Sticky bolt lift after firing - fixed

[Flyonline]

Having a little trouble with a sticky bolt lift, but only after firing (dry or on cartridge). I've stripped the firing pin, cleaned the inside of the bolt and the pin with both carbon remover, ran a pipe cleaner through the bolt housing and re-oiled and greased everything but still no dice.

It's only on the lift after firing, without firing it's smooth as butter cocking/de-cocking but when firing it takes maybe 50% more effort than it used to. It came on suddenly and it's enough to annoy me so I'd like to get rid of it if I can as well as remove the possibility of further damage. The only thing I can see is that the cocking assembly doesn't quite sit at the bottom of the cam when in the fired position (like maybe 1/2 mm or so) but I can't compare that with before as I never noticed.

Rifle is Howa 1500

Any ideas or things to look for?

Thanks

Steve

[Oldbloke]

"Come on suddenly".
"Only after firing".
Did you change ammo? Or change load?

Sounds like a pressure issue to me.

[deye243]

Have you lubed the cooking groove and cam not real terms but the only words I have for them .

[Oldbloke]

I believe oil in the chamber can cause that problem too.

[straightshooter]

Flyonline
deye243 is on the right track.
The whole issue is with the cocking cam.
You will have to dismantle the cocking assembly and carefully examine both camming surfaces.
There will be one of two possibilities, one is less likely than the other.
Firstly dismantle the cocking assembly and carefully examine both camming surfaces and look for any small dent or discontinuity in the shape near the beginning of the cam especially the cam on the bolt. The likely cause will be due to not completely closing the bolt to it's full extent. This will allow the nose on the cocking piece to impact the cam surface rather than land in the opening provided at the origin of the cocking cam.
The less likely culprit is incorrect hardening on either or both cam surfaces. If this is the case galling might be visible on the softer surface.

[Oldbloke]

My mistake. I just noticed "after firing (dry or on cartridge".
So, not related to ammo or oil in chamber.

[Flyonline]

"Come on suddenly".
"Only after firing".
Did you change ammo? Or change load?

Sounds like a pressure issue to me.

No change, I've looked at the last few rounds and can't find anything that makes me think of over pressure (not that I know anything )

IMG_4992.JPG (177.85 KiB) Viewed 2787 times

They all look like this.

Have you lubed the cooking groove and cam not real terms but the only words I have for them .

On the bolt yes, not the grooves on the rifle though. It's sticky the whole way up, not like it's jumping out of a groove and then free just like it's stuck in honey the whole way. Unfired, smoooooth as

Flyonline
deye243 is on the right track.
The whole issue is with the cocking cam.
You will have to dismantle the cocking assembly and carefully examine both camming surfaces.
There will be one of two possibilities, one is less likely than the other.
Firstly dismantle the cocking assembly and carefully examine both camming surfaces and look for any small dent or discontinuity in the shape near the beginning of the cam especially the cam on the bolt. The likely cause will be due to not completely closing the bolt to it's full extent. This will allow the nose on the cocking piece to impact the cam surface rather than land in the opening provided at the origin of the cocking cam.
The less likely culprit is incorrect hardening on either or both cam surfaces. If this is the case galling might be visible on the softer surface.

I've inspected closely, and there is a wear mark where the cam runs up the ramp(?) and possibly the beginning of a dent where the cam hits the ramp for the first time. Assuming this is the case, a bit of polishing with high grade sand paper an option? As above though, it's sticky the whole action not just to force it free.

Would a bent firing pin be a possibility?

IMG_4986.JPG (157.39 KiB) Viewed 2787 times

Ok, more like 1mm gap rather than .5mm

IMG_4989.JPG (151.49 KiB) Viewed 2787 times

Looks worse in the photo than in person, but could do with a polish?

IMG_4991.JPG (126.13 KiB) Viewed 2787 times

Very hard to get a good photo of the ramp surface with it's curved face.

[JohnV]

You need to systematically look at the possibility of high pressure and if that checks out ok then , thoroughly scrub the inside of the chamber . You have already serviced and lubricated the bolt cam . So you are also having hard bolt lift after " dry firing " . That's unusual . If the cocking cam is smooth and lubricated then check the front of the extractor claw to see if it's rubbing and the cocking piece under the bolt shroud to check it's not jamming on burrs . Something is not working smoothly with it's associated parts . Lubricate the cocking nose and cam face with a dab of moly slide . Or fine moly powder mixed with some light machine oil to make a thick paste . I think the Howa 1500 also has a stronger than usual spring .

[bigpete]

Just wipe it on the curtains......

[deye243]

Just wipe it on the curtains......

[Oldbloke]

Just wipe it on the curtains......

The rifle bolt or your dick?

