see his knowledge and designs preserved for future generations.  In particular, I would like to know what he changed from the original extractor design.  I would also like very much to see how he beefed-up the nose of his proprietary bolts.

Thanks

 

[Don.]

Hey boss!  I’m back on the road again and won’t be back home until the weekend.  I’ll get a measurement then.  I can say that despite the protruding, the bolt assembly functions flawlessly.

It’s an MKA factory bolt that I bought with a complete part set back in the day.  I don’t know the pedigree of the SMG it came from unfortunately.  It is one of the extractors that was from Scott.

[Rekraps]

11 hours ago, Don. said:

Hey boss!  I’m back on the road again and won’t be back home until the weekend.  I’ll get a measurement then.  I can say that despite the protruding, the bolt assembly functions flawlessly.

It’s an MKA factory bolt that I bought with a complete part set back in the day.  I don’t know the pedigree of the SMG it came from unfortunately.  It is one of the extractors that was from Scott.

The gun runs with the protruding extractor? My issue was that the alignment of the mounting hole was different between the Andrey Bolt/extractor and OEM, just a tad but enough so that the two were not interchangeable.

[Rekraps]

11 hours ago, Jim in Texas said:

 

Rekraps:

Yes, please.  Now that Scott is out of the business, I would like to see his knowledge and designs preserved for future generations.  In particular, I would like to know what he changed from the original extractor design.  I would also like very much to see how he beefed-up the nose of his proprietary bolts.

Thanks

 

Will do. It will be this weekend as I'm traveling the rest of the week. 

[Rekraps]

And IMO, the Andrey bolt is leaps better in design. Very much beefed up nose area, and a modified sear stop (not sure I like this mod, its a curved recess vs flat like the OEM)

[Don.]

12 hours ago, Rekraps said:

The gun runs with the protruding extractor? My issue was that the alignment of the mounting hole was different between the Andrey Bolt/extractor and OEM, just a tad but enough so that the two were not interchangeable.

Runs without a hitch, semi and full.  To be honest, I never noticed it until I saw the picture, LOL!  There’s a pretty generous pocket in the trunnion for the extractor to do its thing.

 I know it works because I broke the original bolt with a 7,62x25 conversion I made and was running.  I sent it to Richard at BWE and he rebuilt the lower lip that the x25 broke off.  It’s unfortunate that he passed, as he was starting to venture into the 76/760 parts realm.

 

[Rekraps]

10 hours ago, Don. said:

Runs without a hitch, semi and full.  To be honest, I never noticed it until I saw the picture, LOL!  There’s a pretty generous pocket in the trunnion for the extractor to do its thing.

 I know it works because I broke the original bolt with a 7,62x25 conversion I made and was running.  I sent it to Richard at BWE and he rebuilt the lower lip that the x25 broke off.  It’s unfortunate that he passed, as he was starting to venture into the 76/760 parts realm.

 

No kidding. In addition to Andrey, Richard (BWE) was the source of many of my spare 76 parts. 

[Don.]

I’ll be screwing around with guns in the car hole tomorrow.  I’ll write a reminder to get a measurement on the protruding extractor.

Edited May 26 by Don.

[Don.]

According to the chinese dial caliper, she sticks out 0.052”.  I can get it out in a week or two and get a proof of life clip.

[Rekraps]

On 5/20/2025 at 8:59 PM, Jim in Texas said:

 

Rekraps:

Yes, please.  Now that Scott is out of the business, I would like to see his knowledge and designs preserved for future generations.  In particular, I would like to know what he changed from the original extractor design.  I would also like very much to see how he beefed-up the nose of his proprietary bolts.

Thanks

 

Finally got to it. In all pictures, the Andrey parts are furthest away. Note that the Andrey bolt is significantly more robust, particularly the bolt face lower lip. The extractors are also different as you can see. The bolt itself is dimensionally identical to the OEM bolt, it's just the extractor and bolt face that are different.

[Jim in Texas]

Rekraps:

Thanks for the photos.  They raise a couple of questions.

1.  The lower lip on your OEM bolt is indeed rather thin.  Which manufacturer and what vintage is that bolt?

2.  It looks like there are markings on your SA Machine extractor, but I cannot make them out.  What are those markings?

Jim

 

Edited May 26 by Jim in Texas

[Rekraps]

46 minutes ago, Jim in Texas said:

Rekraps:

Thanks for the photos.  They raise a couple of questions.

1.  The lower lip on your OEM bolt is indeed rather thin.  Which manufacturer and what vintage is that bolt?

2.  It looks like there are markings on your SA Machine extractor, but I cannot make them out.  What are those markings?

Jim

 

Hey Jim, the OEM bolt is an original S&W, and all of my Andrey extractors have a stamp. I put them up  but I believe it is 11 Y. 
I spoke with Scott a few years ago and he told me that his bolts were intentionally made more robust to address the OEM deficiencies.  He said that the 76’s, like the M3’s were not intended to be long term usage guns, and they were designed for short term use then destruction. I see that now when I compare them to the M1, Thompson or M14. 

[Rekraps]

53 minutes ago, Jim in Texas said:

Rekraps:

Thanks for the photos.  They raise a couple of questions.

1.  The lower lip on your OEM bolt is indeed rather thin.  Which manufacturer and what vintage is that bolt?

2.  It looks like there are markings on your SA Machine extractor, but I cannot make them out.  What are those markings?

Jim

 

Previously I had shipped one of  the S&W bolts to Andrewski to take a look at and he too said the lower lip was the Achilles heel of the bolt design (and the trigger bar of course).  He said he had repaired many. 

[Jim in Texas]

Rekraps:

Interesting information.  I wonder if the thin lower lip is a characteristic of early S&W guns.  My experience is with Irvine MK760s, and they all have a more robust lower lip, like on your SA Machine bolt.  Perhaps S&W started out with the thin lip and increased its thickness in later guns.  Then, when MK Arms purchased the rights from S&W, they used the later and heavier design for their bolts.  Is your S&W bolt from an early or a late gun?

On the extractors, your SA Machine extractors look like they might be his “Short” extractors.  Using Scott’s terminology, “Long” and “Short” do not refer to the overall length of the extractor, but only to the distance between the centerline of the pivot pin and the working face of the extractor hook, and they only differ by 0.025” in that dimension.  That could keep a “Short” extractor from working in a “Long” bolt, and may be enough to prevent it from even being installed.

A “Short” extractor on your SA Machine bolt would be consistent with Scott’s description of his improved bolt on his website.  Don’s photos of the “Long” extractors show “11N” on one side and “L” on the other.  I wonder what marking, if any, your SA Machine extractors have on the other side.

All interesting stuff.

 

[Rekraps]

I really can't comment on the OEM bolts other than to say my SN on one 76 is U544 and the second is U1479. Andrewski has the U1479 bolt now for some work, but when it comes back I'll look to see if the lower lip is reinforced. As to the extractors, next time I get them out I'll look more closely at the markings. I'm just happy that Scott sent me two replacement extractors, otherwise I'd be up the creek.