Sticky Mauser Bolt

[planetmobius]

I own a beautifil Mauser sporting rifle with a mannlicher stock, claw mounted Hensold Wetzler 4x scope and chambered for 30-06. The receiver is of a military configuration with the thumb slot on the left, however all other parts including the barrel seem to be genuine commercial mauser. The receiver and barrel have matching serial numbers and both have all of the typical commercial proof marks. The original owner brought it back from Germany in 1958 and says that he purchased it there new atthat time. I have no other details.

Anyway, I am having a problem with a sticky bolt. I have only used domestic commercial ammo in this gun such as Remmington or Federal. When I fire the rifle, if I open the bolt immediately, there is no problem. The rifle opens and closes smoothly. But, if I leave the fired case in the chamber for 20 seconds or so while I look throught the spotting scope or something, then the bolt requires a great deal of force to open. I checked the head space with go/no go gauges and it seems to be perfect. The cases show no high pressure symptoms that I can detect. I have inspected the chamber visually and felt for any rough spots and can detect no blemish at all. The rifle is extremely accurate. What up?

 

[rangerruck]

that is because the sticky goo inside the chamber..chamber face/bolt face area, cools,
and it, and the case, becomes stuck together. you need to clean the chamber face verywell.

 

[planetmobius]

That is one of the first things that I considered as well. When I first encountered the problem the gun the gun had just been cleaned. I went over it again anyways thinking that there might have been a stuborn patch that I had missed. I stripped the bolt and when over the whole gun with great care. I then shot it very clean and very dry. Still the same problem.

 

[rangerruck]

I still say it is the same thing; i would say to get you some foaming gunscrubber. Plug the muzzle end, turn upside down so it is resting on the muzzle. Foam that bore up, until the foam is coming out the top of the chamber. as it settles, foam it up more. Leave it this way for about 30 minutes.
empty the sludge out, scrub out the chamber with a brass brush.
if this does not work, then get some jb borepaste, slop it inside the chamber, and around an empty cart, sit in front of a tv, with the muzzle facing slightly upwards, above horizontal. Work the bolt about 1 million times, with the bolt handle in 3, 6, 9, and 12 o'clock postions, about 250k times in each postition.
The paste should scrub out anything that may be sticking in there.

 

[MilsurpShooter]

It's old oil/cosmoline whatever stuck in the small pores of the metal around where the cartridge sits. You fire, it creates heat that liquifies whatevers in the pores of the metal. After some of the heat dissipates it turns back into a sticky paste and grabs the cartridge case.

I've heard of people attaching a 12 guage bore brush to a drill and carefully cleaning it that way. A long soak also works. I've even heard of some putting the barrel in the oven on a low heat and cleaning normally while it's still warm.

If you do a search on the forums here for "Sticky Bolt" you'll find a whole bunch of methods

 

[JesseL]

How does a commercial Mauser in .30-06 get cosmoline or varnish in the chamber? Not that I necessarily doubt you guys, but I've never heard of a problem like this in a commercial rifle shooting non-combloc ammo.

It's not like it would have ever been mothballed by an armory, and I've never heard of steel cased/lacquered .30-06 ammo of any sort.

 

[MilsurpShooter]

Doesn't have to be varnish or cosmoline. Ever seen the tacky, gooey film some of those gun oils leave after they've sat for awhile? Had a bottle of Outers gun oil that I thought ruined my .22 chipmunk. I had put a film of this stuff over it and put it in the safe long term. Was checking it out one day and could barely get it unstuck from the padding. Took a good two hours of scrubbing to get all that gunk off.

I suggested it because it's the most common. If it's not this then you'd start looking at the ammo itself, then the cocking sleeve, then the throat, headspace etc etc... It's a good way to weed out a common problem without having to start spending more money and handing the rifle over to a gunsmith.

Kind of like those times you don't know why your TV won't work, spend hours checking wires, cable box, and then find out it's un-plugged.

 

[rcmodel]

Have you tried cleaning the locking lug recesses in the receiver and putting a little dab of grease on the bolt lugs?

I've seen more then one Mauser with galded bolt lugs because they had never been cleaned or lubed since the day they were made.


rcmodel

 

[Cosmoline]

I'm not entirely convinced that it's goo. It might be, but it could also be just a very minor defect in the chamber that's catching the brass and locking it down when it cools. This might be so small as to be invisible in the chamber itself. Inspect your fired brass carefully, and then maybe take a look with one of those inspection scopes.

 

[planetmobius]

Thanks guys. I will be trying all of the things mentioned above. If that doesn't work, its off to the gunsmith.