Bolt struggling to close
- Thread starter MichaelD
- Start date
MichaelD
Active member
Acidently posted without typing.
Hi Everyone as you can se in this image the k98k bolt struggles to close when feeding a round, it can be forced a little and will close and lock.. it has no issue closing when there is no round to chamber and the bolt is hitting at the top of the chamber.. anyone know why this happens and a remedy
Muncher 1953
Senior Member
look at the extractor claw first, might be bent.
details or photos of the ammo you’re using & face of bolt showing extractor claw may help. it sounds like the extractor isn’t engaging the cartridge rim (or not fully/properly) forcing the bolt high in its ‘ways’. because the problem appears before the cartridge is chambered, I don’t think it’s a ‘cartridge overall length’ issue. is it brand name ammo? or converted from another caliber? (like .30-06)
details or photos of the ammo you’re using & face of bolt showing extractor claw may help. it sounds like the extractor isn’t engaging the cartridge rim (or not fully/properly) forcing the bolt high in its ‘ways’. because the problem appears before the cartridge is chambered, I don’t think it’s a ‘cartridge overall length’ issue. is it brand name ammo? or converted from another caliber? (like .30-06)
Most Mausers will NOT allow the bolt to close if the cartridge is chambered BEFORE the bolt is pushed forward.
When the cartridges are placed in the magazine, feeding will be OK, as the cartridge rim slides up the face of the bolt, BEHIND the extractor claw.
NOTE: Some Model 70 Winchesters will also “behave” the same way.
When the cartridges are placed in the magazine, feeding will be OK, as the cartridge rim slides up the face of the bolt, BEHIND the extractor claw.
NOTE: Some Model 70 Winchesters will also “behave” the same way.
MichaelD
Active member
Some new info when playing around with it a little now, is it possible to be a magazine issue?
If i keep the magazine depressed i manually feed the round in with my hand, as long as i keep the magazine down the bolt will feed and chamber the round perfectly.
AS for ammo this specific round is PPU not sure which grain just some left over rounds, I have another 98k that eets this ammo no problem.
MichaelD
Active member
Thx for the response but I am feeding this rifle out of its magazine.
I replied to the other fellow as well, whats strange to me, if i remove the magazine and insert the round a little by hand the bolt feeds the round fine the rest of the way without catching on the top?
Can the magazine be influencing the bolt?
moconfed
Senior Member
What?
MichaelD
Active member
Mauser Feeding - Google Drive
drive.google.com
If you dont mind I made a drive folder with 3 videos on it showing where the bolt is snagging, and also that after intial feed it no longer has a problem feeding the cartridge
MichaelD
Active member
If
If i keep the feed ramp down with my hand and put the bullet into the chamber with my hand, the bolt does not have a issue closing.
moconfed
Senior Member
I believe you're talking about the follower. The feed ramp is part of the receiver.
If you are able to open the bolt fully, insert a cartridge into the receiver, and then close the bolt, you have a problem. Post a picture of your bolt showing the face. Sounds like you could have a damaged extractor.
MichaelD
Active member
https://drive.google.com/drive/folders/1YyTgRkLrIkRFaVk5hKd_zZmqJr0JYu0j
Put it onto drive as i have trouble uoloadi g images on this site.. there is videos on there showing what i mean aswell
MichaelD
Active member
To me it just appears as if the bolt is riding high when I insert a round, byt i cant determine why.
GEM
Senior Member
I looked at the videos closely. Based on what you show I don't see any contributing factors from the follower and spring. I can't tell from the picture but I suspect this is a bolt mismatched rifle. (Also I see that it is drilled and tapped and wood relieved for a receiver sight.)
Some speculation: I think there is something going on with the extractor bring loose. It is possible that the extractor has lost tension and is not held tightly against the bolt body. When a round is fed up from the magazine into the bolt face the end of the loose extractor is pushed up and impacts the receiver upon closing.
To check this try holding the extractor tight agsinst the bolt body while closing the bolt. You can also try a bolt from another rifle or another extractor. A possible fix is to increase the tightness of the extractor by removing the extractor. Place the ends on two pieces of wood and press gradually with you thumb to increase the curvature along the length. Probably only requires a slight deformation to increase the spring tension.
Some speculation: I think there is something going on with the extractor bring loose. It is possible that the extractor has lost tension and is not held tightly against the bolt body. When a round is fed up from the magazine into the bolt face the end of the loose extractor is pushed up and impacts the receiver upon closing.
To check this try holding the extractor tight agsinst the bolt body while closing the bolt. You can also try a bolt from another rifle or another extractor. A possible fix is to increase the tightness of the extractor by removing the extractor. Place the ends on two pieces of wood and press gradually with you thumb to increase the curvature along the length. Probably only requires a slight deformation to increase the spring tension.
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MichaelD
Active member
It is not a bolt mismatch, she is an all matching rifle, there is a post about her on this form haha, only thing not matching is the saftey which I think must be an repair because it isnt serialized
I will see if i can figure anything out with the extractor, but she shoots fine and extracts nicely.