[straightshooter]

Flyonline
Please look at my version of your picture.
If there is any noticeable wear on the cocking piece nose (the magenta line) then that is an indication of inadequate hardness in the cocking piece.
The cocking cam surface (the green line) should have a smooth burnished mark where there is contact with the cocking piece. Examine it carefully with magnification. If there is a grainy or flakey appearance then that could be due a hardness issue but it could also be due to an excessive friction load from elsewhere in the firing mechanism. The surfaces indicated by the yellow line should be examined and might benefit from being stoned with a small Hard Arkansas stone and light oil. These two surfaces rub on each other with some force when cocking and roughness due to machining marks could be contributing friction between the cocking piece, the bolt shroud and possibly the bolt itself.

[JohnV]

As I mentioned before scrub the chamber real good . A dirty chamber can also cause hard bolt lift . The primers don't indicate any high pressure . Is your brass dirty as that can also add to the issues . Polish up the cases with fine steel wool and fire again in clean dry chamber . Inspect the fired cases for any rings or marks that could indicate a rough chamber job .

[Oldbloke]

Having a little trouble with a sticky bolt lift, but only after firing (dry or on cartridge). I've stripped the firing pin, cleaned the inside of the bolt and the pin with both carbon remover, ran a pipe cleaner through the bolt housing and re-oiled and greased everything but still no dice.

It's only on the lift after firing, without firing it's smooth as butter cocking/de-cocking but when firing it takes maybe 50% more effort than it used to. It came on suddenly and it's enough to annoy me so I'd like to get rid of it if I can as well as remove the possibility of further damage. The only thing I can see is that the cocking assembly doesn't quite sit at the bottom of the cam when in the fired position (like maybe 1/2 mm or so) but I can't compare that with before as I never noticed.

Rifle is Howa 1500

Any ideas or things to look for?

Thanks

Steve

Even with empty chamber.

[JohnV]

His post is confusing on that issue , he also said " it's only on the lift after firing " . He said it came on suddenly so that could be a dirty chamber or even a dirty rough chamber .

[Flyonline]

Thanks for the help guys (Pete, thanks for a laugh )

I'll pull the shroud off and give it a good clean as well as the chamber when I get a chance. Brand new brass (factory) but they have been for a few outings without getting fired so they're not sparkling new.

Flyonline
If there is any noticeable wear on the cocking piece nose (the magenta line) then that is an indication of inadequate hardness in the cocking piece.

Nothing noticeable, but I'll look more closely when I pull it apart. The cam surface does have a wear mark, but I'll need to get a magnifier of some kind to look at it more closely.

[straightshooter]

Flyonline
Your post coincided with a friend having much the same problem which stimulated me to start thinking about possible causes.
Something I neglected to mention in earlier posts regarding why the bolt lift is much lighter when you don't pull the trigger is that the trigger sear is retaining the cocking piece so no work needs to be done to move the cocking piece under spring pressure.

[Oldbloke]

His post is confusing on that issue , he also said " it's only on the lift after firing " . He said it came on suddenly so that could be a dirty chamber or even a dirty rough chamber .

I initially thought a pressure issue but it is pretty clear.

"but only after firing (dry or on cartridge")

[JohnV]

Having a little trouble with a sticky bolt lift, but only after firing (dry or on cartridge). I've stripped the firing pin, cleaned the inside of the bolt and the pin with both carbon remover, ran a pipe cleaner through the bolt housing and re-oiled and greased everything but still no dice.

It's only on the lift after firing, without firing it's smooth as butter cocking/de-cocking but when firing it takes maybe 50% more effort than it used to. It came on suddenly and it's enough to annoy me so I'd like to get rid of it if I can as well as remove the possibility of further damage. The only thing I can see is that the cocking assembly doesn't quite sit at the bottom of the cam when in the fired position (like maybe 1/2 mm or so) but I can't compare that with before as I never noticed.

Rifle is Howa 1500

Any ideas or things to look for?

Thanks

Steve

You need to read it again

[Flyonline]

Not sure what was confusing?

Anyway, pulled the bolt completely apart to components and polished up the tip of the cocking piece nose and the ramp on the cam with a fine wire brush and then polishing wheel with the dremel. Checked for a bent firing pin (nothing I could see) and re-greased and assembled. Worked a little sticky the first couple of lifts after firing but quickly freed up and back to normal, so happy days!

Was unable to get a mop in .30 size at the LGS, so I'll wait until I get one to scrub out the camber as well.

Now just have to change the spring on the trigger to a lighter one and I'll be even happier.

Thanks again all, glad to get to the bottom of that.

[JohnV]

That's good . There was nothing visible on that cocking cam or cocking piece that I could see . As a mop
you can also use Chux Wipe toweling torn into suitable strips lengthwise wrapped on a normal jag ( it only tears lengthwise not across ) , just wrap it up to chamber size .
Also use it to patch the bore wrap smaller . Big rolls are usually available from Bunnings . If it's now cocking ok then the chamber is probably fine anyway . A guy at the range had a weird misfiring issue and sometimes it would not cock easily . I pulled the bolt apart and it had a hard piece of red plastic jammed inside the bolt body interfering with the spring . God knows how that got in there .