MichaelD
Active member
Oky, i have a finding, and i think you might be spot on, if I try and chamber a round and i keep some pressure on the tab where the extractor is actually attached to the bolt it closes smoothly.
Is there a way to tighten the extractor back to the body of the of the bolt.. i will try and make videos and post them on the drive to show what i am talking about.
so as the round is picked up out of the magazine, it just slightly pushes the extractor up forcing it to hit the reciever, thus why by eliminating the magazine I also dont have the extractor issue...
So now i have a matching extractor thats just a little too loose and i cant really do anything about it?
Mauser Feeding - Google Drive
drive.google.com
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GEM
Senior Member
This is easily repaired. See attached pictures.
Picture titled Extractor 1 shows the curved profile of the extractor. The curvature applies pressure on the two bearing surfaces on the ends of the extractor as the extractor is assembled to the attaching lug on the bolt collar. Over time (80+ years), the extractor has "flattened" and the fit has loosened as it is under constant compression when assembled. If the extractor is loose fitting on the bolt (rattles) or can be easily pushed so as to not be parallel to the axis of the bolt, then those are a clear indication of this diagnosis.
The picture labeled Extractor 2 shows how to restore the curvature to the extractor to increase the pressure on the bearing surfaces. Firmly press the center of the extractor mounted between two wood blocks to deform it back to a curved shape. I recommend wood blocks so as to not damage the metal surface. Likely will not take a great deal of deformation to restore the curve. Probably no more that 1/16" will be required. The desired outcome is for the two bearing surfaces to firmly contact the bolt body. This may take some trial and error.
Note that this part is tempered spring steel and is pretty tough, so damage is unlikely. But if it is overbent it can fracture. That is why I recommend the "softly, softly" thumb pressure approach over putting it in a vise or some other "brute force" method.
If you need bolt disassembly/assembly instructions, there are plenty of YouTube videos.
Picture titled Extractor 1 shows the curved profile of the extractor. The curvature applies pressure on the two bearing surfaces on the ends of the extractor as the extractor is assembled to the attaching lug on the bolt collar. Over time (80+ years), the extractor has "flattened" and the fit has loosened as it is under constant compression when assembled. If the extractor is loose fitting on the bolt (rattles) or can be easily pushed so as to not be parallel to the axis of the bolt, then those are a clear indication of this diagnosis.
The picture labeled Extractor 2 shows how to restore the curvature to the extractor to increase the pressure on the bearing surfaces. Firmly press the center of the extractor mounted between two wood blocks to deform it back to a curved shape. I recommend wood blocks so as to not damage the metal surface. Likely will not take a great deal of deformation to restore the curve. Probably no more that 1/16" will be required. The desired outcome is for the two bearing surfaces to firmly contact the bolt body. This may take some trial and error.
Note that this part is tempered spring steel and is pretty tough, so damage is unlikely. But if it is overbent it can fracture. That is why I recommend the "softly, softly" thumb pressure approach over putting it in a vise or some other "brute force" method.
If you need bolt disassembly/assembly instructions, there are plenty of YouTube videos.
Attachments
whcoyote
Well-known member
The extractor, in the first photo, looks pretty straight to me. If it was sprung you could see an inward bow easily in the photo.
Something is forcing the end of the extractor upward when the bolt moves forward. This could be: (a) something in the bottom of the extractor groove, or a deformation in the lower lip of the extractor groove, or (b) a burr or ding on the inside of the extractor claw that prevents the cartridge case rim from sliding all the way up the bolt face. The case rim catches on this burr and lifts the extractor up as you chamber the cartridge. (c) dirt or a deformation in the top of the extractor groove in the receiver bridge, forcing the tail of the extractor down upon bolt forward movement, pivoting the claw-end upward.
May be other things
In the photo it looks like the extractor is too far forward on the bolt, possibly from wear - but this could be an illusion from the perspective of the parts in the photo. BUT, if this is so, perhaps the extractor claw is too far forward and is engaging the case body ahead of the extractor groove, forcing it up and causing it to bind.
The extractor must fit snugly, even tightly, on the collar and the collar must rotate freely in its groove on the bolt.
Something is forcing the end of the extractor upward when the bolt moves forward. This could be: (a) something in the bottom of the extractor groove, or a deformation in the lower lip of the extractor groove, or (b) a burr or ding on the inside of the extractor claw that prevents the cartridge case rim from sliding all the way up the bolt face. The case rim catches on this burr and lifts the extractor up as you chamber the cartridge. (c) dirt or a deformation in the top of the extractor groove in the receiver bridge, forcing the tail of the extractor down upon bolt forward movement, pivoting the claw-end upward.
May be other things
In the photo it looks like the extractor is too far forward on the bolt, possibly from wear - but this could be an illusion from the perspective of the parts in the photo. BUT, if this is so, perhaps the extractor claw is too far forward and is engaging the case body ahead of the extractor groove, forcing it up and causing it to bind.
The extractor must fit snugly, even tightly, on the collar and the collar must rotate freely in its groove on the bolt.